The Arthropod Fauna of Oak (Quercus spp., Fagaceae) Canopies in Norway

Abstract

(1) We document the invertebrate fauna collected from 24 oak canopies in east and west Norway as a contribution to the Norwegian Biodiversity Information Centre’s ‘The Norwegian Taxonomy Initiative’. (2) A snap-shot inventory of the canopies was recorded by means of emitting a mist of natural pyrethrum into the canopies at night using a petrol-driven fogger and collecting the specimens in butterfly nets spread on the ground under the canopy. (3) Almost the entire catch of more than 6800 specimens was identified to 722 species. Out of 92 species new to the Norwegian fauna, 21 were new to science and, additionally, 15 were new to the Nordic fauna. Diptera alone constituted nearly half of the species represented, with 61 new records (18 new species). Additionally, 24 Hymenoptera (one new species), six oribatid mites (two new species) and one Thysanoptera were new to the Norwegian fauna. (4) Our study emphasizes the importance of the oak tree as a habitat both for a specific fauna and occasional visitors, and it demonstrates that the canopy fogging technique is an efficient way to find the ‘hidden fauna’ of Norwegian forests. The low number of red listed species found reflects how poor the Norwegian insect fauna is still studied. Moreover, the implication of the IUCN red list criteria for newly described or newly observed species is discussed.

1. Introduction

Pedunculate oak (Quercus robur L.) and sessile oak (Q. petraea (Matt.) Liebl.) are regarded as a biodiversity hotspot in Northern Europe and have been the target of a wide variety of biodiversity studies on arthropods (e.g., [1,2,3,4,5,6,7,8,9,10]).

Relatively few studies have targeted oak canopy invertebrates sampled with canopy fogging methods in Europe but see, e.g., [11,12,13] and chapters in [14]. Efraín Tovar-Sánchez with colleagues, together with a few others (e.g., [15,16,17,18,19,20,21,22,23]), have been pioneers in the Americas on oak canopy studies.

Emitting insecticides into the forest canopy to sample invertebrates has opened up a new area of forest biodiversity research. Originally developed in the tropics, canopy fogging techniques are now being used increasingly in temperate forests to increase the knowledge of European arboreal fauna [11,14,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38]. Stork and colleagues [34] discuss the efficiency of fogging as a method for sampling arthropods from the canopies. A larger spectrum of species is sampled compared with any other single method. This makes fogging a useful method for arthropod snapshot inventories. The major disadvantage is that external and internal feeders are underrepresented (phloem feeders, leaf miners and wood borers), non-obligate occasional by-passers (tourists) will be captured and that the method is sensitive to wind and precipitation [39,40].

This study presents empirical data and analyses of oak canopy invertebrate data from a survey of 24 oak canopies in Norway. We proposed the following hypotheses: 1) there are large geographical differences in species composition and 2) trees on cultivated lands (Berge and Mule Varde) have a different species composition than forest trees. Both hypotheses are related to climatic differences on macro- (H1) and microlevels (H2) (e.g., [41]) as well as the geography of Norway, where oaks are distributed along the coast, usually with scattered populations [42,43]. H2 is founded on the generally more uniform structure of managed lands and lack of a multi-layered canopy of such forest stands [44]. The project was granted by the Norwegian Biodiversity Information Centre as a part of the Norwegian Taxonomy Initiative to search for the hidden life and new species in Norway.

2. Materials and Methods

2.1. The Oaks

Quercus robur and Q. petraea have a sympatric distribution and often hybridize [45], though Q. robur is claimed to be more widespread [42,43]. Thus, we have not distinguished between the two species of oak or their hybrids in this study.

2.2. Site Descriptions

The study was carried out at six sites in southern Norway in June–July 2011 and 2012 (Figure 1,

Table 1. Site details.

Site	County	Municipality	Locality	Georeference	m asl	Sampling Period
1	Vestland	Kvam	Berge	N60.32 E6.17	0–50	21–23 June 2011
2	Vestland	Kvam	Skeianeset	N60.41 E6.35	100–200	28 June–14 July 2012
3	Vestfold and Telemark	Drangedal	Steinknapp	N59.08 E9.04	100–150	28–29 June 2011
4	Vestfold and Telemark	Drangedal	Djupedal	N59.06 E9.22	150–200	2 July 2011 11–12 July 2012
5	Vestfold and Telemark	Porsgrunn	Mule Varde	N59.10 E9.70	0–50	6–10 July 2012
6	Vestfold and Telemark	Larvik	Skjærsjø	N59.20 E9.92	100–150	3–5 July 2012

). All sites were continuous oak-dominated forests, except Berge (site 1) and Mule Varde (site 5), which had oak trees scattered on managed land. Four oaks were treated at each site. The sites were carefully selected to represent a gradient from the inner fjords of West Norway, via known biodiversity hotspots inland Vestfold and Telemark to the coastal areas of SE Norway [8,46,47,48] aligned with the hypotheses.

Site 1 (Berge) is a protected landscape area and classified as IUCN category V [49]. It contains the largest assemblage of old and pruned oak trees in the country. This and the proximity to a lake with specialized swamp vegetation and several old buildings are the main reasons for its protection status [47].

Site 2 (Skeianeset) is a steep slope facing south and has according to one of the highest concentrations of hollow, previously pruned oaks in Norway [46]. The area is characterized by having an unusually high proportion of red-listed species of plants, bryophytes and fungi and is considered to be one of the most important deciduous forests in West Norway [46].

Site 3 (Steinknapp) is a nature reserve that is known to harbor many rare and threatened species (e.g., [48]). Its importance for biological diversity also explains its status as a nature reserve (IUCN category IA). Most likely, large parts of this area were clear-cut in the past as really old oaks are sparsely present and the more or less continuous oak forest is rather homogenous. The oaks treated in this study were just outside of the reserve.

Site 4 (Djupedal) is also a nature reserve protected according to the IUCN IA criteria. In contrast to the nearby site 3, there are several giant oaks in this area and the forest is characterized as old growth. Moreover, the forest is more closed and heterogeneous than at site 3.

Site 5 (Mule Varde) is a cultural heritage site and public park. Large oak trees are scattered throughout the property.

Site 6 (Skjærsjø) is a mixed deciduous forest with larger areas of conifer woods intermixed.

2.3. Data Collection

The trees were chosen to represent ‘typical’ trees in the areas. This implies that after traversing the site, the chosen trees were not at the edges, not standalone trees except for at Berge and Mule Varde where most trees were standalone. Furthermore, the biggest and smallest trees were also avoided. Arthropod sampling was performed by emitting a 1% concentration of natural pyrethrum, Py-Sekt, into the canopy using a Golden Eagle 2610E fogger for approximately 10 minutes in the period between 1 AM and 3 AM on a windless and dry night. Py-sekt contains 1–5% piperonyl butoxide and 0–1% pyrethrum [50]. It breaks down quickly in direct sunlight and is, therefore, relatively safe to use in natural environments [51]. The available space for arthropods will obviously vary both according to the breadth and height of the crown, but for practical reasons we preferred to collect knocked-down invertebrates from a fixed area. Twenty large butterfly nets (18 with Ø50 cm and 2 with Ø100 cm, mesh size from 0.3–0.5 mm) were mounted on the ground or on the lower branches beneath the crown to collect the knocked-down invertebrates, i.e., 5.11 m² of the area beneath each tree was sampled. As so, the proportion of the crown projection area covered will vary slightly between individual trees but is assumed not to affect the qualitative data. The nets remained on the ground for approximately one hour after fogging before the collected material was transferred to 80% ethanol. The material was then sorted and shipped to the co-authors of this paper for identification, with the exception of Lepidoptera and cecidomyiid midges, which remain unidentified.

Most of the material is stored in the Natural History Museum at the University of Oslo and the Norwegian Institute of Bioeconomy Research’s entomological collection. The phorid flies are at the Zoological Museum at Cambridge University, England, and a part of sciarid material, including the holotype of Bradysia quercina Menzel and Köhler, 2014, is deposited at the Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany.

2.4. Species Records

Species designated as new records for Norway or the Nordic countries at the time of identification were based on the individual expert’s consideration, but also on published records in Fauna Europaea [52] and records in the Norwegian Biodiversity Information Centre’s species record database accessed throughout the preparation of this manuscript at www.artsdatabanken.no.

Specimens fully identified to species level were included in the analyses and counted in addition to unidentified species with only one species collected in the respective higher taxon. Uncertain species identifications, i.e., denoted with confer (cf.) or near, were included when the species were not already identified with certainty from other specimens. In cases where the identity of the species was clear, yet undefined (i.e., denoted as sp., sp. 1, etc.), the species beyond the number of identified species were counted. When more unidentified species within the same genus were found, i.e., spp., they were not included in the counts except for counting 1 when no other species in that genus was found. Abundances of common species of spiders and collembolans were sometimes indicated as ‘few’, ‘some’ and ‘many’, and were thence given dummy numbers 5, 10 and 20, respectively.

2.5. Data Analyses

Rarefaction curves extrapolated to three times the sample size, i.e., 72 trees were carried out with EstimateS, version 9.1.0 [53]. The extrapolation relies on statistical sampling methods rather than modeling. Here, the bias corrected form of Chao1 is the asymptotic richness estimator for individual-based abundance data [54]. We chose to extrapolate because rarefaction curves of insect assemblages are usually steep and do not converge unless a massive sampling effort is conducted. However, extrapolation beyond three times the sample size is not recommended [53] because the variance increases with the extrapolation.

Whittaker’s β was calculated as a measure of species turnover along the sampling gradient. It is insensitive to species richness and is calculated as follows:

$$\beta =\left(\frac{\left(\frac{S}{{\alpha }_{max}}\right)-1}{N-1}\right)\times 100$$

(1)

where S = total number of species, α_max = highest number of species in any one locality and N = the number of localities [55]. It ranges from zero (no turnover) to 100 (every locality has a unique set of species). These calculations were performed to complement multivariate analysis using detrended correspondence analysis (DCA) with Canoco, version 4.56 [56] to relate species composition and site characteristics along the sampling gradient. The aim was to investigate whether the species composition within a site differed from the composition of species at the other sites and relate that to environmental characteristics. DCA assumes unimodal species responses to environmental factors in contrast to principal components analysis, or its detrended equivalent, where linear responses are assumed [57]. Therefore, over a longer geographic gradient with different climatic or other underlying environmental factors, DCA is to be preferred. The multivariate analysis was performed on untransformed species abundances with downweighing rare species.

3. Results

3.1. Faunistics

Combined, more than 6800 specimens were identified to 722 species. Ninety-two species (12.7%) were new to the Norwegian fauna upon sampling (

Table A1. Complete list of species with numbers per locality. Literature used for the table: [2,6,10,12,27,38,58,59,60,62,63,64,67,68,69,70,71,78,87,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164], relevant volumes of Die Käfer Mitteleuropas, Danmarks Fauna, Svensk Insektfauna, Fauna Entomologica Scandinavica, and personal comments from the authors. The (B) and (S) in the heading under Kvam are Berge and Skeianeset, respectively, while the (S) and (D) under Drangedal are Steinknapp and Djupedal, respectively. An ¤, * or ** in front of the species name depicts a new record for either science, Norway or Nordic countries upon sampling, respectively. x, xx and xxx represent dummy numbers 5, 10 and 20, respectively.

