Viruses require a host in order to multiply and become active. The wasp virus is induced by a parasitic wasp Dinocampus coccinellae. Also displaying parasitism a non-mutual symbiotic relationship between species where the parasite benefits at the expenses of its host. The host is needed to complete the lifecycle of the parasite. Since the parasite is using its hosts as a resource it is bound to cause the host to act differently.
The Dinocampus coccinellae turns female ladybugs into zombie babysitters. It lays its eggs inside the ladybug and injects a virus called D. coccinellae paralysis virus (DCPV). The wasp larva lies inside and bursts out about three weeks later and forms a cocoon between the legs of the ladybug. The virus leaves the ladybug alive but paralyzes it when the larva bursts out. The ladybug is used to ward off predators until the adult wasp emerges a week later. In Science News it explains that the reason the wasp can enslave the ladybug is due to the virus. The virus attacks the ladybugs brain. In National Geographic a biologist at Stony broke University Nolween Dheillly explains DCPV is the first known virus involved in behavioral manipulation that benefits another species. The ladybug is not only used to warn off predators but provides nutrition for the larva. While the larva is growing inside it eats the insides of the ladybug.
In the Science News, Dheilly and colleagues searched for what triggers the paralysis. They searched gene activity by sequencing RNA gene transcripts between the wasp larvae and ladybug. This led to the discovery of unfamiliar viral RNA in the brains of infected ladybugs not found in a healthy ladybug. This virus replicates and builds up in brains cells rapidly until just before the larva comes out the virus bursts open. The study also detected the virus only in the ladybug’s brain and is believed to infect the whole nervous system. Researchers suggest that the paralysis can be due to the immune system of the ladybug. The immune genes activates when the larva emerges and attacks the DCPV- infected cells. Thus causing self- inflicted brain damage that temporarily paralyzes the ladybug just when the larva needs protection. The virus not only causes paralysis but tremors as well, this brain damage could be the cause of the defensive behavior the ladybug exhibits. There is still more research to be done on DCPV to prove if it is the cause of turning ladybugs into zombie babysitters. The relationship between parasites and hosts is crucial to understand because there could be other factors involved like the origin of virus and its connection to this relationship. There are still a lot of questions that remain unanswered and studies are still ongoing.
Posted by Jazmin Granadeno (Group B)