Trade-offs in the host selection by phloeophagous parasitic insects on conifers

昆虫和植物已经共存了数亿年，经常进化出密切的联系，甚至相互依赖。植物和昆虫之间最常见的相互作用涉及昆虫利用植物组织作为食物和/或繁殖资源，常常使昆虫与人类利益直接冲突。为了应对昆虫在木材中取食或繁殖所施加的选择压力，大多数木本植物都进化出了一种有效的防御化学物质。大多数种类的昆虫只能忍受有限的暴露于这些化学品，因此只能在死亡的宿主中进食和繁殖，但有限数量的物种可以利用活组织，或者在宿主死亡时入侵，杀死它，或者在少数情况下作为寄生虫生活。寄生昆虫对理解昆虫选择宿主的线索很感兴趣，这是我们仍然不太了解的。

Insects and plants have co-existed for hundreds of millions of years, often evolving close associations and even co-dependence. The most common interaction between plants and insects involve the utilization of plant tissue as a food and/or breeding resource by insects, often placing insects in direct conflict with human interests. In response to the selective pressures exerted by insects feeding or breeding in wood, most woody plants have evolved a potent cocktail of defensive chemicals. Most species of insects can tolerate only limited exposure to such chemicals, and hence feed and breed only in dead hosts, but a limited number of species can utilize live tissue, either invading it as the host is dying, killing it, or in a few cases living as a parasite. The parasitic insects are of interest in understanding the cues that insects use in selecting a host, something we still don't understand very well.