			Kvam		Drangedal		Porsgrunn	Larvik
Higher Taxon	Species	Habitat	1(B)	2(S)	3(S)	4(D)	5	6
ARANEAE
Anyphaenidae	Anyphaena accentuata (Walckenaer, 1802)	Varies			x			x
Araneidae	Araneus sturmi (Hahn, 1831)	Conifer forests		x		x
	Araniella displicata (Hentz, 1847)				x
Clubionidae	Clubiona brevipes Blackwall, 1841					x		x
Dictynidae	Dictyna pusilla Thorell, 1856				x
Linyphiidae	Agyneta conigera (Cambridge, 1863)							x
	Diplocephalus picinus Blackwall, 1841	Broadleaf forest					x
	Entelecara acuminata (Wider, 1834)		x		x
	Erigone atra Blackwall, 1833	Varies					x
	Maso sundevalli (Westring, 1851)				x
	Moebelia penicillata (Westring, 1851)	Crevices, forests, arboreal				x
	Neriene peltata (Wider, 1834)	Branches, bushes	x	x	x	x		x
	N. radiata (Walckenaer, 1842)				x
	Pelecopsis elongata (Wider, 1834)	Vegetation, dry					x
Mimetidae	Ero furcata (Villers, 1789)	Varies			x
Philodromidae	Philodromus cespitum (Walckenaer, 1802)	Conifer forests				x		x
Pisauridae	Pisaura mirabilis (Clerck, 1757)	Heath, dry			x
Segestriidae	Segestria senoculata (Linnaeus, 1758)	Holes in wall and bark			x
Tetragnathidae	Tetragnatha montana Simon, 1874		x
Theridiidae	Selimus vittatus (C. L. Koch, 1836)		x		x
	Dipoena braccata (C. L. Koch, 1841)	Thermoph., branches			x
	Paidiscura pallens (Blackwall, 1834)	Varies, oak	x	x	x	x	x	x
	Parasteatoda tepidariorum (C. L. Koch, 1841)				x
	Platnickina tincta (Walckenaer, 1802)	Conifer forests			x
	Robertus neglectus (Cambridge, 1871)						x
	Theridion hemerobium Simon, 1914				x
	T. mystaceum L. Koch, 1870	Synantrop, bark, bush					x
Uloboridae	Hyptiotes paradoxus (C. L. Koch, 1834)	Spruce forest			x
Sum species: 28			5	3	17	6	6	6
OPILIONES
Phalangiidae	Lacinius ephippiatus (C. L. Koch, 1835)			12	1	3
	Mitopus morio (Fabricius, 1799)			1				1
Sclerosomatidae	Leiobunum gracile Thorell, 1876						2	1
	Nelima gothica Lohmander, 1945				2
Sum species: 4				2	2	1	1	2
Sum specimens: 23				13	3	3	2	2
ACARI
Anystidae	Anystis baccarum (Linnaeus, 1758)	Predator, woody plants	7	1	272	120	8
Ascidae	Neojordensia sinuata Athias-Henrlot, 1973	Predator			1
Bdellidae	Bdella iconica Berlese, 1923	Predator			1
	B. muscorum Ewing, 1909	Predator			4
	Biscirus silvaticus (Kramer, 1881)	Predator			6	8
Erythraeidae	cf. Abrolophus sp.			1
Eupodidae	Eupodes voxencollinus Thor, 1934					1
Ixodidae	Ixodes ricinus (Linnaeus, 1758)	Mammal parasite	4	4	2			3
Parasitidae	Holoparasitus calcaratus (C. L. Koch, 1839)	Predator			1	2
	Parasitus sp.	Predator					2
Phytoseiidae	Euseius finlandicus (Oudemans, 1915)	Predator, woody plants	1		1
Zerconidae	Zercon spatulatus (C. L. Koch, 1839)	Predator, dry habitats			1			1
Achipteriidae	Achipteria (A.) coleoptrata (Linnaeus, 1758)	Forest litter, meadows,						1
Caleremaeidae	Caleremaeus monilipes (Michael, 1822)	Decaying wood, stumps			1
Camisiidae	Camisia (C.) horrida (Hermann, 1804)	Mosses on trees	2		12	7	1	5
	Heminothrus (Platynothrus) peltifer (C. L. Koch, 1839)	Forest litter, mosses	1					2
Carabodidae	Carabodes (C.) areolatus Berlese, 1916	Lichens, mosses on trees			1
	C. (C.) labyrinthicus (Michael, 1879)	Lichens, mosses on trees		3	1			4
	C. (C.) ornatus Štorkán, 1925	Coniferous forest litter						1
	C. (C.) rugosior Berlese, 1916	Forest litter, stumps,	1
	Odontocepheus (O.) elongates (Michael, 1879)	Forest litter, mosses			1
Cepheidae	Cepheus cepheiformis (Nicolet, 1855)	Forest leaf litter						1
Metrioppiidae	Ceratoppia bipilis (Hermann, 1804)	Forest leaf litter				1
Cymberemaeidae	Cymbaeremaeus cymba (Nicolet, 1855)	Lichens, mosses on trees		1		4		1
Damaeidae	¤Damaeus n.sp.		2	7	9		2	31
Ceratozetidae	Diapterobates humeralis (Hermann, 1804)	Forest litter, mosses			47	2		12
	Trichoribates (T.) trimaculatus (C. L. Koch, 1836)	Forest litter						1
Eremaeidae	Eueremaeus oblongus silvestris Forsslund, 1956	Mosses, leaf litter			5	1	1
Phenopelopodidae	Eupelops acromios (Hermann, 1804)	Mosses, lichens on trees			8	16		4
Euphthiracaridae	Euphthiracarus (E.) cribrarius (Berlese, 1904)	Forest litter, decaying wood	1
Galumnidae	Galumna (G.) lanceata (Oudemans, 1900)	Forest litter						1
Oribatulidae	Hemileius (H.) initialis (Berlese, 1908)	Forest litter, meadows	1		2		1	1
	Oribatula (Zygoribatula) exilis (Nicolet, 1855)	Mosses, lichens on trees		1	13			1
	Phauloppia lucorum (C. L. Koch, 1841)	Lichens on trees	5	6	87	43	6	23
	**P. nemoralis (Berlese, 1916)	Lichens on trees		1	2
Chamobatidae	Chamobates (C.) borealis (Trägårdh, 1902)	Forest litter			1	1		2
	C. (C.) pusillus (Berlese, 1895)	Forest litter	3	2	4	4		1
Liacaridae	**Liacarus (Dorycranosus) splendens (Coggi, 1898)	Decaying wood,			1
	L. (Liacarus) coracinus (C. L. Koch, 1841)	Decaying wood, litter						1
Mycobatidae	Mycobates (M.) parmeliae (Michael, 1884)	Forest litter				2
Oribatellidae	**Oribatella (Oribatella) quadricornuta (Michael, 1880)	Forest litter			14
Phthiracaridae	¤Phthiracarus n. sp.			1	1			3
Steganacaridae	Steganacarus (Tropacarus) carinatus (C. L. Koch, 1841)	Leaf litter in forests			1
Xenillidae	**Xenillus (Xenillus) discrepans Grandjean, 1936	Deciduous forest litter		14			3	1
Sum species: 44			11	12	28	14	8	22
Sum specimens: 907			28	42	500	212	24	101
ISOPODA
Armadillidiidae	Armadillidium pictum Brandt, 1833			14	127	366		8
	A. pulchellum (Zencker, 1799)							2
Oniscidae	Oniscus asellus Linnaeus, 1758		2	2				1
Philosciidae	Philoscia muscorum (Scopoli, 1763)						6
Trachelipodidae	Trachelipus ratzeburgii (Brandt, 1833)	Broadleaf forest				16		3
Sum species: 5			1	2	1	2	1	4
Sum specimens: 547			2	16	127	382	6	14
MYRIAPODA
Chilopoda
Lithobiidae	Lithobius borealis Meinert, 1868				2	3		7
Diplopoda
Julidae	Cylindroiulus punctatus (Leach, 1815)					1
Sum species: 2					1	2		1
Sum specimens: 13					3	6		8
COLLEMBOLA
Bourletiellidae	Bourletiella hortensis (Fitch, 1863)	Vegetation		1
	Deuterosminthurus bicinctus (Koch, 1840)	Vegetation, bushes	8
Dicyrtomidae	Dicyrtomina minuta (O. Fabricius, 1783)	Forest floor	2				3
Entomobryidae	Entomobrya albocincta (Templeton, 1835)	Bark, lichens		3
	E. corticalis (Nicolet, 1842)	Bark, lichens			xx	xx	1
	E. marginata (Tullberg, 1871)	Bark, lichens			x		xx
	E. nicoleti (Lubbock, 1868)	Forest floor		9
	E. nivalis (Linnaeus, 1758)	Bark, lichens	1	90	xxx	xxx	20	xxx
	Lepidocyrtus lignorum (Fabricius, 1793)	Litter		1	xx	x	6	5
	L. violaceus (Geoffroy, 1762)	Litter					1
	Orchesella bifasciata Bourlet, 1839	Moss, rocks, trunks		11	x	xx		3
	O. cincta (Linnaeus, 1758)	Forest floor		3		xx	3
	O. flavescens (Bourlet, 1839)	Forest floor				x	1	1
	Willowsia buskii (Lubbock, 1870)	Xero- thermoph, trunks				x
Hypogastruridae	Xenylla maritima Tullberg, 1869	Xerophilous	1		xx	x
Isotomidae	Isotoma anglicana Lubbock, 1862	Litter					1
	Isotomurus graminis Fjellberg, 2007	Hygrophilous	1
	Pseudisotoma sensibilis (Tullberg, 1876)	Moss, forest floor						2
Katiannidae	Sminthurinus aureus (Lubbock, 1836)	Litter					2
	S. alpinus Gisin, 1953	Bark, dead trees			x
Sminthuridae	Allacma fusca (Linnaeus, 1758)	Forest floor	4	26			9	xx
	Lipothrix lubbocki (Tullberg, 1872)	Forest floor				x		1
	Sminthuridae (juveniles)	Litter	2
Tomoceridae	Pogonognathellus flavescens (Tullberg, 1871)	Forest floor		7
Sum species: 23			6	9	7	9	10	8
DICTYOPTERA
Blattelidae	Ectobius lapponicus (Linnaeus, 1758)				8	2
DERMAPTERA
Forficulidae	Chelidura guentheri (Galvagni, 1994)			7	4	2		2
Sum species: 2				1	2	2		1
Sum specimens: 25				7	12	4		2
EPHEMEROPTERA
Baetidae	Cloeon inscriptum Bengtsson, 1914						1
PLECOPTERA
Nemouridae	Amphinemura borealis (Morton, 1894)	Streams	1
	A. sulcicollis (Stephens, 1836)	Streams			1
	Nemoura cinerea (Retzius, 1783)	Streams			3	10		2
Sum species: 4			1		2	1	1	1
Sum specimens: 18			1		4	10	1	2
HEMIPTERA
Heteroptera
Anthocoridae	Anthocoris nemoralis (Fabricius, 1794)	Predator, arboreal, deciduous					6
	A. nemorum (Linnaeus, 1761)	Predator, vegetation					1	1
	Orius minutus (Linnaeus, 1758)	Predator, varies				1
	Temnostethus gracilis Horváth, 1907	Predator, varies		54	1		81	20
	T. cf. gracilis Horváth, 1907		40	1	52	1		18
Microphysidae	Loricula elegantula (Baerensprung, 1858)	Predator, lichens, trunk	2	2	71	4	19	1
	L. pselaphiformis Curtis, 1833	Predator, lichens, trunk	2	1	3		1
	Indet. (Anthocoridae or Microphysidae)		50		80	2	1	37
Miridae	Blepharidopterus angulatus (Fallén, 1807)	Predator, arboreal, deciduous		1
	Cyllecoris histrionicus (Linnaeus, 1767)	Predator, oak	3		6	3
	Dichrooscytus rufipennis (Fallén, 1807)	Pine flowers and cones					1
	Orthotylus tenellus (Fallén, 1807)	Predator, arboreal, deciduous			2		1
	Phoenicocoris obscurellus (Fallén, 1829)	Pine					3
	Phylus melanocephalus (Linnaeus, 1767)	Predator, oak	15		16	10	36	7
	Phytocoris intricatus Flor, 1861	Conifers			2		1
	Ph. sp.			1	9	1		1
	Psallus confusus Rieger, 1981	Predator, oak					2
	Ps. mollis (Mulsant and Rey, 1852)	Predator, oak			17	4	5	1
	Ps. variabilis (Fallén, 1807)	Predator, oak	1				10
	Ps. varians (Herrich-Schaeffer, 1841)	Predator, arboreal, deciduous	9		27	1	6	1
	Ps. wagneri Ossiannilsson, 1953	Predator, oak			2	1
	Ps. spp.		23	3	84	31	104	1
	Rhabdomiris striatellus (Fabricius, 1794)	Oak	1		5
	Miridae indet.			1				1
Lygaeidae	Scolopostethus thomsoni Reuter, 1875	Varies					1
Pentatomidae	Pentatoma rufipes (Linnaeus, 1758)	Predator, arboreal, deciduous	3	7			5	1
Sum species: 21			9	7	11	9	16	8
Sum specimens:1030			149	71	377	59	284	90
Auchenorrhyncha
Cixiidae	Cixius cunicularius (Linnaeus, 1767)	Deciduous wood plants			1
Delphacidae	Javesella forcipata (Boheman, 1847)	Grass, open habitats						1
	Stiroma affinis Fieber, 1866	Grass, forest		3
	Xanthodelphax flaveolus (Flor, 1861)	Grass						1
Issidae	Issus muscaeformis (Schrank, 1781)	Deciduous wood plants		7	7	15	2
Aphrophoridae	Neophilaenus lineatus (Linnaeus, 1758)	Grass		1			1
Cicadellidae	Alebra albostriella (Fallén, 1826)	Quercus		10		2	7	1
	Edwardsiana frustrator (Edwards, 1908)	Deciduous wood plants					1	1
	E. sp.				1			1
	Eupteryx sp.						1
	Eurhadina concinna (Germar, 1831)	Quercus		5
	Iassus lanio (Linnaeus, 1761)	Quercus				1
	Populicerus populi (Linnaeus, 1761)	Populus tremula			6
	Ribautiana scalaris (Ribaut, 1931)	Quercus				1
	Typhlocyba quercus (Fabricius, 1777)	Prunus / Quercus					1
Sum species: 14				5	4	4	6	4
Sum specimens: 78				26	15	19	13	5
PSOCODEA
Trogiidae	Cerobasis guestfalica (Kolbe, 1880)	Bark	2		3		1	1
Caeciliusidae	Valenzuela burmeisteri (Brauer, 1876)	Conifers, arboreal		1				1
	V. despaxi (Badonnel, 1936)	Conifers, arboreal		1	1
