Caterpillars of the Monarch Butterfly feed on plants in the milkweed family that contain toxins called cardenolides. The caterpillars sequester the toxins from the plant. The toxins are stored in the tissues and protect the adult Monarch Butterflies from predation by birds.
Cardenolides protect the caterpillars from some predators (but not others). I have personally observed brown stink bugs preying on Monarch Caterpillars. Another insect that can successfully prey on Monarch Caterpillars is the Chinese Mantid. Rafter and Colleagues* observed Chinese Mantids (Tenodera sinensis) feeding on Monarch Caterpillars using a “toxin avoidance” technique. Chinese Mantids will consume the entire tissue, including the guts, of corn borer and wax moth caterpillars. When feeding on Monarch Caterpillars, Chinese Mantids do not consume the gut but consume all other tissue.
Rafter and colleagues investigated the distribution of cardenolides in the caterpillars and found that the body and gut had similar quantities…
View original post 106 more words