Vol. 1, Issue 2 (2016)
Recognition of some lady beetles (Coleoptera: Coccinellidae) deadly sighted for insect and mite pests in agroecosystems
Author(s): Muhammad Sarwar
Abstract: In the present article, an attempt is made to interpret the identification of ladybeetles (Coleoptera: Coccinellidae), their ecology, preys and inferences drawn by discussing the role they play in agroecosystems. Predaceous ladybeetles have largely fascinated to ecologists of the world over, because of their biocontrol potential against aphids, diaspids, coccids, aleyrodids and other soft-bodied insects and mites. Lady beetles are easily recognized by their shiny, convex, half-dome shape and short clubbed antennae. Most lady beetles species are predaceous as both larvae and adults, whereas the young larvae usually pierce and suck the contents from their prey. Older larvae and adults chew and consume their entire prey, and both prey on soft-bodied pests such as aphids, mites and scales. One larva can consume hundreds of prey during its development, and owing to their voracious appetites and ability to multiply rapidly, lady beetles can control even large infestations of pests. They are important predators of orchard pests, and the two most common species are the convergent and transverse lady beetles. Adults and larvae of both these beetles feed primarily on aphids and occasionally on whiteflies, other soft-bodied insects and insect eggs. Multicolored Asian lady beetle Harmonia axyridis, can establish itself extensively, and since it feeds on many species of soft-bodied insects, including aphids, scales and psyllids, this beneficial insect is considered to be a very good friend to gardeners. Both adults and larvae of Harmoniaconvergens feed primarily on aphids and occasionally on whiteflies, other soft-bodied insects and insect eggs, and a very few species eat fungal spores. A few lady beetles eat pollen; especially early in the spring when there are not so many aphids to eat. The beating tray is the most widely used method of monitoring lady beetle adults, but densities of larvae and pupae can be estimated while making visual counts of pest populations. Avoid using broad-spectrum insecticides on plants that are toxic to lady beetles. Supplies of adults can be bought for release in orchards but they often disperse when aphid populations are low. Releases of lady beetles in the orchard in mid or late summer are unlikely to be very beneficial.