	V. flavidus (Stephens, 1836)	Deciduous, arboreal	11	4	79	31		2
	V. sp.					10
Elipsocidae	Cuneopalpus cyanops (Rostock, 1876)	Conifers, arboreal	1
	Elipsocus abdominalis Reuter, 1904	Bark, lichens					1
	E. moebiusi Tetens, 1891	Bark				11	7
	E. pumilis (Hagen, 1861)	Bark	14		41		1
	E. sp. (moebiusi or pumilis)				1
	Reuterella helvimacula (Enderlein, 1901)	Bark, lichens	1		15	88	18	11
Mesopsocidae	Mesopsocus immunis (Stephens, 1836)	Bark	3				4
	M. laticeps (Kolbe, 1880)	Bark			7
	M. unipunctatus (Müller, 1764)	Bark	16	34	20	18
Psocidae	Amphigerontia bifasciata (Latreille, 1799)	Bark			2	1
	Blaste conspurcata (Rambur, 1842)	Bark, xerophilous			1
	Loensia fasciata (Fabricius, 1787)	Bark		1	4			1
	L. sp. (variegata or pearmani)			1	20			1
	Metylophorus nebulosus (Stephens, 1836)	Bark			6	7	6
	Psococerastis gibbosa (Sulzer, 1776)	Bark	9	22	3		1	47
	Trichadenotecnum sexpunctatum (Linnaeus, 1758)	Bark			3		4
Lachesillidae	Lachesilla quercus (Kolbe, 1880)	Dead branches, leaves			1
Stenopsocidae	Graphopsocus cruciatus (Linnaeus, 1768)	Deciduous, arboreal	3		19	12		1
	Stenopsocus lachlani Kolbe, 1880	Conifers, arboreal			1		2
Philotarsidae	Philotarsus parviceps Roesler, 1954	Bark			2
Peripsocidae	Peripsocus phaeopterus (Stephens, 1836)	Bark				1
	P. subfasciatus (Rambur, 1842)	Bark			6	9
	P. sp. (didymus or phaeopterus)							2
Sum species: 24			9	7	19	9	10	9
Sum specimens: 655			57	64	235	187	45	67
THYSANOPTERA
Aeolothripidae	Aeolothrips melaleucus Haliday, 1852	Predator				1
	A. versicolor Uzel, 1895	Predator				1
Thripidae	Ceratothrips ericae (Haliday, 1836)	Calluna, heath			1			1
	Oxythrips ajugae Uzel, 1895	Pine cones	6
	Taeniothrips picipes (Zetterstedt, 1828)	Herb flowers					1
	Thrips major Uzel, 1895	Herb flowers		4
	T. pini (Uzel, 1895)	Pine						1
Phlaeothripidae	Acanthothrips nodicornis (Reuter, 1880)	Dead branches, bark			1
	Haplothrips sp.				1	1
	Hoplothrips pedicularius (Haliday, 1836)	Stereum rugosus		2	4		1
	H. ulmi (Fabricius, 1781)	Dead wood, fungivore				2
	Phlaeothrips coriaceus Haliday, 1836	Dead wood, fungivore			10
	*Poecilothrips albopictus Uzel, 1895	? Dead wood, fungivore			2	2		1
	Xylaplothrips fuliginosus (Schille, 1911)	Buds, bark, predator			1
Sum species: 14			1	2	7	5	2	3
Sum specimens: 44			6	6	20	7	2	3
TRICHOPTERA
Hydropsychidae	Hydropsyche siltalai Doehler, 1963							2
Limnephilidae	Limnephilus centralis Curtis, 1834				5
Sum species: 2					1			1
Sum specimens: 7					5			2
DIPTERA
Nematocera
Tipulidae	Tipula irrorata Macquart, 1826	Rotten wood, mosses				1
	T. lunata Linnaeus, 1758	Shredder, leaf litter, soil		1
	T. scripta Meigen, 1830	Shredder, leaf litter, green mosses		1			1
	Nephrotoma analis (Schummel, 1833)	Shredder, leaf litter, soil, exposed riverine sediments			1
Limoniidae	**Achyrolimonia neonebulosa (Alexander, 1924)	Rotten wood, fungi, wood sap		1	1
	Austrolimnophila ochracea (Meigen, 1804)	Rotten wood, fungi				1
	Dicranomyia didyma (Meigen, 1804)	Aquatic, semiaquatic, aquatic mosses, algae in waterfalls, shredder		1
	D. mitis (Meigen, 1830)	Leaf litter, soil, exposed riverine sediments, shredder			1	1
	D. modesta (Meigen, 1818)	Leaf litter, soil, exposed riverine sediments, shredder	1		5
	Dicranophragma separatum (Walker, 1848)	Predator, semi-aquatic		1	1			1
	Epiphragma ocellare (Linnaeus, 1761)	Rotten wood			1
	Erioptera lutea Meigen, 1804	Collector, semi-aquatic	1
	Euphylidorea phaeostigma (Schummel, 1829)	Predator, semi-aquatic				1
	Limonia flavipes (Fabricius, 1787)	Leaf litter, soil, under bark, shredder			2
	L. phragmitidis (Schrank, 1781)	Leaf litter, soil, under bark, riverside mud, shredder			1
	Molophilus appendiculatus (Staeger, 1840)	Collector, semi-aquatic		2	3	1
	M. bifidus Goetghebuer, 1920	Collector, semi-aquatic				1
	M. medius de Meijere, 1918	Collector, semi-aquatic			1
	M. ochraceus (Meigen, 1818)	Collector, semi-aquatic			1
	Neolimonia dumetorum (Meigen, 1804)	Rotten wood, fungi						1
	Ormosia lineata (Meigen, 1804)	Collector, semi-aquatic			2
	O. ruficauda (Zetterstedt, 1838)	Collector, semi-aquatic			1	1
	Pilaria discicollis (Meigen, 1818)	Predator, semi-aquatic			2
	*Tasiocera fuscescens (Lackschewitz, 1940)	Collector, semi-aquatic	1		3
Bibionidae	Bibio nigriventris Haliday, 1833	Eurytop, soil	1		1
Psychodidae	Pericoma cf. albomaculata Wahlgren, 1904	Likely saprophagous			1	3
	Psychoda gemina (Eaton, 1904)	Saprophag, semiaquatic					4
	P. phalaenoides (Linnaeus, 1758)	Coprophagous	4		14		1
	P. sp.		2		1	1
	Trichopsychoda hirtella (Tonnoir, 1919)	Saprophagous			2
Anisopodidae	Sylvicola cinctus (Fabricius, 1787)	Rotten wood, fungi			1		6	1
Keroplatidae	Neoplatyura nigricauda (Strobl, 1893)					2
	Orfelia unicolor (Staeger, 1840)				1
Mycetophilidae	Boletina nigricans Dziedzicki, 1885	Mycetophagous			1
	B. sp.	Mycetophagous			1
	Coelosia flava (Staeger, 1840)	Mycetophagous			1
	Ectrepesthoneura sp.	Mycetophagous	1
	Mycetophila sp.	Mycetophagous			1		1
	Mycoma sp.	Mycetophagous			1
	Neuratelia nemoralis (Meigen, 1818)	Mycetophagous			1
	Sceptonia sp.	Mycetophagous			1
	Zygomyia semifusca (Meigen, 1818)	Mycetophagous			1
Sciaridae	Bradysia affinis (Zetterstedt, 1838)	Woodland, wetlands, meadows, gardens, saprophagous			2	2
	B. alpicola (Winnertz, 1867)	Woodland, bogs, grasslands, dunes, saprophagous			1
	*B. fenestralis (Zetterstedt, 1838)	Woodland (oak, hazel, pine), heathland, grassland, water meadows, gardens, saprophagous				1
	B. hilariformis Tuomikoski, 1960	Woodland, wetlands (mires, bogs), saprophagous			1
	B. nitidicollis (Meigen, 1818)	Woodland, heathland, wetlands (water meadows, fens, mires, bogs), grassland, dunes, saltmarsh, gardens, saprophagous	1
	¤B. quercina Menzel and Köhler, 2014	Woodland (oak, ash, aspen, spruce), saprophagous				2
	B. sp. 1	saprophagous		1
	B. sp. 2	saprophagous					1
	B. sp. 3	saprophagous						1
	B. sp. 4	saprophagous	1		1	1
	*Corynoptera forcipata (Winnertz, 1867)	Woodland, heathland, wetlands (incl. water meadows, fens, bogs, basin mires), grassland, coastal landslips, saprophagous		2	1	8
	C. hypopygialis (Lengersdorf, 1926)	Woodland (oak, beech, hazel), calcareous grassland, heathland, wetlands (incl. fens, bogs), open montane habitats, saprophagous			2	3
	*C. irmgardis (Lengersdorf, 1930)	Woodland, heathland, wetlands (incl. water meadows, fens, bogs, reed beds, mires, bogs), grazed grassland, saprophagous					1
	*C. membranigera (Kieffer, 1903)	Woodland (oak, beech, poplar, pine, spruce, conifers), grassland, saprophagous		2	2	2		2
	C. sp. 1	saprophagous				2
	C. sp. 2	saprophagous				1
	C. sp. 3	saprophagous			1
	C. sp. 4	saprophagous		1
	C. sp. 5	saprophagous				1
	C. sp. 6	saprophagous		1
	C. sp. 7	saprophagous			1
	C. sp. 8	saprophagous				1
	C. sp. 9	saprophagous			1
	C. sp. 10	saprophagous			1
	*Cratyna (C.) ambigua (Lengersdorf, 1934)	Woodland (oak, beech, poplar, pine, spruce), calcareous grassland, water meadows, saprophagous	1
	C. sp. 1	saprophagous				1
	Epidapus gracilis (Walker, 1848)	Woodland (oak, beech, maple, larch, pine, spruce, conifers), heathland, bogs, saprophagous						1
	Leptosciarella sp. 1	Xylobiont				1
	Lycoriella ingenua (Dufour, 1839)	Woodland (oak, hazel, poplar), heathland, wetlands (fens, sedge beds, water meadows), parkland, gardens, greenhouses, mycetophagous				1
	*Pseudolycoriella paludum (Frey, 1948)	Woodland (oak, beech, elm), bogs, saprophagous				4
	Scatopsciara atomaria (Zetterstedt, 1851)	Woodland, heathland, wetlands (fens, bogs, mires, water meadows), marshland, grassland, parkland, gardens, saprophagous	4		12		1
	*S. calamophila Frey, 1948	Woodland, grassland, heathland, marshland, gardens, saprophagous			6	2	1
	*S. multispina (Bukowski and Lengersdorf, 1936)	Woodland, grassland, heathland, wetlands (dump meadows, sedge beds), parkland, gardens, saprophagous	3		6
	*S. neglecta Menzel and Mohrig, 1998	Woodland, grassland, heathland, wetlands (water meadows, sedge beds), parkland, gardens, saprophagous				1
	S. pusilla (Meigen, 1818)	Woodland, grassland, heathland, wetlands (bogs, dump meadows), saprophagous			1
	S. vitripennis (Meigen, 1818)	Woodland, grassland, heathland, wetlands (water meadows, fens), parkland, sand dunes, saprophagous	3		8
	S. sp. 1	saprophagous			1
	S. sp. 2	saprophagous				1
	*Trichosia (T.) flavicoxa Tuomikoski, 1960	Woodland, parkland (oak, alder, beech), Xylobiont			1
	T. sp. 1	Xylobiont			1			1
	T. sp. 2	Xylobiont		1
	*Xylosciara trimera Tuomikoski, 1960	Woodland, parkland (oak, beech), xylobiont						1
	X. sp. 1	Xylobiont		1
Ceratopogonidae	Atrichopogon griseolus (Zetterstedt, 1855)				1
	A. minutus (Meigen, 1830)	Rotting material	1
	A. muelleri (Müller, 1905)	Aquatic larvae				1
	A. sp.						1
	Bezzia flavicornis (Staeger, 1839)				1
	Be. ornata (Meigen, 1830)						1
	Brachypogon perpusillus (Edwards, 1921)			1
	Br. sociabilis (Goetghebuer, 1920)		1
	Culicoides chiopterus (Meigen, 1830)	Dung / saprophagous						1
	C. clintoni Boorman, 1984	Peat bogs						2
	C. impunctatus Goetghebuer, 1920	Peat bogs	4	16	36	1	1	30
	C. kibunensis Tokunaga, 1937		1	1	2		1
	C. obsoletus (Meigen, 1818)		1	9		11	2	4
	C. pallidicornis Kieffer, 1919		1		1
	C. pictipennis (Staeger, 1839)						1
	C. scoticus Downes and Kettle, 1952	Dung / saprophagous			2
	C. segnis Campbell and Pelham-Clinton, 1960		3	3	3		1	1
	Dasyhelea spp.			1				1
	**Forcipomyia dichromata Remm, 1968				1
	F. tibialis Remm, 1961			1
	F. titillans (Winnertz, 1852)	Rotting material	6	8	3		1	4
	F. spp.		2		1	1	1	1
	Kolenohelea calcarata (Goetghebuer, 1920)			4
	Palpomyia pubescens Kieffer, 1919			10	1	4	1
	Serromyia femorata (Meigen, 1804)			1			1	1
	Stilobezzia ochracea (Winnertz, 1852)				1
Scatopsidae	Anapausis helvetica Haenni, 1984						12
	A. rectinervis Duda, 1928	Eurytop	1
	Efcookella albitarsis (Zetterstedt, 1850)	Saprophagous	1
	Holoplagia bullata (Edwards, 1925)	Rotting wood, ants (?)				1
	Swammerdamella acuta Cook, 1956		4		1
Chironomidae
Chironominae	Chironomus (Chaetolabis) macani Freeman, 1948		1
	*Chironomus (Lobochironomus) pseudomendax Wülker, 1998		1
	Glyptotendipes (G.) cauliginellus (Kieffer, 1913)		5
	Microspectra nana (Meigen, 1818)		1		2
	M. pallidula (Meigen, 1830)		1
	Parachironomus tenuicaudatus (Malloch, 1915)		1
	Paratendipes albimanus (Meigen, 1818)		2
	Stempellinella brevis (Edwards, 1929)				3
	Tanytarsus medius Reiss and Fittkau, 1971		1
	T. signatus (van der Wulp, 1859)				1
Orthocladiinae	Bryophaenocladius ictericus (Meigen, 1830)			1
