One day I happened to notice what I thought was a green tomato that looked like it had a fungus on it. I was in a hurry to get inside and I did not carefully examine the tomato, I just made a note to myself to tell Greg about it when he got home.
That evening Greg called me from outside. He said I had to come see this.
What I thought was a tomato was in fact a dreaded hornworm caterpillar. What I mistook for fungus was actually little rice like pods hanging off its body.
Immediately we began to research. What looked like grains of rice are actually the cocoons of the braconid wasp, which lays its eggs under the skin of the caterpillar. The pupae emerge and spin the cocoon and several days later emerge as wasps.
While injecting its eggs, the wasp also injects the caterpillar with a neurotoxin so that it stops eating and basically just hangs out letting the larvae mature on its fluids.
I posted all this on my Instagram account real time. I had some great conversations with people wanting to know if the caterpillar was hurting (according to my research it is not, but how can one ever really know?) and wondering why I just did not pluck the caterpillar from the plant and kill it.
I was hoping that the video would be larger. Watch the upper right side of the caterpillar.
A wasp slowly emerges.
Once the caterpillar is infected, it is rendered harmless to the tomato plant. The wasps are actually beneficial insects. The wasps eat aphids and as they host on hornworm caterpillars, they keep their population down. By letting the wasps hatch, the continuation of the braconid population is advanced, and I have organic pest control!