Chrysomelids and ants

Abstract

Chrysomelid beetles and many of their larvae feed on leaf surfaces, a very exposed and hazardous habitat. In many parts of the world, much of the canopy of trees and shrubs is dominated by predacious ants. Many of these extremely active and ferocious insects kill and carry back to their nests for food almost any other insects that they encounter. However, some insects manage to survive in these ant-dominated areas and, as a result obtain a number of benefits. These include a high level of protection from their other enemies and a habitat from which most other competing phytophagous insects have been removed. Chrysomelid beetles arc probably the most successful group of insects exploiting this habitat and. to do this, deploy a wide range of stratagems, both active and passive, to avoid being eaten by ants. Many of these defensive strategems protect chrysomelids from several other kinds of predators in addition to ants, including insectivores and birds. The relationship between chrysomelids and ants has developed in some species from active defence through armed neutrality to living as commensals within the nests of ants.