	B. cf. vernalis (Goetghebuer, 1921)				2	2		1
	B. sp. 4ES					4	1
	*B. sp. 10ES					1
	Corynoneura lacustris Edwards, 1924				2
	Co. sp. 16ES						1
	Cricotopus glacialis Edwards, 1922				1
	Cr. tibialis (Meigen, 1804)		1
	Eukiefferiella brevicalcar (Kieffer, 1911)				1
	¤Gymnometriocnemus (Gymnometriocnemus) pallidus Stur and Ekrem, 2015		3					1
	Halocladius variabilis (Staeger, 1839)	Marine, intertidal		1	1		4
	Limnophyes asquamatus Søgaard Andersen, 1937				1			1
	L. habilis (Walker, 1856)					1
	L. minimus (Meigen, 1818)		5	1	7	5	2
	L. natalensis (Kieffer, 1914)		2
	L. sp. 3ES						1
	L. sp. 14ES	Parthenogenetic?	2
	Metriocnemus albolineatus (Meigen, 1818)		5		2
	M. fuscipes (Meigen, 1818)		1
	M. picipes (Meigen, 1818)		2		1		1
	M. sp. 3ES						1
	Parametriocnemus stylatus adzharicus Kownacki and Zosidze, 1973		1
	Paraphaenocladius impensus (Walker, 1856)		1				1
	Pseudorthocladius sp. (curtistylus or uniserratus)		2		1		1
	Pseudosmittia albipennis (Goetghebuer, 1921)		2		5	1		3
	P. forcipata (Goetghebuer, 1921)		3		2
	Smittia sp. 8ES		2				1
	S. sp. 16ES		1
	S. sp. 19ES				1
	Tvetenia calvescens (Edwards, 1929)				1
Tanypodinae	Krenopelopia spp.		2	1	1	1
	Zavrelimyia divisa (Walker, 1856)				1
Sum species: 153			47	28	76	41	30	20
Sum specimens: 564			98	75	195	81	55	60
Brachycera
Hybotidae	Bicellaria nigra (Meigen, 1824)	Several habitats	1	1		1
	Drapetis pusilla Loew, 1859				1
	Euthyneura gyllenhali (Zetterstedt, 1838)					1		1
	E. myrtilli Macquart, 1836	Several habitats			5
	Hybos grossipes (Linnaeus, 1767)	Vegetation, predator			2	1		2
	Oedalea stigmatella Zetterstedt, 1842							1
	O. zetterstedti Collin, 1926						1
	Platypalpus calceatus (Meigen, 1822)						1
	P. candicans (Fallén, 1815)		1		3
	P. ciliaris (Fallén, 1816)				1
	P. cothurnatus Macquart, 1827						1
	P. cursitans (Fabricius, 1775)		3		6
	P. ecalceatus (Zetterstedt, 1838)					13
	P. exilis (Meigen, 1822)					2		1
	P. longiseta (Zetterstedt, 1842)				1		4
	P. luteus (Meigen, 1804)		1		1			2
	P. major (Zetterstedt, 1842)			1		2
	P. nigritarsis (Fallén, 1816)	Ground vegetation	1				1	1
	P. pectoralis (Fallén, 1815)			1	1			1
	P. pseudofulvipes (Frey, 1909)						1
	P. verralli (Collin, 1926)				1
	Tachydromia umbrarum Haliday, 1833	Tree trunks, predator	1		2
	Tachypeza fuscipennis (Fallén, 1815)	Tree trunks, predator		1	3	1
	T. nubila (Meigen, 1804)	Tree trunks	1		1			1
	Trichina clavipes Meigen, 1830	Vegetation, predator		3		11	2	3
Empididae	Chelifera trapezina (Zetterstedt, 1838)	Aquatic larvae		1				1
	Empis stercorea Linnaeus, 1761		2		6
	Gloma fuscipennis Meigen, 1822				1
	Hilara canescens Zetterstedt, 1849			1
	H. intermedia (Fallén, 1816)		1
	H. platyura Loew, 1873						1
	Phyllodromia melanocephala (Fabricius, 1794)	Deciduous trees, predator	15	12	9	23	1	17
	Rhamphomyia crassirostris (Fallén, 1816)				1
	R. flava (Fallén, 1816)			1
	Trichopeza longicornis (Meigen, 1822)		1
Atelestidae	Atelestus pulicarius (Fallén, 1816)				2
Dolichopodidae	Chrysotimus flaviventris (von Roser, 1840)			1		21		6
	C. molliculus (Fallén, 1823)						4
	Chrysotus cilipes Meigen, 1824						1
	Dolichopus nigricornis Meigen, 1824					1	1	1
	D. plumipes (Scopoli, 1763)		2		66
	D. popularis Wiedemann, 1817		2		3
	D. simplex Meigen, 1824		3		13
	Gymnopternus aerosus (Fallén, 1823)				1
	G. celer (Meigen, 1824)						1
	Medetera abstrusa Thunberg, 1955	Tree trunks, predator	1
	M. belgica Parent, 1936	Tree trunks, predator	1		1
	Neurigona pallida (Fallén, 1823)				1	1
	N. suturalis (Fallén, 1823)						1
	Sciapus platypterus (Fabricius, 1805)						1
	cf. Sympycnus pulicarius (Fallén, 1823)						3
	Systenus bipartitus (Loew, 1850)	Sap, deciduous trees				1		1
	Xanthochlorus ornatus (Haliday, 1832)						1
	X. tenellus (Wiedemann, 1817)					4
Phoridae
	Borophaga agilis (Meigen, 1830)					1
	*Megaselia albiclava (Schmitz, 1926)				2
	¤M. aliusmyia Disney, 2015				1
	¤M. alphamyia Disney, 2015				2	3
	*M. basispinata (Lundbeck, 1920)		1		1
	¤M. chimyia Disney, 2015					1
	M. ciliata (Zetterstedt, 1848)	Predacious larvae		2		1
	M. conformis (Wood, 1909)						1
	M. cothurnata (Schmitz, 1919)			2	3
	*M. crassipes (Wood, 1909)				1
	¤M. deltamyia Disney, 2015						1
	*M. differens Schmitz, 1948			2	4		1	1
	M. discreta (Wood, 1909)	Fungi		2	2
	M. diversa (Wood, 1909)					1
	¤M. etamyia Disney, 2015			1
	M. fuscovariana Schmitz, 1933				4
	¤M. geiri Disney, 2015				1
	M. giraudii (Egger, 1862)	Decaying material			2		3
	*M. gregaria (Wood, 1910)				2
	*M. hirticrus (Schmitz, 1918)				1		3	1
	*M. hortensis (Wood, 1909)						1
	*M. ignobilis (Schmitz, 1919)			2	14	2	1
	*M. immodensior Disney, 2001		1
	M. insons (Lundbeck, 1920)			1	2			1
	*M. intercostata (Lundbeck, 1921)				3			1
	¤M. karli Disney, 2015				1
	**M. kozlovi Disney, 2013					1	1
	¤M. lambdamyia Disney, 2015				2
	M. lata (Wood, 1910)	Fungi		1
	M. longicostalis (Wood, 1912)	Decaying material						1
	*M. longifurca (Lundbeck, 1921)	Predacious larvae		1
	M. lutea (Meigen, 1830)	Fungi			1
	**M. malhamensis Disney, 1986			1	6	1
	*M. mixta (Schmitz, 1918)	Fungi			1
	**M. nigrescens (Wood, 1910)	Fungi					1
	M. nigriceps (Loew, 1866)	Necrophagous		1	1			2
	¤M. numyia Disney, 2015				2
	¤M. omicronmyia Disney, 2015				1
	M. pectorella Schmitz, 1929				2	1
	*M. protarsalis Schmitz, 1927		1
	M. pusilla (Meigen, 1830)	Polysaprophagous			2
	*M. quadriseta Schmitz, 1918				2
	¤M. rhomyia Disney, 2015				1
	*M. robertsoni Disney, 2008				10
	M. ruficornis (Meigen, 1830)	Decaying materials	1	1	1
	¤M. solii Disney, 2015						1
	*M. speiseri Schmitz, 1929				1
	*M. spinicincta (Wood, 1910)	Fungi			1
	*M. surdifrons (Wood, 1909)			1
	¤M. thunesi Disney, 2015							1
	*M. wickenensis Disney, 2000				1
	¤M. sp. n. H				1
	¤M. sp. n. I				1
	¤M. sp. n. T(5)			1	4		1	1
	M. sp. U							1
	M. sp. 2			1
	M. sp. 3				1		2
	M. sp. 4						1
	M. sp. 6				1	1
	M. sp. 7				1
	M. sp. 8				1
	M. sp. 9				1
	M. sp. 11				1
	M. sp. 12				1
	M. sp. 14				1
	M. sp. 15				1
	M. sp. 17			1	1	1
	M. sp. 18			1
	M. sp. 20			1
	M. sp. 21			1
	Menozziola obscuripes (Schmitz, 1927)	Ant parasitoid			1
	*Phalactrophora fasciata (Fallén, 1823)	Coccinellidae parasitoid		1
	Phora edentata Schmitz, 1920			2	5	21	12
	P. holosericea Schmitz, 1920	Root aphid predator					1
	P. tincta Schmitz, 1920				1
	**Pseudacteon formicarum (Verrall, 1827)	Ant parasitoid	1
Rhagionidae	Ptiolina obscura (Fallén, 1814)		1				1
	Rhagio lineola Fabricius, 1794			4	4	12	5	19
	R. maculatus (DeGeer, 1776)				1
	R. scolopaceus (Linnaeus, 1758)				1
	Symphoromyia crassicornis (Panzer, 1806)				1
Tanypezidae	Tanypeza longimana Fallén, 1820				1
Stratiomyidae	Beris chalybata (Forster, 1771)				1
	B. clavipes (Linnaeus, 1767)		2		14
Tabanidae	Hematopogon sp.				1
Opomyzidae	Opomyza germinationis (Linnaeus, 1758)				1
SciomyzidaE	Pherbellia annulipes (Zetterstedt, 1846)				1
	P. dubia (Fallén, 1820)				3
	P. sp. (rozkosnyi or scutellaris)					1
Lonchopteridae	Lonchoptera sp.							2
Clusiidae	Clusiodes verticalis (Collin, 1912)			1
Lonchaeidae	Lonchaea sp.							1
Milichidae	Phyllomyza sp.						1
Lauxaniidae	*Homoneura lamellata (Becker, 1895)				1
	**H. thalhammeri Papp, 1978						1
	Lyciella decempunctata (Fallén, 1820)			2	7	5		1
	L. platycephala (Loew, 1847)		6	4	17	24		7
	L. rorida (Fallén, 1820)		1		3	1
	L. vittata (Walker, 1849)		1
	Pseudolyciella pallidiventris (Fallén, 1820)			1			1
	P. stylata (Papp, 1978)				2
	P. spp.					2	5
	Sapromyza basalis Zetterstedt, 1847				2
	S. hyalinata (Meigen, 1826)		1		3	1
	Sapromyzosoma quadricincta (Becker, 1895)				1	1
	Tricholauxania praeusta (Fallén, 1820)							2
Drosophilidae	Drosophila sp. (melanogaster or simulans)							1
	Scaptomyza pallida Zetterstedt, 1847				1
Ephydridae	Athyroglossa glabra (Meigen, 1830)				1
Fanniidae	*Fannia pauli Pont, 1997						1
	F. polychaeta (Stein, 1895)					2	1
	F. cf. polychaeta (Stein, 1895)					1
	F. tuberculata (Zetterstedt, 1849)		1
	F. spp.		2		2	1
	Piezura pardalina Rondani, 1866				1
Heleomyzidae	Suillia bicolor (Zetterstedt, 1838)				1
Anthomyiidae	Mycophaga testacea (Gimmerthal, 1834)				1
Muscidae	Coenosia pudorosa Collin, 1953		3
	Helina depuncta (Fallén, 1825)		2	1		1	1	1
	H. impuncta (Fallén, 1825)						1
	Hydrotaea irritans (Fallén, 1823)				1
	cf. Hydrotaea sp.							2
	Muscina levida (Harris, 1780)				1
	Phaonia laeta (Fallén, 1823)					1
	Thricops semicinereus (Wiedemann, 1817)							1
Rhinophoridae	Paykullia brevicornis (Zetterstedt, 1844)			1
	Stevenia atramentaria (Meigen, 1824)					2
Sarcophagidae	Sarcophaga depressifrons Zetterstedt, 1845					1
	S. variegata (Scopoli, 1763)						1
Sepsidae	Sepsis cynipsea (Linnaeus, 1758)		1
Tachinidae	Cinochira atra Zetterstedt, 1845				1
Sum species: 181			31	33	91	37	32	41
Sum specimens: 775			63	64	311	174	86	77
HYMENOPTERA
Formicidae	Camponotus ligniperda (Latreille, 1802)	Woodlands, dead wood		11	35	2	2	6
	Formica fusca Linnaeus, 1758	Xerophilous		2	15	1		2
	F. polyctena Förster, 1850				10	172
	F. rufa Linnaeus, 1761				56
	Lasius brunneus (Latreille, 1798)	Decidous				1	1	1
	L. platythorax Seifert, 1991	Forests	2		25	1
	Myrmica rubra (Linnaeus, 1758)	Forests					7
	M. ruginodis Nylander, 1846	Forests	2	2		2		11
	Temnothorax cf. tuberum (Fabricius, 1775)				3
Crabronidae	Crossocerus tarsatus (Shuckard, 1837)				1
	Passaloecus sp.				1
	Stigmus solskyi Morawitz, 1864				1	1
Ichneumonidae	Gelis sp.	Parasitoid		1
Ceraphronidae	Aphanogmus apicalis Szelenyi, 1938	Parasitoid					1
	A. clavicornis Thomson, 1859	Parasitoid			2
	A. cf. clavicornis sp. 1	Parasitoid		3			3	1
	A. cf. clavicornis sp. 2	Parasitoid						1
	A. cf. clavicornis sp. 3	Parasitoid		1
	A. compressus (Ratzeburg, 1852)	Parasitoid		1	2	4	3	1
	A. nr. compressus (Ratzeburg, 1852)	Parasitoid	1		2		1
	A. nr. dessarti Hellen, 1966	Parasitoid			1
	A. nigrifornicatus Pschom-Walker, 1956	Parasitoid			1
	A. steinitzi Priesner, 1936	Parasitoid				3		1
	A. tenuicornis Thomson, 1859	Parasitoid	1		1	2
	A. nr. tenuicornis Thomson, 1859	Parasitoid	2
	A. spp.	Parasitoid		5		2	3
	*Ceraphron pedes Förster, 1861	Parasitoid				2
	*C. trissacantha Kieffer, 1907	Parasitoid				1
Megaspilidae	Conostigmus sp. 1	Parasitoid		2		3
	C. sp. 2	Parasitoid		1
	Dendrocerus laevis (Ratzeburg, 1852)	Parasitoid			1
	D. sp. 1	Parasitoid	1				1
	D. sp. 2	Parasitoid		1	1
	D. sp. 3	Parasitoid				1
	D. spp.	Parasitoid			1	3
Aphelinidae	*Aphelinus mali (Haldeman, 1851)	Parasitoid, Hemiptera				1
