Three New Species of Aceria (Acari: Trombidiformes: Eriophyoidea) from China

Simple Summary The superfamily Eriophyoidea includes more than 5000 species worldwide and is a group of phytophagous mites that has an important influence on the agricultural economy. Aceria is a rich genus of more than 1000 species that belongs to the family Eriophyidae, which is distributed throughout the whole world. Here, three new species, Aceria bischofiae sp. nov., Aceria cryptocaryae sp. nov., and Aceria buddlejae sp. nov., from Guangxi and Chongqing Province, China (the Oriental realm), are described and illustrated. Abstract Three new Aceria species from South China are described and illustrated. Aceria bischofiae sp. nov. was collected on Bischofia javanica Blume (Phyllanthaceae), inducing galls on surfaces of the leaves; Aceria cryptocaryae sp. nov. was collected on Cryptocarya metcalfiana Allen (Lauraceae), causing the formation of erinea on the undersurface of the leaves; and Aceria buddlejae sp. nov. was collected as a vagrant on Buddleja lindleyana Fort. (Scrophulariaceae) leaves, and no symptoms were observed on the host plant.


Introduction
Eriophyoidea (Acari: Prostigmata) is a large mite superfamily and among the smallest arthropods known.Until now, more than 5000 named species have been recognized, some of which are significant pests of agronomic plants [1,2], and over 80% of eriophyoid mite species are monophagous, registered on only one host plant [3,4].Host plants supposedly played key roles in their diversification [5].
Aceria Keifer is the genus of the family Eriophyidae Nalepa with the highest number of known species.Until now, more than 1000 species names of Aceria have been reported around the world, of which about 81 species have been found in China [6-10].However, some species within Aceria are described too simply, and their taxonomic status needs to be further clarified through more detailed morphological descriptions and comprehensive taxonomic methods.
Bischofia javanica Blume is an evergreen tree belonging to the family Phyllanthaceae, broadly distributed in China, India, Bangladesh, and Southeast Asia.The nutritional value of this plant is very high, and the leaves are widely used in the preparation of salads and condiments [11].Until now, three eriophyoid mites have been described from the plants of the genus Bischofia: Phyllocoptruta maerimae Boczek and Chandrapatya, 2000; Bischofius kanchanaburi Boczek and Chandrapatya, 2000; and Diptilomiopus bischofiae Li, Wei, and Wang, 2009 [12,13].Buddleja lindleyana Fort. is a garden ornamental plant and also a commonly used medicinal plant that belongs to the family Scrophulariaceae, which is native to China and mainly distributed in most parts of southern China.It is also distributed in America, Malaysia, Africa, and so on [14].To date, one eriophyoid mite has been described from the plants of the genus Buddleja: Aculops salviifoliae Meyer and Ueckermann, 1990 [15].Cryptocarya metcalfiana Allen belongs to the family Lauraceae, which is distributed in South China.Only one eriophyoid mite has been described from the plants of the genus Cryptocarya: Aceria aphanothrix (Nalepa, 1923) [16].
This paper presents descriptions of three new Aceria species: Aceria bischofiae sp.nov., Aceria cryptocaryae sp.nov., and Aceria buddlejae sp.nov.from the subtropical zone of China (the Oriental Region).

