Invasive alien pest insect species represent a major threat for agriculture and biodiversity. Because chemical treatments employed to contrast such pests elicit serious environmental and human health problems, a great...Invasive alien pest insect species represent a major threat for agriculture and biodiversity. Because chemical treatments employed to contrast such pests elicit serious environmental and human health problems, a great effort is currently directed to develop long term and environmentally friendly biological control strategies. However, the successful application of some promising techniques, such as the Sterile Insect Technique （SIT）, requires a deep knowledge of the pest basic biology. Here, we argue that understanding pest sexual biology using a social network approach can significantly improve the performance of con- trol strategies. For example, SIT may benefit from understanding how individuals interact and how males accede to reproduction, in order to target the most reproductively active and polygamic males. In this paper we studied the socio-sexual networks of the Asian red palm weevil （RPW） Rhynchophorusferrugineus, a worldwide invader which is causing heavy economic impacts on several palm species. We found that the RPW has a highly promiscuous mating system, characterized by forced interruptions of pair copulations by additional males. The social network is highly non-random nor regular： few males almost monopolize repro- duction, behaving as key-players in the network of matings. Additionally, males have a stable pattern of sexual behaviour over time. We use RPW social network as a case study to direct the development of management techniques such as SIT strategy [Current Zoology 61 （1）： 85-97, 2015].展开更多
Parasites and pathogens can follow different patterns of infection depending on the host developmental stage or sex.In fact,immune function is energetically costly for hosts and trade-offs exist between immune defense...Parasites and pathogens can follow different patterns of infection depending on the host developmental stage or sex.In fact,immune function is energetically costly for hosts and trade-offs exist between immune defenses and life history traits as growth,de-velopment and reproduction and organisms should thus optimize immune defense through their life cycle according to their developmental stage.ldentifying the most susceptible target and the most virulent pathogen is particularly important in the case of insect pests,in order to develop effective control strategies targeting the most vulnerable individuals with the most effective control agent.Here,we carried out laboratory tests to identify the most susceptible target of infection by infecting different stages of the red palm weevil Rhynchophorus ferrugineus(larvae,pupae,male,and female adults)with both a generic pathogen,antibiotic-resistant Gram-negative bacteria Escherichia coli XL1-Blue,and two specific strains of entomopathogenic nematodes(EPNs),Steinernema carpocapsae ItS-CAO1 and Heterorhabditis bacteriophora ItH-LUI.By evaluating bacterial clearance,host mortality and parasite progeny release,we demonstrate that larvae are more resistant than adults to bacterial challenge and they release less EPNs progeny after infection despite a higher mortality compared to adults.Considering the two EPN strains,S.carpocapsae was more virulent than II.bacteriophora both in terms of host mortality and more abundant progeny released by hosts after death.The outcomes attained with unspecific and specific pathogens provide useful information for a more efficient and sustainable management of this invasive pest.展开更多
文摘Invasive alien pest insect species represent a major threat for agriculture and biodiversity. Because chemical treatments employed to contrast such pests elicit serious environmental and human health problems, a great effort is currently directed to develop long term and environmentally friendly biological control strategies. However, the successful application of some promising techniques, such as the Sterile Insect Technique （SIT）, requires a deep knowledge of the pest basic biology. Here, we argue that understanding pest sexual biology using a social network approach can significantly improve the performance of con- trol strategies. For example, SIT may benefit from understanding how individuals interact and how males accede to reproduction, in order to target the most reproductively active and polygamic males. In this paper we studied the socio-sexual networks of the Asian red palm weevil （RPW） Rhynchophorusferrugineus, a worldwide invader which is causing heavy economic impacts on several palm species. We found that the RPW has a highly promiscuous mating system, characterized by forced interruptions of pair copulations by additional males. The social network is highly non-random nor regular： few males almost monopolize repro- duction, behaving as key-players in the network of matings. Additionally, males have a stable pattern of sexual behaviour over time. We use RPW social network as a case study to direct the development of management techniques such as SIT strategy [Current Zoology 61 （1）： 85-97, 2015].
文摘Parasites and pathogens can follow different patterns of infection depending on the host developmental stage or sex.In fact,immune function is energetically costly for hosts and trade-offs exist between immune defenses and life history traits as growth,de-velopment and reproduction and organisms should thus optimize immune defense through their life cycle according to their developmental stage.ldentifying the most susceptible target and the most virulent pathogen is particularly important in the case of insect pests,in order to develop effective control strategies targeting the most vulnerable individuals with the most effective control agent.Here,we carried out laboratory tests to identify the most susceptible target of infection by infecting different stages of the red palm weevil Rhynchophorus ferrugineus(larvae,pupae,male,and female adults)with both a generic pathogen,antibiotic-resistant Gram-negative bacteria Escherichia coli XL1-Blue,and two specific strains of entomopathogenic nematodes(EPNs),Steinernema carpocapsae ItS-CAO1 and Heterorhabditis bacteriophora ItH-LUI.By evaluating bacterial clearance,host mortality and parasite progeny release,we demonstrate that larvae are more resistant than adults to bacterial challenge and they release less EPNs progeny after infection despite a higher mortality compared to adults.Considering the two EPN strains,S.carpocapsae was more virulent than II.bacteriophora both in terms of host mortality and more abundant progeny released by hosts after death.The outcomes attained with unspecific and specific pathogens provide useful information for a more efficient and sustainable management of this invasive pest.