	¤A. quercus Japoshvili and Hansen, 2015	Parasitoid, Quercus			1
	**A. subflavescens (Westwood, 1837)	Parasitoid, Aphidiidae			1
Eulophidae	*Achrysocharoides butus (Walker, 1839)	Parasitoid, Gracillariidae			1
	*A. latreillii (Curtis, 1826)	Parasitoid, Gracillariidae	2		2
	Aprostocetus spp.	Parasitoid		3	1			1
	*Asecodes erxias (Walker, 1848)	Parasitoid, polyphagous	1		1
	Aulogymnus gallarum (Linnaeus, 1761)	Parasitoid, oak-galls		3	1
	Chrysocharis cf. prodice (Walker, 1839)	Parasitoid			1
	C. sp.	Parasitoid,			1
	Cirrospilus diallus Walker, 1838	Parasitoid,	1		2
	Closterocerus trifasciatus Westwood, 1833	Parasitoid, polyphagous			1
	Elachertus sp.	Parasitoid,						1
	Entedon ergias Walker, 1839	Parasitoid, polyphagous		1
	E. sp.	Parasitoid					1
	Eulophus larvarum (Linnaeus, 1758)	Parasitoid, polyphagous		2
	Omphale acamas (Walker, 1839)	Parasitoid		3
	Pediobius eubius (Walker, 1839)	Parasitoid, polyphagous					1
	P. saulius (Walker, 1839)	Parasitoid, polyphagous				1
	P. spp.	Parasitoid			2
	Sympiesis gordius (Walker, 1839)	Parasitoid, polyphagous			2
	S. sericeicornis (Nees, 1834)	Parasitoid, polyphagous		1	1
	**Tamarixia pubescens (Nees, 1834)	Parasitoid, Trioza	4	3	16	4	2	1
	Tetrstichus paululus Graham, 1991	Parasitoid			1
Eupelmidae	Eupelmus annulatus Nees, 1834	Parasitoid, polyphagous		1
Mymaridae	Anagrus sp.	Parasitoid			1
Ormyridae	Ormyrus pomaceus (Geoffroy, 1785)	Parasitoid, oak-galls				1		1
Pteromalidae	Ablaxia parviclava (Thomson, 1878)	Parasitoid, polyphagous			1
	A. sp.	Parasitoid,						1
	Cecidostiba semifascia (Walker, 1835)	Parasitoid, oak-galls						1
	Cyrtogaster vulgaris Walker, 1833	Parasitoid, polyphagous	1	1			1
	Holcaeus stenogaster (Walker, 1836)	Parasitoid			2
	*Hyperimerus pusillus (Walker, 1833)	Parasitoid, Hemiptera	1		1
	Merismus megapterus Walker, 1833	Parasitoid, polyhgagous			1
	Mesopolobus dubius (Walker, 1834)	Parasitoid, oak-galls			1
	M. fasciiventris Westwood, 1833	Parasitoid, oak-galls				1		1
	M. tarsatus (Nees, 1834)	Parasitoid, oak-galls	1		1
	M. tibialis (Westwood, 1833)	Parasitoid, oak-galls	1
	*M. xanthocerus (Thomson, 1878)	Parasitoid, oak-galls		1	1			1
	Miscogaster maculata Walker, 1833	Parasitoid, Agromyzidae				1
	Plutothrix bicolorata (Spinola, 1808)	Parasitoid, Anobiidae	1	1	1
	Pteromalinae sp.	Parasitoid			1
	Seladerma tarsale (Walker, 1833)	Parasitoid, Agromyzidae	6		14	3	1
	Spalangiopelta sp.	Parasitoid		1
	Stenomalina epistena (Walker, 1835)	Parasitoid			1
	S. gracilis (Walker, 1834)	Parasitoid, polyphagous			1
	*Syntomopus thoracicus Walker, 1833	Parasitoid, Agromyzidae			1
	Trigonoderus princeps Westwood, 1832	Parasitoid, Coleoptera			1
Torymidae	Megastigmus dorsalis (Fabricius, 1798)	Parasitoid, oak-galls	9	2	3		1	5
	Torymus flavipes (Walker, 1833)	Parasitoid, oak-galls		5	1
	T. nr. microcerus (Walker, 1833)	Parasitoid		2
Trichogrammatidae	Trichogramma spp.	Parasitoid			1	1
Cynipidae	Ceroptres clavicornis Hartig, 1840	Inquilin in oak-gall	2		5	2
	Neuroterus nr. politus Hartig, 1840	Gall-maker on oak	1
	Saphonecrus connatus (Hartig, 1840)	Inquilin in oak-gall	2		4
	Synergus apicalis Hartig, 1841	Inquilin in oak-gall	6			1		1
	S. crassicornis (Curtis, 1838)	Inquilin in oak-gall				1
	S. gallaepomiformis (Fonscolombe, 1832)	Inquilin in oak-gall			2
	S. pallipes Hartig, 1840	Inquilin in oak-gall					1
Figitidae	*Alloxysta brachyptera (Hartig, 1840)	Parasitoid						1
	A. spp.	Parasitoid			2
Platygastridae	*Amblyaspis angustula Thomson, 1859	Parasitoid					1
	A. tritici (Walker, 1835)	Parasitoid				1
	Euxestonotus spp.	Parasitoid	2	1	3	1		3
	Inostemma hispo Walker, 1838	Parasitoid			2			1
	Platygaster cf. sp. 1	Parasitoid		2
	P. sp. 1	Parasitoid	1			1		1
	P. sp. 2	Parasitoid			1
	P. sp. 3	Parasitoid						1
	P. sp. 4	Parasitoid				1
	P. sp. 5	Parasitoid		1				1
	P. spp.	Parasitoid			1	2	1
	Prosactogaster sp.	Parasitoid					1
	Synopeas sp. 1	Parasitoid			1
	S. sp. 2	Parasitoid	1
Scelionidae	*Telenomus angustatus (Thomson, 1861)	Parasitoid	1		3	1		7
	*T. kolbei Mayr, 1879	Parasitoid			1
	*T. lineolatus Kozlov, 1967	Parasitoid				1
	**T. punctatissimus (Ratzeburg, 1844)	Parasitoid			3
	T. sp. 1	Parasitoid						2
	T. spp.	Parasitoid		3				1
	Trimorus sp.	Parasitoid		1
Diapriidae	Aclista sp. 1	Parasitoid	1			1		1
	A. sp. 2	Parasitoid						1
	*Cinetus piceus Thomson, 1859	Parasitoid					1
	Diapriidae spp.	Parasitoid				1		1
	Diphora sp.	Parasitoid			1
	Entomacis perplexa (Haliday, 1857)	Parasitoid				1
	*Ismarus halidayi Förster, 1850	Parasitoid					1
	*Trichopria aptera (Rhute, 1859)	Parasitoid				1
	*Zygota ruficornis (Curtis, 1831)	Parasitoid				1
	Z. sp. 1	Parasitoid						1
	cf. Zygota sp.	Parasitoid		1			1
Encyrtidae	*Copidosoma floridanum (Ashmead, 1900)	Parasitoid, polyphag				1
	**Habrolepis italicus Delucchi, 1965	Parasitoid, Hemiptera			1
Sum species: 117			26	31	62	36	21	29
Sum specimens: 713			54	69	258	232	36	64
COLEOPTERA
Ptiliidae	Acrotrichis intermedia (Gillmeister, 1845)	Humus, mycetophagous						2
Coccinellidae	Adalia decempunctata (Linnaeus, 1758)	Eurytop, carnivore			1
	Halyzia sedecimguttata (Linnaeus, 1758)	Arboreal, mycetoph		1
Staphylinidae	Atheta vaga (Heer, 1839)	Eurytop, carnivorous					1
	Dexiogyia forticornis (Strand, 1939)	Carnivorous					4
	Eusphalerum luteum (Marsham, 1802)	Eurytop, phytophagous			1
	Haploglossa villosula (Stephens, 1832)	Humus, carnivorous	1
	Holobus flavicornis (Lacordaire, 1835)	Humus, detritivorous			2
	Leptusa fumida (Erichson, 1839)	Bark, carnivorous		4		1
	L. ruficollis (Erichson, 1839)	Bark, carnivorous	7	47	57	30	12	144
	Oxypoda arborea Zerche, 1994	Carnivorous						1
	Phloeocharis subtilissima Mannerheim, 1830	Bark, dead trees	1	1
Scraptiidae	Anaspis marginicollis Lindberg, 1925	Eurytop, phytoph, carniv	4		1			1
	A. rufilabris (Gyllenhal, 1827)	Lignicolous, carnivorous			2	2
	A. thoracica (Linnaeus, 1758)	Eurytop, phytoph, carniv						1
Aderidae	Anidorus nigrinus (Germar, 1842)	Xylophagous, mycetoph		1
Curculionidae	Archarius pyrrhoceras (Marsham, 1802)	Arboreal, Quercus				1
	Brachysomus echinatus (Bonsdorff, 1785)	Humicolous, polyph		1		1
	Coeliodes rana (Fabricius, 1787)	Arboreal, Quercus		1			1
	Hylobius abietis (Linnaeus, 1758)	Conifers		1
	Micrelus ericae (Gyllenhal, 1813)	Calluna, Erica				1
	Orchestes quercus (Linnaeus, 1758)	Arboreal, Quercus	6	1	1	2	1	1
	Otiorhynchus scaber (Linnaeus, 1758)	Arboreal, polyphagous		2	2	1
	O. singularis (Linnaeus, 1767)	Arboreal, polyphagous	2	13	4	11	1
	Polydrusus cervinus (Linnaeus, 1758)	Arboreal, polyphagous						1
	P. tereticollis (De Geer, 1775)	Arboreal, polyphagous	2
	Strophosoma capitatum (De Geer, 1775)	Arboreal, polyphagous			39	34	2	11
	S. melanogrammum (Forster, 1771)	Arboreal, polyphagous		1
Elateridae	Athous haemorrhoidalis (Fabricius, 1801)	Herbs, phytophagous			2
	A. subfuscus (Müller, 1764)	Herbs, carnivorous	3	2	2	1		4
	Dalopius marginatus (Linnaeus, 1758)	Arboreal, polyphagous		1	2			1
	Paraphotistus impressus (Fabricius, 1792)	Arboreal, phytophagous		1
Cryptophagidae	Atomaria fuscata (Schönherr, 1808)	Eurytop, saproph, mycetoph					2
	A. turgida Erichson, 1846	Eurytop, saproph, mycetoph						1
	Cryptophagus setulosus Sturm, 1845	Xerophil, saproph, mycetoph		1				1
Byturidae	Byturus tomentosus (De Geer, 1774)	Arboreal, Rosaceae					1
Cantharidae	Cantharis figurata Mannerheim, 1843	Eurytop, carnivorous	2
	Malthinus flaveolus (Herbst, 1786)	Eurytop, carnivorous		6	6	1		5
	M. seriepunctatus Kiesenwetter, 1851	Thermoph, carnivorous, Quercus		1	3	32
	Malthodes brevicollis (Paykull, 1798)	Carnivorous	2		2	1		3
	M. crassicornis (Mäklin, 1846)	Xerophilous, carniv				1
	M. fuscus (Waltl, 1838)	Eurytop, carnivorous	1	1	2	2		6
	M. guttifer Kiesenwetter, 1852	Arboreal, Salix, carniv		12	1	27	19	2
	M. marginatus (Latreille, 1806)	Arboreal, carnivorous	1		1	3
	M. pumilus (Brebisson, 1835)	Xerophilous, carniv		1	1	1		1
	M. spathifer Kiesenwetter, 1852	Eurytop, carnivorous	5	4	13	5		3
	Podistra rufotestacea (Letzner, 1845)	Eurytop, carnivorous			1
	Rhagonycha lignosa (Müller, 1764)	Eurytop, carnivorous	2		9
	R. lutea (Müller, 1764)	Eurytop, carnivorous		1
	R. nigriventris Motschulsky, 1860	Eurytop, carnivorous	2		4		1
Ciidae	Cis festivus (Panzer, 1793)	Eurytop, mycetoph			1
	C. glabratus Mellié, 1848	Polypor, mycetoph					1
	C. vestitus (Mellié, 1848)	Polypor, mycetoph, Quercus			2			2
	Orthocis alni (Gyllenhal, 1813)	Polypor, mycetoph	1			1
Melandryidae	Conopalpus testaceus (Olivier, 1790)	Xylophagous, mycetoph, Quercus		1	1
	Orchesia micans (Panzer, 1793)	Polypor, mycetoph						11
Latridiidae	Corticarina minuta (Fabricius, 1792)	Eurytop, mycetoph				1
	C. similata (Gyllenhal, 1827)	Eurytop, mycetoph			3	5	2	1
	Cortinicara gibbosa (Herbst, 1793)	Eurytop, mycetoph				2	1
Chrysomelidae	Cryptocephalus labiatus (Linnaeus, 1761)	Arboreal, Quercus						1
	Phratora laticollis (Suffrian, 1851)	Arboreal, Populus		1
Nitidulidae	Cychramus variegatus (Herbst, 1792)	Eurytop, mycetoph				2
	Epuraea unicolor (Olivier, 1790)	Eurytop, saproph					6
Scirtidae	Cyphon coarctatus Paykull, 1799	Hygroph, phytoph	2		6
	C. padi (Linnaeus, 1758)	Hygroph, phytoph, Sphagnum	2
	Prionocyphon serricornis (Müller, 1821)	Eurytop, saproph		2
Dasytidae	Dasytes aeratus Stephens, 1829	Eurytop, carnivorous					1
	D. plumbeus (Müller, 1776)	Eurytop, carnivorous		1
Carabidae	Dromius agilis (Fabricius, 1787)	Arboreal, carnivorous			1			5
	D. angustus Brullé, 1834	Arboreal, carniv, Pinus			2
	D. quadrimaculatus (Linnaeus, 1758)	Arboreal, carnivorous			1		7
	Philorhizus notatus (Stephens, 1827)	Humus, xeroph, carniv					1
Ptinidae	Dryophilus pusillus (Gyllenhal, 1808)	Xylophagous, Pinus						1
	Grynobius planus (Fabricius, 1787)	Xylophagous		1
	Ptinus subpillosus Sturm, 1837	Phytop, saprophagous			1		3	1
	P. villiger (Reitter, 1884)	Humus, xylophagous				1
Histeridae	Gnathoncus buyssoni Auzat, 1917	Eurytop, carnivorous					1
Cerambycidae	Leiopus linnei Wallin, Nylander and Kvamme, 2009	Xylophagous, Quercus			3			1
	Pogonocherus hispidulus (Piller and Mitterpacher, 1783)	Xylophagous, Fagaceae				1
Salpingidae	Salpingus planirostris (Fabricius, 1787)	Bark, carnivorous	4		2	2
Silvanidae	Silvanoprus fagi (Guérin-Ménéville, 1844)	Eurytop, omnivorous			1
Throscidae	Trixagus carinifrons (Bonvouloir, 1859)	Eurytop, arboreal			5
	T. dermestoides (Linnaeus, 1766)	Eurytop, arboreal			10		1
	T. leseigneuri Muona, 2002	Eurytop, arboreal			8
Sum species: 84			19	28	39	29	21	26
Sum specimens 821			50	111	206	173	69	212

