昆虫与植物的协同进化:寄主植物-铃夜蛾-寄生蜂相互作用

近数10年内,Ehrlich和Raven于1964年提出的协同进化理论及Jermy于1976年提出的顺序进化理论极大地促进了对昆虫与植物相互作用的研究。文章首先简要介绍有关理论,对植食性昆虫与植物关系研究的若干核心问题进行评述。主要问题包括(1)植食性昆虫如何选择寄主植物?(2)植物次生物质是否作为植物防御昆虫取食的重要屏障?(3)昆虫能否适应植物的化学防御?(4)植食性昆虫寄主范围是否是从广到专演化的?随之,作者结合对铃夜蛾Helicoverpa系统研究取得的结果,对上述问题做了进一步的论证和阐述。最后,在继承协同进化、顺序进化等理论精髓的基础上,根据当今三营养级相互作用领域的研究新进展,提出一个新的假说,即多营养级协同进化假说。该假说肯定植物次生物质在植物防御和昆虫识别寄主植物上的重要作用,同时把其他营养级并列放入交互作用的系统,特别强调第三营养级在昆虫与植物关系演化过程中的参与和寄主转移与昆虫食性专化和广化的联系。

Insect-plant co-evolution: multitrophic interactions concerning Herlicoverpa species

In the field of insect-plant interactions, the theory of co-evolution proposed by Ehrlich and Raven in 1964 and the theory of sequential evolution by Jermy in 1976 have stimulated many studies over recent decades. Concerning the two theories, several major questions are brought forward: (1) How insect herbivores select host plants? (2) Do secondary compounds protect plants from attacking of insect herbivores? (3) Do insect herbivores adapt to plant chemical defenses? (4) What pattern is the evolution of host range in insect herbivores, specialization or generalization? Focused on the above questions, the results in the studies of tritrophic interactions concerning Helicoverpa species were discussed. Based on the co-evolution and sequential evolution theories and the considerable advances made in tritrophic interactions recently, a new hypothesis called multitrophic co-evolution is proposed. The multitropic co-evolution hypothesis accepts that plant secondary compounds play an important role in chemical defense of plants and host selection of insect herbivores, but expands the interacting insect-plant system to the multitrophic system, in which the impact of the third trophic level and host shift on the evolution of insect host range are emphasized.