Materials and Methods
Mite specimens were collected from different host plants in Guangxi and Chongqing provinces by the aid of a hand lens (80×) (brand: Binyun; model: BY2600; manufacturer: Xinxiang Optics, Hangzhou, China) in China.The mites were collected from leaf samples and stored in a 70% ethanol solution using a brush.Samples were slide-mounted in modified Berlese medium [17] without adding additional fibers [18].All specimens were examined with an Olympus CX41 (Philippines) microscope under phase contrast (oil immersion: 100×/1.25;widefield eyepiece: 10×).Micrographs were obtained from a Nikon DS-Ri2 microscope.The morphological terminology used in the morphological description of the mites follows Lindquist [1] and Amrine et al. [19], and internal female genitalia nomenclature follows Chetverikov [20].The generic classification follows Amrine et al. [19] in combination with descriptions of all the published genera after 2003.All morphological measurements were according to Amrine and Manson [17], as modified by de Lillo et al. [18].Measurements refer to the length of the morphological trait unless otherwise specified and are given in micrometers (µm).The holotype female measurement precedes the corresponding range for paratypes (given in parentheses).For males, only the ranges are given.Moreover, "*" in the descriptions means there is no variation in measurements.The number of measured specimens (n) is given within parentheses in the description of each stage.Line drawings were prepared according to de Lillo et al. [18], and abbreviations used in figures follow Amrine et al. [19].Host plant names and their synonymies are in accordance with The World Flora Online "http://www.worldfloraonline.org/" (30 May 2023).
Type materials are deposited at the Key Laboratory of Beibu Gulf Environment Change and Resources Utilization of the Ministry of Education, Nanning Normal University, Guangxi, China.
Relation to the host plant: mites induce small round galls on the surfaces of the leaves (Figure 3A,B).
Etymology: the species is named after the generic name of the type of host plant, i.e., Bischofia, in the genitive case.
Differential diagnosis: Aceria bischofiae sp.nov.appears to be close to Aceria varia (Nalepa, 1892), which was originally found on Populus tremula L. (Salicaceae) in France and Iran [21,22].Aceria bischofiae sp.nov.and A. varia have similar short median line at the basal third of shield, numerous short lines on the outer side of the shield, empodium 5-rayed, genital coverflap with 14-16 longitudinal ridges, but they differ by the number This new species also has few morphological similarities to Aceria lagerstroemiae Kuang and Yang, 1994, collected on Lagerstroemia indica L. in China [23], including coxal ornamentation (with 15-18 longitudinal ridges), coxae smooth, setae h1 absent, number of dorsal semiannuli (65-70), scapular setae sc length, as well as the length of ventral setae d, e, and f.The new species can be differentiated for prodorsal shield ornamentation (median line and admedian lines present on about posterior half of the shield, a few short dashes medially and some short and long dashes on the lateral margin of the shield in A. bischofiae sp.nov.versus shield ornamented several lines in A. lagerstroemiae), the number of empodium rays (5-rayed in A. bischofiae sp.nov.versus 6-rayed in A. lagerstroemiae), and the shape of microtubercles on dorsal semiannuli (with elongate microtubercles in A. bischofiae sp.nov.versus with semi-oval microtubercles in A. lagerstroemiae).This new species also has few morphological similarities to Aceria lagerstroemiae Kuang and Yang, 1994, collected on Lagerstroemia indica L. in China [23], including coxal ornamen-tation (with 15-18 longitudinal ridges), coxae smooth, setae h1 absent, number of dorsal semiannuli (65-70), scapular setae sc length, as well as the length of ventral setae d, e, and f.The new species can be differentiated for prodorsal shield ornamentation (median line and admedian lines present on about posterior half of the shield, a few short dashes medially and some short and long dashes on the lateral margin of the shield in A. bischofiae sp.nov.versus shield ornamented several lines in A. lagerstroemiae), the number of empodium rays (5-rayed in A. bischofiae sp.nov.versus 6-rayed in A. lagerstroemiae), and the shape of microtubercles on dorsal semiannuli (with elongate microtubercles in A. bischofiae sp.nov.versus with semi-oval microtubercles in A. lagerstroemiae).4 and 5

Discussion
According to the data from the published references, there are 84 species (including 3 new species in this paper) of the genus Aceria that have been found in China, parasitizing 34 families and 77 species of plants [9].Among them, 7 Aceria

Discussion
According to the data from the published references, there are 84 species (including 3 new species in this paper) of the genus Aceria that have been found in China, parasitizing 34 families and 77 species of plants [9].Among them, 7 Aceria species of host plants belong to the family Salicaceae, and 5 Aceria species of host plants, respectively, belong to the families Poaceae and Solanaceae.In relation to the host plants of Aceria, 41 species cause galls on leaves, 8 species cause the formation of erinea on the undersurface of the leaves, and 29 species causes vagrants on the leaves.In terms of the geographical distribution and floral distribution of Aceria, there are 66 species in Oriental realm and 24 species in the Palearctic realm.Aceria kuko (Kishida, 1927) and Aceria lycopersici (Massee, 1939) are distributed in most areas of China; Aceria dispar (Nalepa, 1891) and Aceria tosichella Keifer, 1969, are widely distributed in northern China; Aceria litchii (Keifer, 1943) and Aceria hupehensis Kuang and Hong, 1995, are widely distributed in southern China; others are only distributed in local areas.The discovery of three new Aceria species in China indicates that the species richness of the genus is still underestimated.Undoubtedly, it is necessary to further collect and investigate the taxa of Aceria in the future to understand their real diversity.
However, there are still some problems in the classification of the genus Aceria.Due to the limitations of early microscopic techniques and the low standards for the description of new species of Aceria, many Aceria species were not described in detail when they were published.The quality of illustrations was poor or no illustrations, the host plants were not identified, the damage description of Aceria to the host plants was simple, and the naming was irregular, which led to the emergence of a large number of homonyms in Aceria in recent years.For example, the Aceria species studied by Nalepa were stored in the Vienna Museum of Natural History in the United States.Due to long-term poor management, the alcohol-soaked specimens had dried up, the slide specimens could not be observed, the original manuscripts were lost, and many type specimens could not be verified [18,28].Therefore, there are still some known Aceria species that need to be collected again for supplementary description and revision.In addition, most Aceria species are mainly distinguished by similar characteristics such as dorsal shield decoration, the number of dorsal and ventral rings, the genital coverflap decoration, the number of empodium, and so on.The distinguishing features of some closely related species are very subtle, and there may be certain differences on the same host in different regions [29][30][31].Therefore, a combination of molecular and morphological methods is needed to determine the taxonomic status of species.

Conclusions
In this research, we described three new Aceria species: Aceria bischofiae sp.nov., Aceria cryptocaryae sp.nov., and Aceria buddlejae sp.nov.We also summarized the number of species, host plants, and geographical distribution of the genus Aceria in China.However, because Aceria species in northern China have not been systematically investigated yet, it is safe to assume that many other Aceria species may exist and will eventually be discovered.