), 61 Diptera, 24 Hymenoptera, one Thysanoptera and six oribatid mites. Of these, the following 21 species (2.9%) were new to science: 16 phorid flies (13 described in [25]), one sciarid midge [27], one chironomid midge [58], one aphelinid wasp [59] and two oribatid mites awaiting description. Additionally, of the 92 new Norwegian records, 15 were found in the Nordic countries for the first time (Table A1). Diptera was the most species-rich order of invertebrates with 334 species (46.3%), followed by Hymenoptera with 117 (16.2%) and Coleoptera with 84 (11.6%). Additionally, Diptera was represented with the highest number of specimens with 1339 (19.5%), followed by Hemiptera with 1108 (16.1%) and Coleoptera with 821 (12.0%). Collembola and Araneae were not included in the specimen calculations as their abundances were ranked for the common species. These figures correspond well with other inventories from canopies.

Amongst the sites, the six most species-rich orders were represented in stable proportions with respect to the number of species present (Figure 2), with Diptera being the clearly most species rich at all the sites (29% in Skjærsjø to 47% in Berge). The proportion of specimens for the six most abundant orders, however, showed a varied pattern in that Isopoda constituted 23% of the specimens collected at Djupedal, Hemiptera almost 45% at Mule Varde and Coleoptera 25% at Skjærsjø (Figure 2). Moreover, the number of collected species ranged from 166 in Berge to 370 in Steinknapp, and the number of specimens collected was 4.6 times higher in Steinknapp (2440) than at Berge (536) (

