Response of life-history traits to artificial and natural selection for virulence and nonvirulence in a Drosophila parastitoid, Asobara tabida

• 来源期刊: 中国昆虫科学（英文版）
• 关键词: encapsulation geographic variation host resistance trade-offs
• 年，卷（期）: 2018,（2）
• 页码范围: 317-327
• 页数: 11页
• 语种: 英文
• DOI: 10.1111/1744-7917.12428

摘要

Co-evolution of host-parasitoid interactions is determined by the costs of host resistance,which received empirical evidence,and the costs ofparasitoid virulence,which have been mostly hypothesized.Asobara tabida is a parasitoid,which mainly parasitizes Drosophila melanogaster and D.subobscura,the first species being able to resist to the parasitoid development while the second species is not.To parasitize resistant hosts,including D.melanogaster,A.tabida develops sticky eggs,which prevent encapsulation,but this virulence mechanism may be costly.Interindividual and interpopulation variation in the proportion of sticky eggs respectively allowed us to (i) artificially select and compare life-history traits of a virulent and a nonvirulent laboratory strain,and (ii) compare a virulent and a nonvirulent field strain,to investigate the hypothetical costs of virulence.We observed strong differences between the 2 laboratory strains.The nonvirulent strain invested fewer resources in reproduction and walked less than the virulent one but lived longer.Concerning the field strains,we observed that the nonvirulent strain had larger wings while the virulent one walked more and faster.All together,our results suggest that virulence may not always be costly,but rather that different life histories associated with different levels of virulence may coexist at both intra-and interpopulation levels.