Epilachna borealis

(Image from Clemson University Department of Entomology, Cooperative Extension Service)

 

 

 

The squash beetle, a type of ladybird beetle, scientifically known as Epilachna borealis, is in the order Coleoptera and part of the Coccinellidae family. Adult ladybird beetles are often hemispherical in shape, less than 1.2 cm in length, with a distinctive orange or red colored body with black markings. Ladybird beetles, many of which are found in North America, make their home on plants with high populations of aphids, mites, and other plant-eating insects in temperate and tropical areas throughout the world. Most ladybird beetle species are carnivorous, which is beneficial to the protection of crops from agricultural pests. However, the Epilachna borealis feeds on the leaves of cucurbitaceous plants.

 

In a journal entitled, ìCombinatorial Chemistry in Insects: A Library of Defensive Macrocyclic Polyamines,î an experiment was conducted to analyze the chemical defenses of the ladybird beetle, Epilachna borealis. An entirely new family of chemical structures, characterized as alkanoic acid derivatives, was discovered as the working ingredients of the Epilachna borealis chemical defense system. Epilachna borealis pupae utilize an interesting chemical defense mechanism consisting of oily droplets at the tips of glandular hairs that coat the beetle. The oily secretion is especially deterrent against ants. The chemical composition of the secretion consists of ester and amide compound alkanoic acid derivatives, mainly macrocyclic polyamines.