Fellowes M D E, Kraaijeveld A R, Godfray H C J
NERC Centre for Population Biology, Imperial College at Silkwood Park, Ascot, Berkshire, SL5 7PY, United Kingdom.
Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire, SL5 7PY, United Kingdom.
Evolution. 1999 Jun;53(3):966-972. doi: 10.1111/j.1558-5646.1999.tb05391.x.
An increase in resistance to one natural enemy may result in no correlated change, a positive correlated change, or a negative correlated change in the ability of the host or prey to resist other natural enemies. The type of specificity is important in understanding the evolutionary response to natural enemies and was studied here in a Drosophila-paxasitoid system. Drosophila melanogaster lines selected for increased larval resistance to the endoparasitoid wasps Asobara tabida or Leptopilina boulardi were exposed to attack by A. tabida, L. boulardi and Leptopilina heterotoma at 15°C, 20°C, and 25°C. In general, encapsulation ability increased with temperature, with the exception of the lines selected against L. boulardi, which showed the opposite trend. Lines selected against L. boulardi showed large increases in resistance against all three parasitoid species, and showed similar levels of defense against A. tabida to the lines selected against that parasitoid. In contrast, lines selected against A. tabida showed a large increase in resistance to A. tabida and generally to L. heterotoma, but displayed only a small change in their ability to survive attack by L. boulardi. Such asymmetries in correlated responses to selection for increased resistance to natural enemies may influence host-parasitoid community structure.
对一种天敌抵抗力的增加可能导致宿主或猎物抵抗其他天敌的能力没有相关变化、正相关变化或负相关变化。特异性类型对于理解对天敌的进化反应很重要，本文在果蝇 - 寄生蜂系统中对此进行了研究。选择对内寄生蜂阿索巴寄蝇（Asobara tabida）或布氏细蜂（Leptopilina boulardi）幼虫抵抗力增强的黑腹果蝇品系，在15℃、20℃和25℃下暴露于阿索巴寄蝇、布氏细蜂和异腹细蜂（Leptopilina heterotoma）的攻击之下。一般来说，除了针对布氏细蜂选择的品系呈现相反趋势外，包囊化能力随温度升高而增强。针对布氏细蜂选择的品系对所有三种寄生蜂的抵抗力大幅增加，并且对阿索巴寄蝇的防御水平与针对该寄生蜂选择的品系相似。相比之下，针对阿索巴寄蝇选择的品系对阿索巴寄蝇以及通常对异腹细蜂的抵抗力大幅增加，但对布氏细蜂攻击的存活能力仅发生了微小变化。对天敌抵抗力增强的选择在相关反应中的这种不对称性可能会影响宿主 - 寄生蜂群落结构。
