RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pe...RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pests attacking solanaceous plants in Asia.In this study,the potential of dietary RNAi to manage H.vigintioctopunctata was investigated using both in vitro synthesized and bacterially expressed double-stranded RNAs(dsRNAs)of HvvATPase A and HvvATPase E.The expression levels of HvvATPase A and HvvATPase E were higher in Malpighian tubules than in other tissue types.The silencing of HvvATPase A and HvvATPase E led to significant mortality in H.vigintioctopunctata larvae.In addition,the ingestion of HvvATPase A and HvvATPase E significantly deterred feeding behavior and subsequently arrested the development of H.vigintioctopunctata.Notably,the bacterially expressed dsRNAs consistently caused higher mortality in larvae and adults.Finally,the nontarget effects of the dsRNAs of H.vigintioctopunctata on the predatory ladybeetle Propylaea japonica were evaluated.P.japonica 1st instar larvae were administered vATPase A and vATPase E dsRNAs from H.vigintioctopunctata and P.japonica under the worst-case scenario,in which dsGFP served as negative control.There were significant effects of dsHvvATPase A on P.japonica at the transcriptional level but not at the organismal level,whereas dsHvvATPase E did not effect P.japonica at either the transcriptional or the organismal level.Collectively,the results of the study suggest that HvvATPase A and HvvATPase E can act as novel molecular targets for the control of H.vigintioctopunctata.展开更多
Despite their positive effect in reducing pest populations, exotic generalist predators sometimes become invasive and contribute to the displacement of indigenous species in the same trophic level. Although laboratory...Despite their positive effect in reducing pest populations, exotic generalist predators sometimes become invasive and contribute to the displacement of indigenous species in the same trophic level. Although laboratory experiments have linked intraguild predation （IGP） to these interactions, field evidence and quantification of IGP are still lacking for most systems. The recent establishment of the exotic Harmonia axyridis （Pallas） （Coleoptera： Coccinellidae） in Italy raises concern about the detrimental effect that the ladybird could have on native coccinellids. Here we assessed, under laboratory conditions, the acceptability and suitability of eggs of 2 native ladybirds, Adalia bipunctata L. and Oenopia conglobata （L.）, as prey items for H. axyridis larvae. Then we developed primers for molecular gut-content analysis to detect predation by H. axyridis on the 2 ladybirds and on the aphid Eucallipterus tiliae L. Species-specific 16S primers were developed for the 3 species and laboratory feeding trials were conducted to quantify the rate of prey DNA breakdown in the gut of//. axyridis. Moreover, to field evaluate primers, H. axyridis 4th instars （n = 132） were systematically collected from linden trees in northern Italy and screened for the presence of prey DNA. Seventy-three percent and 7% of field collected H. axyridis were positive for aphid and coccinellid DNA, respectively. Predation upon aphid and A. bipunctata was lower than predicted if density dependent consumption was expected, while predation upon O. conglobata was significantly higher. Here, we provided the first evidence of IGP among feral populations ofH. axyridis and indigenous ladybird beetles, occurring in Italy.展开更多
基金supported by the National Key R&D Program of China(2017YFD0200900)National Natural Science Foundation of China(31972269)GDUPS(2017).
文摘RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pests attacking solanaceous plants in Asia.In this study,the potential of dietary RNAi to manage H.vigintioctopunctata was investigated using both in vitro synthesized and bacterially expressed double-stranded RNAs(dsRNAs)of HvvATPase A and HvvATPase E.The expression levels of HvvATPase A and HvvATPase E were higher in Malpighian tubules than in other tissue types.The silencing of HvvATPase A and HvvATPase E led to significant mortality in H.vigintioctopunctata larvae.In addition,the ingestion of HvvATPase A and HvvATPase E significantly deterred feeding behavior and subsequently arrested the development of H.vigintioctopunctata.Notably,the bacterially expressed dsRNAs consistently caused higher mortality in larvae and adults.Finally,the nontarget effects of the dsRNAs of H.vigintioctopunctata on the predatory ladybeetle Propylaea japonica were evaluated.P.japonica 1st instar larvae were administered vATPase A and vATPase E dsRNAs from H.vigintioctopunctata and P.japonica under the worst-case scenario,in which dsGFP served as negative control.There were significant effects of dsHvvATPase A on P.japonica at the transcriptional level but not at the organismal level,whereas dsHvvATPase E did not effect P.japonica at either the transcriptional or the organismal level.Collectively,the results of the study suggest that HvvATPase A and HvvATPase E can act as novel molecular targets for the control of H.vigintioctopunctata.
文摘Despite their positive effect in reducing pest populations, exotic generalist predators sometimes become invasive and contribute to the displacement of indigenous species in the same trophic level. Although laboratory experiments have linked intraguild predation （IGP） to these interactions, field evidence and quantification of IGP are still lacking for most systems. The recent establishment of the exotic Harmonia axyridis （Pallas） （Coleoptera： Coccinellidae） in Italy raises concern about the detrimental effect that the ladybird could have on native coccinellids. Here we assessed, under laboratory conditions, the acceptability and suitability of eggs of 2 native ladybirds, Adalia bipunctata L. and Oenopia conglobata （L.）, as prey items for H. axyridis larvae. Then we developed primers for molecular gut-content analysis to detect predation by H. axyridis on the 2 ladybirds and on the aphid Eucallipterus tiliae L. Species-specific 16S primers were developed for the 3 species and laboratory feeding trials were conducted to quantify the rate of prey DNA breakdown in the gut of//. axyridis. Moreover, to field evaluate primers, H. axyridis 4th instars （n = 132） were systematically collected from linden trees in northern Italy and screened for the presence of prey DNA. Seventy-three percent and 7% of field collected H. axyridis were positive for aphid and coccinellid DNA, respectively. Predation upon aphid and A. bipunctata was lower than predicted if density dependent consumption was expected, while predation upon O. conglobata was significantly higher. Here, we provided the first evidence of IGP among feral populations ofH. axyridis and indigenous ladybird beetles, occurring in Italy.