Table 2. Site diversity data. N_Species = Number of species collected from the site. N_Specimens = Number of specimens collected from the site. R_α = Range of species numbers collected from any tree within the site. R_Specimens = Range of specimens collected from any tree within the site. N_Singletons = Number of species represented by one specimen only. Turnover = Whittaker’s β within the site.

	NSpecies	NSpecimens	Rα	RSpecimens	NSingletons	Turnover
Berge	166	536	31–86	83–209	82	31.01
Skeianeset	170	719	40–88	76–324	95	31.06
Steinknapp	370	2440	69–192	278–916	198	30.90
Djupedal	207	1671	8–103	42–787	103	33.66
Mule Varde	174	669	38–80	92–336	111	39.17
Skjærsjø	177	830	52–76	179–230	108	44.30

). Steinknapp contained 1.8 times as many species as the second most species-rich site, Djupedal (just a few kilometers away). Although species new to science were found in all the localities, 14 of the 21 new species were found in Steinknapp (25 specimens) with five species as the second highest number in any of the other localities (Skjærsjø, 37 specimens). In addition, 45 species new to Norway (134 specimens) were found in Steinknapp, followed by 20 species (60 specimens) in Djupedal.

Even though 50.6% of the species (358 species) were represented by singletons and 56.1% (397 species) were found in only one tree (uniques), the turnover along the entire sampling gradient (all 24 trees) was as low as β = 13.34. Rejecting H1, this means that the species communities along the gradient are comparably similar. Between-site turnover showed the same with β = 18.27. Within the sites, however, turnover was higher (Table 2), ranging from 31.01 (Berge) to 44.30 (Skjærsjø). Thus, despite the high turnover within each site (Table 2), the shift in species composition throughout the sampling gradient was comparably lower, indicating that a similar set of species appear in low numbers in geographically disjunct locations.

This separation of sites is also reflected in the DCA ordination diagram (Figure 3), as the two sites on cultivated land (Berge and Mule Varde) were nicely grouped separately from the other sites indicating similar within-site composition of species but different from each other (except tree 11 from Steinknapp), and thus supporting H2. At the opposite side of the gradient, the Djupedal site also indicates a similar species composition within the site, but different from the other sites. The strong explanatory powers of the DCA axes one and two (Eigenvalues = 0.51 and 0.32, respectively), as well as the long gradient (3.98 SD), corroborate this.

3.2. Species Records

3.2.1. Araneae

Spiders are all predators and are usually more associated with their prey than with tree species. Noteworthy though, among the 28 species collected, one threatened species was found (Dipoena braccata (C. L. Koch, 1841), see

Table 3. Red listed species [61]. Categories: VU = vulnerable, NT = near threatened.

Order	Family	Species	Category	Locality	Specimens	Biology
Araneae	Theridiidae	Dipoena braccata (C. L. Koch, 1841)	VU	Steinknapp	Few	Lower branches, conifer forests
Isopoda	Trachelipodidae	Trachelipus ratzeburgii (Brandt, 1833)	NT	Djupedal Skjærsjø	16 3	Broadleaf forest
Coleoptera	Cantharidae	Malthinus seriepunctatus Kiesenwetter, 1852	NT	Skeianeset Steinknapp Djupedal	1 3 32	Thermophilus, predator, Quercus
	Scirtidae	Prionocyphon serricornis (Müller, 1821)	NT	Skeianeset	2	Eurytop, saprophagous
	Dasytidae	Dasytes aeratus Stephens, 1830	NT	Mule Varde	1	Eurytop, predator

). Diplocephalus picinus (Blackwall, 1841) is a species normally found in broadleaf forests, while Moebelia penicillata (Westring, 1851), Paidiscura pallens (Blackwall, 1834), Neriene peltata (Wider, 1834) and Theridion mystaceum L. Koch, 1870 are all known to climb trees [6,60].

3.2.2. Acari

Two oribatid mites new to science were found. Damaeus sp. n. was abundant, with 51 specimens and was present at all the sites except Djupedal, while Phthiracarus sp. n. was found with five geographically disjunct specimens (Table A1). In addition, the following four oribatid species were recorded from the Nordic countries for the first time: Liacarus (Dorycranosus) splendens (Coggi, 1898) with one specimen from Steinknapp, Oribatella (Oribatella) quadricornuta (Michael, 1880) with 14 specimens from Steinknapp, Phauloppia nemoralis (Berlese, 1916) with one specimen from Skeianeset and two from Steinknapp, and Xenillus (Xenillus) discrepans Grandjean, 1936 with 14 specimens from Skeianeset, three from Mule Varde and one from Skjærsjø, respectively.

Among the arboreal species of oribatid mites inhabiting the oak canopies, we can include the following species living in the growths of mosses and lichens therein: Camisia (C.) horrida (Hermann, 1804), Carabodes (C.) areolatus Berlese, 1916, Carabodes (C.) labyrinthicus (Michael, 1879), Cymberemaeus cymba (Nicolet, 1855), Eupelps acromios (Hermann, 1804) and Oribatula (Zygoribatula) exilis (Nicolet, 1855). The following specialized lichenophagous species were also common in the treetops, feeding on the lichen thalluses: Phauloppia lucorum (C. L. Koch, 1841) and Phauloppia nemoralis (Berlese, 1916). The following oribatid species, preferring decaying wood, were also frequent in tree canopies: Caleremaeus monilipes (Michael, 1882), Carabodes (C.) rugosior Berlese, 1916 and Euphthiracarus (E.) cribrarius (Berlese, 1904). Arboreal species are usually bigger (length of body 600–1000 µm), dark brown or black, with a heavily sclerotized cuticle and a thick layer of waxy cerotegument on the body surface, protecting them from desiccation. Forest litter and soil species, on the other hand, are characteristically smaller, lighter in color, with a weaker sclerotized cuticle and a thinner layer of cerotegument (families Tectocepheidae, Oppiidae, Suctobelbidae, Brachychthoniidae, etc.). They were not found in the tree canopies.

3.2.3. Isopoda

Trachelipus ratzeburgii (Brandt, 1833) is categorized as near threatened on the Norwegian red list [61]. It appeared with 16 specimens in Djupedal and three in Skjærsjø (Table 3).

3.2.4. Collembola

Being scavengers for most, springtails are common in trees [62]. All of the 23 species found in the oak canopies can be considered as common species, with Entomobrya nivalis (Linnaeus, 1758) as the most abundant species in this study by far. This species, together with E. albocincta (Templeton, 1835), E. corticalis (Nicolet, 1842), E. marginata (Tullberg, 1871) and Sminthurinus alpinus Gisin, 1953, are known arboreal species being associated with the lichens growing on bark.

3.2.5. Hemiptera

Altogether, 35 species of Hemiptera were collected–21 Heteroptera and 14 Auchenorrhyncha–most of them are oak associates [6,63,64]. Temnostethus gracilis Horváth, 1907 and Phylus melanocephalus (Linnaeus, 1767) were the two most common species of Heteroptera and were found in almost all the sites. Other oak dwellers worth mentioning are, for example, Cyllecoris histrionicus (Linnaeus, 1767), Psallus varians (Herrich-Schaeffer, 1841), P. mollis (Mulsant and Rey, 1852), P. variabilis (Fallén, 1807) and P. wagneri Ossiannilsson, 1953.

3.2.6. Psocodea

Twenty-four species of the order Psocodea were collected from the oak canopies, all belonging to families formerly referred to as the paraphyletic «order Psocoptera» [65,66]. Most Psocodea feed on algae, microfungi and lichens, or decomposing stages of these, as well as pollen. Most of the foliage-living species are associated with either conifers or broadleaved trees, whereas bark-living species (on trunks as well as branches and twigs) are less discriminate. For most Psocodea, the character of the foodstuff itself, which may be dependent on physical factors such as moisture, light and exposure, is probably more important than the tree species. No Psocodea species was found at all the sites, but Reuterella helvimacula (Enderlein, 1901), Valenzuela flavidus (Stephens, 1836) and Mesopsocus unipunctatus (Müller, 1764) were the most common species (see Table A1). Almost all of the collected species are arboreal on a variety of tree species; Lachesilla quercus (Kolbe, 1880) has been believed to be confined to oak [6], but may also be found on other tree species, and outside the distribution of oak. Its apparent association with oak may rather be an expression of its preference [67,68] for dead leaves lingering on the tree, as commonly found on oaks, or on cut-off branches on the ground. Valenzuela flavidus and Graphopsocus cruciatus (Linnaeus, 1768) are associated with foliage of various deciduous trees [6,69].

3.2.7. Thysanoptera

Five specimens of Poecilothrips albopictus Uzel, 1895 were found at the two sites in Drangedal and in Larvik. This species was taken for the first time in Norway and its distribution indicates that it is fairly common. The biology of Thysanoptera is generally poorly known and it cannot be claimed that any of the 14 species in this study are associated with oaks—they are more likely to be associated with substrates offered by the tree, such as fungal spores, algae, etc.

3.2.8. Diptera

This was by far the most species rich group, with 334 species collected, 18 species new to science, 7 species new to the Nordic fauna and an additional 52 species caught in Norway for the first time (Table A1). Phoridae was the family with the largest number of specimens collected (212 specimens), followed by Ceratopogonidae (203) and Chironomidae (123). Phoridae was also the most species rich family by far, with 76 species, of which 16 species were new to science (all of them in the genus Megaselia); in addition, four species were new to the Nordic countries and 23 were new to Norway [25]. Borophaga agilis (Meigen, 1830) was reported new to Norway in [25], but was later found to have been reported in [70]. Sciaridae was the second most species-rich group, with 43 species (one species new to science and eleven new records for Norway) [27,71], followed by Chironomidae with 42 species (one species new to science [58], and two new to Norway). In addition, the following families were represented by new records: Limoniidae and Lauxaniidae (one new to the Nordic countries and one new to Norway, respectively), Ceratopogonidae (one new to the Nordic countries) and Fanniidae (one new to Norway).

The ecology of Diptera is mostly poorly known, and the abundant families in this study, e.g., Phoridae, Ceratopogonidae and Chironomidae, are usually neglected in general faunistic surveys. Only adults were identified, while habitat requirements are a characteristic of the larvae of most species in these families. Nonetheless, most of the species in the sciarid genera Bradysia, Corynoptera and Scatopsciara in this study (see Table A1) might have a connection with oak trees beyond accidental visits, as they are mentioned as deciduous forest species in the literature [27,72]. Other species of Sciaridae are also mentioned as deciduous forest associates (see Table A1). Additionally, Phyllodromia melanocephala (Fabricius, 1794) (Empididae) and Systenus bipartitus (Loew, 1850) (Dolichopodidae) are species known to inhabit deciduous forests. The first was one of the most common species, with 77 specimens collected and from all the sites.

