🚨 ARTHROPOD OF THE DAY 🚨

Braconid wasps are Mother Nature's way of keeping pests like hornworms under control. These parasitic wasps disrupt their host insect's development, effectively stopping the pest in its tracks. Braconid wasps are parasitoids, meaning they eventually kill their hosts.

Although we're probably most familiar with the larger braconid wasps that live on hornworms, there are actually thousands of braconid wasp species throughout the world, each infecting and killing certain types of host insects. There are braconids that kill aphids, braconids that kill beetles, braconids that kill flies, and of course, braconids that kill moths and butterflies.

Braconid wasps use a remarkable weapon to disable the defenses of their host insects – a virus. These parasitic wasps coevolved with polydnaviruses, which they carry and inject into the host insects along with their eggs. The polydnaviruses have no negative affects on the braconid wasps, and reside within cells in the wasp ovary.

When the braconid wasp deposits eggs in a host insect, she also injects the polydnavirus. The virus is activated in the host insect, and immediately goes to work disabling the host's defenses against intruders (the intruders being the braconid wasp eggs). Without the virus running interference, the wasp eggs would quickly be destroyed by the host insect's immune response. The polydnavirus allows the wasp eggs to survive, and the wasp larvae to hatch and begin feeding inside the host insect.