Polyphagous insect species develop using multiple host plants.Often considered beneficial,polyphagy can also be costly as host nutritional quality may vary.Drosophila suzukii(Matsumura)is an invasive species that can ...Polyphagous insect species develop using multiple host plants.Often considered beneficial,polyphagy can also be costly as host nutritional quality may vary.Drosophila suzukii(Matsumura)is an invasive species that can develop on numerous fruit species over the annual cycle.Here,we assessed the contribution of winter-available fruit to the development of seasonal populations of D.suzukii,under fluctuating late winter/early spring temperature regimes.We infested an artificial diet and three suitable fruit species available in winter/early spring(Aucuba japonica,Elaeagnus×submacrophylla,Viscum album)with D.suzukii larvae under three temperature regimes:constant 20℃,fluctuating controlled regime of 8-15℃(12 h of light at 8℃ and 12 h of dark at 15℃),and uncontrolled outdoor regime during spring.As expected,fly performance was impaired by early spring-like environmental conditions,whatever the development diet,and the winter fruit were suboptimal diets compared to the artificial diet,whatever the thermal regime.However,under cold fluctuating temperature regimes,the ranking of fruit supporting the best performance changed,highlighting the occurrence of physiological trade-offs.Winter-acclimated females preferentially oviposited in A.japonica and/or E.×submacrophylla,whatever the thermal regime,which does not support the preference-performance hypothesis.This finding is also discussed in the context of D.suzukii management strategies.展开更多
Unlike other dung beetles, the Iberian geotrupid, Thorectes lusitanicus, exhibits polyphagous behavior; for example, it is able to eat acorns, fungi, fruits, and carrion in addition to the dung of different mammals. T...Unlike other dung beetles, the Iberian geotrupid, Thorectes lusitanicus, exhibits polyphagous behavior; for example, it is able to eat acorns, fungi, fruits, and carrion in addition to the dung of different mammals. This adaptation to digest a wider diet has physiological and developmental advantages and requires key changes in the composition and diversity of the beetle＇s gut microbiota. In this study, we isolated aerobic, facultative anaerobic, and aerotolerant microbiota amenable to grow in culture from the gut contents of T. lusitanicus and resolved isolate identity to the species level by sequencing 16S rRNA gene fragments. Using BLAST similarity searches and maximum likelihood phylogenetic analyses, we were able to reveal that the analyzed fraction （culturable, aerobic, facultative anaerobic, and aerotolerant） of beetle gut microbiota is dominated by the phyla Pro- teobacteria, Firmicutes, and Actinobacteria. Among Proteobacteria, members of the order Enterobacteriales （Gammaproteobacteria） were the most abundant. The main functions associated with the bacteria found in the gut of T. lusitanicus would likely include nitrogen fixation, denitrification, detoxification, and diverse defensive roles against pathogens.展开更多
基金funded by ANR(Agence Nationale de la Recherche française)in the context of the project ANR DROTHERMAL(Grant Number:ANR-20-CE02-0011-01).
文摘Polyphagous insect species develop using multiple host plants.Often considered beneficial,polyphagy can also be costly as host nutritional quality may vary.Drosophila suzukii(Matsumura)is an invasive species that can develop on numerous fruit species over the annual cycle.Here,we assessed the contribution of winter-available fruit to the development of seasonal populations of D.suzukii,under fluctuating late winter/early spring temperature regimes.We infested an artificial diet and three suitable fruit species available in winter/early spring(Aucuba japonica,Elaeagnus×submacrophylla,Viscum album)with D.suzukii larvae under three temperature regimes:constant 20℃,fluctuating controlled regime of 8-15℃(12 h of light at 8℃ and 12 h of dark at 15℃),and uncontrolled outdoor regime during spring.As expected,fly performance was impaired by early spring-like environmental conditions,whatever the development diet,and the winter fruit were suboptimal diets compared to the artificial diet,whatever the thermal regime.However,under cold fluctuating temperature regimes,the ranking of fruit supporting the best performance changed,highlighting the occurrence of physiological trade-offs.Winter-acclimated females preferentially oviposited in A.japonica and/or E.×submacrophylla,whatever the thermal regime,which does not support the preference-performance hypothesis.This finding is also discussed in the context of D.suzukii management strategies.
文摘Unlike other dung beetles, the Iberian geotrupid, Thorectes lusitanicus, exhibits polyphagous behavior; for example, it is able to eat acorns, fungi, fruits, and carrion in addition to the dung of different mammals. This adaptation to digest a wider diet has physiological and developmental advantages and requires key changes in the composition and diversity of the beetle＇s gut microbiota. In this study, we isolated aerobic, facultative anaerobic, and aerotolerant microbiota amenable to grow in culture from the gut contents of T. lusitanicus and resolved isolate identity to the species level by sequencing 16S rRNA gene fragments. Using BLAST similarity searches and maximum likelihood phylogenetic analyses, we were able to reveal that the analyzed fraction （culturable, aerobic, facultative anaerobic, and aerotolerant） of beetle gut microbiota is dominated by the phyla Pro- teobacteria, Firmicutes, and Actinobacteria. Among Proteobacteria, members of the order Enterobacteriales （Gammaproteobacteria） were the most abundant. The main functions associated with the bacteria found in the gut of T. lusitanicus would likely include nitrogen fixation, denitrification, detoxification, and diverse defensive roles against pathogens.
