瓢虫充当马蜂幼虫的“免费保姆”

Are ladybugs（瓢虫） being overtaken by wasps²? A Université de Montréal entomologist（昆虫学者） is investigating a type of wasp¹（黄蜂，胡蜂） (Dinocampus coccinellae) present in Quebec that forces ladybugs (Coccinella maculata) to carry their larvae³（幼虫）. These wasps lay their eggs on the ladybug's body, a common practice in the insect world, yet they don't kill their host. "What is fascinating is that the ladybug is partially⁴ paralyzed（瘫痪的） by the parasite⁵（寄生虫，食客）, yet it's eventually released unscathed（未受伤的）," says Brodeur, who is also a biology professor and Canada Research Chair in Biocontrol. "Once liberated⁶, the ladybug can continue to eat and reproduce as if nothing happened."

A larva cocoons⁷（茧） between the ladybug's legs and moves on once it matures. Brodeur is currently studying the phenomenon at the Université de Montréal Institut de recherche⁸ en biologie végétale. He hopes to understand the cycle duration, success rate and the host-parasite relationship.

"Can the ladybug refuse to be used? We don't know. Our plan is to reproduce a variety of situations in the lab and see which is most favourable⁹ to reproduction," he says.

Wasps aren't alone in offloading their offspring, stresses Brodeur, since magpies¹⁰（喜鹊） look after the chicks of great spotted¹¹ cuckoos（杜鹃，布谷鸟）. The cuckoo visits the nests where it leaves its young and kills those magpies that don't protect their offspring. And a variety of parasite behaviours exist in the insect world, yet the dynamic（动态的） between the Dinocampus coccinellae and Coccinella maculata（有瑕疵的，有斑点的） is unusual and one Brodeur hopes to better understand.