Search Results (6)

The cross-hybridization of American chestnut (Castanea dentata (Marsh.) Borkh.) with Chinese chestnut (Castanea mollissima Bl.) is a promising strategy for restoring a blight-resistant strain of this keystone species to the Appalachian mountains. To assess the ecological impacts of hybridization on invertebrate communities, we conducted a study across chestnut plots with varying degrees of hybridization (75%, 94%, or 100% American chestnut). Our findings indicate American chestnut hybridization impacted invertebrate communities above- and belowground. Aboveground insect community composition, insect herbivory, gall infestation, and belowground invertebrate diversity were all altered. While some of these differences could be explained by different growth habits or environmental differences, stark differences in Asian chestnut gall wasp infestation (Dryocosmus kuriphilus Yasumatsu.) suggest a genetic component. These results suggest that chestnut hybridization, and particularly expanded restoration efforts using chestnut hybrids, could impact invertebrate communities above- and belowground in addition to pest dynamics. Understanding these effects is crucial for successful chestnut restoration and ecosystem management. Full article

The gall midge Lasioptera donacis, whose larval stage interferes with the reed’s leaf development, is a potential candidate agent for the biological control of Arundo donax. Reed infestation is always associated with the presence of a saprophytic fungus, Arthrinium arundinis, which is believed to provide food for the larvae. Larvae also interact with a parasitic nematode, Tripius gyraloura, which can be considered its natural enemy. To deepen our knowledge of the plant–fungus–insect trophic interactions and to understand the effects of the nematode on midge larval feeding behaviour, we applied stable isotope analysis, one of the most effective methods for investigating animal feeding preferences in various contexts. The results showed that on average the fungus accounted for 65% of the diet of the midge larvae, which however consumed the reed and the fungus in variable proportions depending on reed quality (expressed as the C:N ratio). No differences in feeding behaviour were observed between parasitised and non-parasitised midge larvae, indicating that nematodes have no effect in this regard. Due to its trophic habits, L. donacis could be an effective control agent of A. donax and these results need to be considered when implementing biological control measures. Full article

Gut microbiome balance plays a key role in human health and maintains gut barrier integrity. Dysbiosis, referring to impaired gut microbiome, is linked to a variety of diseases, including cancers, through modulation of the inflammatory process. Most studies concentrated on adenocarcinoma of different sites with very limited information on gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). In this study, we have analyzed the gut microbiome (both fungal and bacterial communities) in patients with metastatic GEP-NENs. Fecal samples were collected and compared with matched healthy control samples using logistic regression distances utilizing R package MatchIt (version 4.2.0, Daniel E. Ho, Stanford, CA, USA). We examined differences in microbiome profiles between GEP-NENs and control samples using small subunit (SSU) rRNA (16S), ITS1, ITS4 genomic regions for their ability to accurately characterize bacterial and fungal communities. We correlated the results with different behavioral and dietary habits, and tumor features including differentiation, grade, primary site, and therapeutic response. All tests are two-sided and p-values ≤ 0.05 were considered statistically significant. Gut samples of 34 patients (12 males, 22 females, median age 64 years) with metastatic GEP-NENs (22 small bowel, 10 pancreatic, 1 gall bladder, and 1 unknown primary) were analyzed. Twenty-nine patients had well differentiated GEP-neuroendocrine tumors (GEP-NETs), (G1 = 14, G2 = 12, G3 = 3) and five patients had poorly differentiated GEP-neuroendocrine carcinomas (GEP-NECs). Patients with GEP-NENs had significantly decreased bacterial species and increased fungi (notably Candida species, Ascomycota, and species belonging to saccharomycetes) compared to controls. Patients with GEP-NECs had significantly enriched populations of specific bacteria and fungi (such as Enterobacter hormaechei, Bacteroides fragilis and Trichosporon asahii) compared to those with GEP-NETs (p = 0.048, 0.0022 and 0.034, respectively). In addition, higher grade GEP-NETs were associated with significantly higher Bacteroides fragilis (p = 0.022), and Eggerthella lenta (p = 0.00018) species compared to lower grade tumors. There were substantial differences associated with dietary habits and therapeutic responses. This is the first study to analyze the role of the microbiome environment in patients with GEP-NENs. There were significant differences between GEP-NETs and GEP-NECs, supporting the role of the gut microbiome in the pathogenesis of these two distinct entities. Full article

In the last decade, Botryosphaeria dothidea has been steadily reported as an associate of gall midges (Diptera, Cecidomyiidae) in a variety of host plants and ecological settings. This cosmopolitan fungus is well-known for its ability to colonize many plant species, as both a pathogen and an endophyte. Thus, the shift from this general habit to a lifestyle involving a strict symbiotic relationship with an insect introduces expectancy for possible strain specialization which could reflect separated phylogenetic lineages. Considering the recent taxonomic revision concerning species of Botryosphaeria, we evaluated the phylogenetic relationships among strains recovered from Asphondylia galls collected on several species of Lamiaceae in Poland and in Italy, and all the currently accepted species in this genus. A number of strains previously characterized from gall samples from Australia and South Africa, whose genetic marker sequences are deposited in GenBank, were also included in the analysis. As a result, full identity as B. dothidea is confirmed for our isolates, while strains from the southern hemisphere grouped separately, indicating the existence of genetic variation related to the geographic origin in the association with gall midges. Full article

In 2003, a new gall-inducing wasp of the genus Ophelimus was detected in the Valparaíso Region (Chile), affecting tree plantations of Eucalyptus globulus Labill and Eucalyptus camaldulensis Dehnh. Since then Ophelimus has been frequently detected in different plantations in Chile, covering a widespread area. A preliminary collaborative study suggests that the micro-wasp detected should be classified as a new Ophelimus species. In this paper, using an integrative approach (including genetic, morphological, and behavioral data), we addressed the delimitation and description of this new species. This study involved the use of brood adult specimens, raised at the laboratory of MIPlagas Ltda., from infested twigs of E. globulus collected in several localities between of Valparaíso and Los Lagos Regions (Chile). Morphological structures were described according to current Eulophidae taxonomic keys, as well as additional traits, such as gall morphology and behavior. Genetic characterization was implemented using a phylogenetic approach, based on a 648 bp specific fragment of the mitochondrial Cytochrome Oxidase I gene (COI 5 region) obtained from collected specimens and available databases (Genbank, NCBI, and BOLDSystem). Specifically, distinctive patterns of variation were detected in traits like gall and antennae morphology, growth habit trends, and a notorious polyphenism in the setae from the sub marginal vein. Overall evidence suggests that this new entity should be considered a new species in Ophelimus, which is henceforth named Ophelimus migdanorum Molina-Mercader. Full article

The paper records the rediscovery of the rare Urodontidius enigmaticus Louw, 1993 in South Africa, based on specimens reared from galls in the succulent leaves of Ruschia versicolor. The original account of some of the morphological characters of the species is corrected, and its habitus, antennae, pygidium and genitalia are illustrated. Its life history and galling habit on its host plant are described and illustrated, and its larva is compared with those of the genera Urodontellus Louw and Urodontus Louw, which represent different larval types with different life histories. The silk-spinning habits of the Urodontellus larva are briefly described. A tribute to the late Schalk Louw is presented, together with a list of his publications on weevils. Full article