دانلود گزارش کارورزی و کار آموزی

a b s t r a c t : 

Parasites have evolved various strategies to exploit hosts to their own advantage. Bodyguard manipu-lations consist of usurping the behaviour of the host to confer some protection to the parasite and/orits offspring. Dinocampus coccinellae Schrank is a solitary endoparasitoid of the spotted lady beetleColeomegilla maculata lengi Timberlake. The parasitoid larva grows inside the host until mature, thenegresses and spins a cocoon between the ladybird’s legs. Unlike most parasitoids, D. coccinellae does notkill its host during development, but keeps the coccinellid partially paralysed on top of the cocoon, whereit acts as a bodyguard against natural enemies. As recently shown, the presence of a living ladybird on theparasitoid cocoon provides efficient protection against a predator, lacewing larvae. In the present study,we used predators with different foraging behaviours—jumping spiders and crickets—to explore the rel-evance of the bodyguard strategy for D. coccinellae in a multipredator context. Although the manner ofthe protection differs among the different tested predators, the presence of the ladybird always enhancesparasitoid survival, even when it first increases detection of the cocoon–ladybird complex, as is the casewith jumping spiders. Furthermore, although a dead bodyguard is sufficient to passively defend para-sitoid cocoons against crickets, it provides only partial protection against jumping spiders. Altogether,these results support the bodyguard hypothesis in a multipredator context, since the presence of a liv-ing coccinellid significantly reduces cocoon predation by predators having different prey specificities,morphologies, and hunting behaviours.