Many species of Diptera are known to be trunk dwelling, fungivores or associated with rotting wood, habitats that are present abundantly in old oak trees. A rather high proportion of the collected species, where ecological information is available, can be assigned to either of these categories, most of them with few specimens. One exception was Forcipomyia titillans (Winnertz, 1852), a rotting matter associate [73], which was found with 22 individuals.

Other individual species accounts worth mentioning are those being abundant at all the sites or aggregated at any one site. Culicoides impunctatus Goetghebuer, 1920 (Ceratopogonidae) is a haematophagous parasite on vertebrates and is also known to aggregate close to the breeding sites, which are humid areas, preferably peat bogs [74]. It was abundant in Steinknapp and Skjærsjø in particular, with 36 and 30 specimens collected, respectively. Phora edentata Schmitz, 1920 (Phoridae), a species new to Norway, was fairly abundant at most of the sites, which indicates that it is a rather common species. Two other species, Rhagio lineola Fabricius, 1794 (Rhagionidae) and Lyciella platycephala (Loew, 1847) (Lauxaniidae) were abundant in most sites. Both of these species are common and occupy many habitats. Twelve specimens of Anapausis helvetica Haenni, 1984 (Scatopsidae) were collected from Mule Varde and not from elsewhere. This species is rarely collected, but present knowledge may indicate an association with open areas, farmlands and parks [75]. Platypalpus ecalceatus (Zetterstedt, 1838) (Hybotidae) was collected with 13 individuals and only in Djupedal. This species is most likely a predator, as are nearly all Empidoidea (Terje Jonassen, pers. comm), but we cannot readily explain why it appears aggregated at only one site. We can see a similar pattern for two other Empidoidea, the dolichopodids Chrysotimus flaviventris (von Roser, 1840) and Dolichopus plumipes (Scopoli, 1763), being represented with 21 and 66 specimens in the Drangedal samples, respectively, and almost absent from all the other sites (see Table A1). Ten specimens of Megaselia robertsoni Disney, 2008 (Phoridae), a species new to Norway, were found only at Steinknapp.

3.2.9. Hymenoptera

A total of 117 species of Hymenoptera were collected, with one species new to science, four species new to the Nordic countries and 21 additional species new to Norway (Table A1). Many of the specimens could only be identified to genera or ‘near to’ designated species. Thus, we cannot rule out that there are additional undescribed species in this material. Of the two suborders, Symphyta and Apocrita were represented only by Apocrita. Of the 118 species, 12 Aculeata, i.e., nine Formicidae and three Crabronidae, were found, with the remaining 106 species all belonging to the ‘Parasitica infraorder’. Ceraphronoidea with 22 species (68 specimens); Chalcidoidea, 55 species (160); Cynipoidea, nine species (31); Diaprioidea, 11 species (15); Platygastroidea, 21 species (56). The Ichneumonoidea superfamily was not processed, only one species of Gelis sp. (1) has been added to the list. Ants in the mound building Formica rufa group, namely F. polyctena (Förster, 1850) were, not surprisingly, the most abundant species. They were all collected in Drangedal and from all the treated trees at Djupedal. None of the remaining species were abundant in any of the sites, but 30 specimens of Tamarixia pubescens (Nees, 1834) (Eulophidae), a new species to the Nordic fauna, were collected and taken at all the sites. This is a parasitoid of psyllids known to parasitize Trioza remota Förster, 1848 [76], which, as nymph, is an oak obligate. T. remota was, however, not found in this study. Seladerma tarsale (Walker, 1833) (Pteromalidae) was also rather common with 24 specimens, whereof 14 were collected in Steinknapp. This species is a primary parasitoid of Agromyzidae flies [77]. No Agromyzidae were present in the material, however.

The representation of species shows a well-defined association with oak-galls. The oak-galls living inquilins are Ceroptres clavicornis Hartig, 1840, Neuroterus nr. politus Hartig, 1840, Saphonecrus connatus (Hartig, 1840), Synergus apicalis Hartig, 1841, S. crassicornis (Curtis, 1838), S. gallaepomiformis (Fonscolombe, 1832) and S. pallipes Hartig, 1840, all of which are in the Cynipidae family. Of the large number of oak-gall parasitoids the following are worth mentioning: Aulogymnus gallarum (Linnaeus, 1761) (Eulophidae), Eupelmus annulatus Nees, 1834 (Eupelmidae), Ormyrus pomaceus (Geoffroy, 1785) (Ormyridae) and the pteromalids Cecidostiba semifascia (Walker, 1835), Mesopolobus dubius (Walker, 1834), M. fasciiventris Westwood, 1833, M. tarsatus (Nees, 1834), M. tibialis (Westwood, 1833), M. xanthocerus (Thomson, 1878), Megastigmus dorsalis (Fabricius, 1798) and Torymus flavipes (Walker, 1833).

3.2.10. Coleoptera

Of the 84 species of beetles found, the following three are on the Norwegian red list: Malthinus seriepunctatus Kiesenwetter, 1851 (Cantharidae), Prionocyphon serricornis (Müller, 1821) (Scirtidae) and Dasytes aeratus Stephens, 1830 (Dasytidae) (Table 3), all of which are categorized as near threatened in [61].

Several of the following species are associated with oak or oak habitats: the curculionid Archarius pyrrhoceras (Marsham, 1802), Coeliodes rana (Fabricius, 1787), Orchestes quercus (Linnaeus, 1758), the already-mentioned cantharid M. seriepunctatus, the ciid Cis vestitus (Mellié, 1848), the melandryid Conopalpus testaceus (Olivier, 1790), the chrysomelid Cryptocephalus labiatus (Linnaeus, 1761) and the cerambycid Leiopus linnei Wallin, Nylander and Kvamme, 2009 [10,36,78]. Furthermore, many species are known to be arboreal (see Table A1) but being rare in this material was common for most of them. A common, arboreal species was Otiorhynchus singularis (Linnaeus, 1767) (Curculionidae), which is a species found almost everywhere. Thirty-one specimens were found at all the sites but Skjærsjø. Another weevil, Strophosoma capitatum (De Geer, 1775), a common herbivore on broadleaf trees, was found with 86 specimens at all but the two sites in Western Norway. The predacious Cantharidae Malthodes guttifer Kiesenwetter, 1852 was collected at all the sites, except for Berge, with a total of 61 specimens. This is a common species associated with shrubs and often found climbing trees [10]. Eleven specimens of Orchesia micans (Panzer, 1793) (Melandryidae) were taken in Skjærsjø, its only appearance in the study. It has a close association with polypore fungi in the genus Inonotus [79]. The throscid Trixagus dermestoides (Linnaeus, 1767) was found with 11 specimens, ten of them from Steinknapp. This species is known as a generalist pollen and mold feeder (e.g., [80]), with habitats plentiful in oaks.

3.2.11. Species Accumulation

The number of invertebrate species collected was 722 and with an overall turnover of 13.34, suggesting a rather homogenous species pool along the sampling gradient, thus rejecting H1. Despite the apparent homogeneity, there is a logarithmic relationship between the number of specimens collected and the number of species found (Figure 4), suggesting that a much more profound sampling effort needs to be performed before the accumulation curve starts to converge. A steep species accumulation curve is to be expected, as the sample size was low and there was a high number of singletons and uniques.

4. Discussion

4.1. Invertebrate Samples

The number of collected specimens in this study was very low compared with the material collected from a comparable study of 24 pine trees over a geographic gradient from west to east Norway, and where nearly 30,000 specimens were collected using the same methodology [38]. One explanation is fairly obvious, as the weather in both sampling periods (June/July 2011/2012) was generally cool and wet. The monthly temperature in 2011 was, on average, slightly higher than the normal temperature (ranging from −0.1 °C below (Kvam, June) to +1.7 °C above (Kvam, July)), but the precipitation ranged from 104% (Kvam, July) to 270% (Drangedal, July) of the normal [81,82]. For the year 2012, the monthly temperature was lower than the normal temperature (from −1.8 °C (Drangedal, June) to −0.2 °C (Kvam, July) below), and these months were also generally wetter than the normal (from 69% (Kvam, June) to 169% (Kvam, July)) [83,84]. Other reasons for the low catch may be related to the structure and complexity of the oak canopy compared with the more open canopy of, for example, pine, in that a larger proportion of the invertebrates remain in the tree—either stuck in the dense foliage or on the branches [40].

4.2. Faunistics

Despite the fact that the ecology is unknown for many species (see Table A1), a large proportion of the species found in this study must be assumed to be occasional visitors (i.e., the oak canopy is not their primary habitat). As oaks offer a wide selection of sites to rest, swarm and feed, an abundance of generalists is to be assumed, as well as opportunists taking advantage of the secondary habitats in the trees, for example, the ant Camponotus ligniperda (Latreille, 1802) living in dead parts of the tree or the numerous species associated with deposited leaf litter or soils. Yet, a few other species are likely to be accidental visitors from the surroundings, e.g., species associated with grasses and Calluna (see Table A1). The presence of the marine chironomid Halocladius variablis (Stæger, 1839) in Steinknapp is surprising, as the distance to the ocean is about 30 km. Its presence in Skeianeset and Mule Varde makes sense, however, as both sites are close to the sea.

Even though neither the psyllid Trioza nor agromyzid flies were found as adults, we must believe them to be present, as parasitoids of both were common—Tamarixia pubescens (Eulophidae) and Seladerma tarsale (Pteromalidae), respectively. Both host groups are known to live on oaks [85,86]. Another fact to note is that no species of the egg parasitoid family Mymaridae (Chalcidoidea) were collected. Mymaridae are among the smallest insects in the world and, regarding the number of species and specimens collected, it is inconceivable that Mymaridae species would not be present in larger numbers as well. Unfortunately, due to their size and fragility, they are likely to remain in the canopy foliage after fogging.

Correspondence in the presence of species over a broader selection of the literature shows that 80 of the species collected in this study were also present in other European studies on oak canopy or oak tree faunas [2,6,9,10,36,60,63,64,69,78,87,88].

4.3. Conservation and Distribution of Invertebrates

Some paradoxes arise when comparing the number of red-listed species with the number of species new to science or new occurrences. Only five red-listed species were found, while the number of new occurrences, including new species, were 92 altogether, most of them with very few specimens. This demonstrates how poorly known the Norwegian arboreal invertebrate fauna still is. One of the criteria for inclusion on the Red List is that a species should be known to reproduce for more than 10 years in the period 1800–2015 [61]. Moreover, rarity is not a criterion for inclusion as such, but reduced population sizes, reduced habitats or reduced distributions are. Thus, the value of the red list category for a species is based on the changes in the intermediate-term development of its population and no new species or species observations will qualify for considerations into the list, but it should incentivize the monitoring of those species. Inasmuch, a new species does not necessarily have to be rare, it may just have been overlooked. Several new species or occurrences were widespread and with intermediate numbers, e.g., Damaeus n. sp. (50 specimens, five localities), Xenillus (Xenillus) discrepans (18 specimens, three localities), Tamarixia pubescens (30 specimens, all localities), Megaselia ignobilis (19 specimens, four localities) and Phora edentata (40 specimens, four localities) (Table A1). Canopy specialists may well have been overlooked, as some are, apparently, rarely collected using conventional techniques and the obvious inaccessibility to the canopy complicates sampling.

Oaks used to be evenly distributed within its distributional range in Norway, and fragmentation was caused by overexploitation and a colder climate in the beginning of the sub-Atlantic era [89]. The rejection of H1 can be a response to a historically continuous distribution of oaks by the remaining relic populations of invertebrates. Additionally, compared with the more diverse forest sites, the poorer community of plants, homogeneous canopy structure [44] and different microclimate [41,90] in the actively managed sites, Mule Varde and Berge, are likely to source a different fauna to the oak trees on these sites, thus, supporting H2.