Host preference of the bean weevil Zabrotes subfasciatus  

作　　者：Isabel Ribeiro do Valle Teixeira Angel Roberto Barchuk Fernando Sergio Zucoloto 

机构地区：[1]Department of Biology, Centro Universitario da Fundacao Educacional de Guaxupe, Minas Gerais [2]Department of Biology, Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Sao Paulo [3]Department of Biological Sciences, Universidade Federal de Alfenas, UnifaI-MG, Alfenas, Minas Gerais, Brazil

出　　处：《Insect Science》2008年第4期335-341,共7页昆虫科学（英文版）

摘　　要：It is largely known that the range of an insect diet is mostly determined by oviposition behavior, mainly in species with endophytic larvae such as Zabrotes subfasciatus. However, the proximate factors determining host choice and the subsequent steps leading to the expansion or reduction of the host number and occasional host shifts are largely unknown. We analyzed various factors determining host preference of Z. subfasciatus through the evaluation of： （i） oviposition preference of a wild population of Z. subfasciatus on the usual host （bean） and unusual hosts （lentil, chickpea and soy）, and the performance of the offspring; （ii） artificial selection for increasing preference for hosts initially less frequently chosen; （iii） comparison of oviposition behavior between two different populations （reared for -30 generations in beans or chickpeas, respectively）; （iv） oviposition timing on usual and unusual hosts; and （v） identification of preference hierarchies. We found that when using unusual hosts, there is no correlation between performance and preference and that the preference hierarchy changes only slightly when the population passes through several generations on the less frequently accepted host. We also found a positive response to artificial selection for increasing oviposition on the less preferred host; however, when the host-choice experiment involved two varieties of the usual host, the response was faster than when the choice involved usual and unusual hosts. Finally, beetles reared on an unusual host （chickpea） for 26 generations showed similar good fitness on both usual and unusual hosts, indicating that the use of a new host does not necessarily result in the loss of performance on the original host. Nevertheless, this population showed lower fitness on the usual host than that of the original population, suggesting an underlying partial trade-off phenomenon which may contribute to a broadening of diet of this insect species.It is largely known that the range of an insect diet is mostly determined by oviposition behavior, mainly in species with endophytic larvae such as Zabrotes subfasciatus. However, the proximate factors determining host choice and the subsequent steps leading to the expansion or reduction of the host number and occasional host shifts are largely unknown. We analyzed various factors determining host preference of Z. subfasciatus through the evaluation of： （i） oviposition preference of a wild population of Z. subfasciatus on the usual host （bean） and unusual hosts （lentil, chickpea and soy）, and the performance of the offspring; （ii） artificial selection for increasing preference for hosts initially less frequently chosen; （iii） comparison of oviposition behavior between two different populations （reared for -30 generations in beans or chickpeas, respectively）; （iv） oviposition timing on usual and unusual hosts; and （v） identification of preference hierarchies. We found that when using unusual hosts, there is no correlation between performance and preference and that the preference hierarchy changes only slightly when the population passes through several generations on the less frequently accepted host. We also found a positive response to artificial selection for increasing oviposition on the less preferred host; however, when the host-choice experiment involved two varieties of the usual host, the response was faster than when the choice involved usual and unusual hosts. Finally, beetles reared on an unusual host （chickpea） for 26 generations showed similar good fitness on both usual and unusual hosts, indicating that the use of a new host does not necessarily result in the loss of performance on the original host. Nevertheless, this population showed lower fitness on the usual host than that of the original population, suggesting an underlying partial trade-off phenomenon which may contribute to a broadening of diet of this insect species.

关 键 词：artificial selection EVOLUTION PHASEOLUS CICER plant-insect interaction 

分 类 号：Q961[生物学—昆虫学]