https://youtu.be/Mhogd39N7KM
The relationship between plants and pests can give us clues as to how to create new pesticides. Case in point, caterpillar poop could be used as a pesticide. Plants have sensors that can identify when the plant is in trouble and respond with defense mechanisms: for an example, the relationship between the corn plant and the armyworm larvae. The caterpillar feeds on corn leaves and the plants response is to release foul-tasting enzymes to discourage this pest from eating it, but somehow those defenses don’t work against the armyworm caterpillar. The caterpillar takes advantage of a weakness in the corn: Corn has two lines of defense, but it can only use one defense at a time: one against fungal infections and one against pests. So the caterpillar’s poops drops down into the corn plant near the stem, and actually trigger the plant to send out its fungal defenses. Thus the caterpillars are able to eat the leaves. Researchers are looking to isolate exactly which compounds in the poops trigger those fungal defenses and end up with a protection against fungal infections that comes straight from nature.
http://www.delta-optimist.com/opinion/blogs/deltabc-1.983313/blog-pesticide-from-caterpillar-poop-1.2058864