Role of Biocontrol Agents for the Pest Management in Mulberry (morus Spp.) Cultivation

Mulberry (Morus spp.) is the only food plant for the silkworm, Bombyx mori Linn., which is an economically important insect for sericulture industry. Mulberry is attacked by a number of insect pests, parasites, predators and pathogens around the year which not only affect the leaf quality but also responsible for poor yield. Mulberry is reported to be attacked by more than 200 species of insects belonging to various orders. Pests are of major significance for mulberry cultivation for foliage production. According to an estimate, the pests and diseases cause about 25% loss in foliage production of mulberry, besides deteriorating the nutritive value of leaves. Although several chemical pesticides have been suggested for the control of pests in mulberry these chemicals cannot be relied upon all the times due to their residual toxicity. Furthermore, since the chemical have to be applied repeatedly for the consistent pests and disease control, their unscientific usage can be hazardous to silkworm crop, besides polluting the environment and killing the beneficial microflora and fauna of the mulberry rhizosphere. Realizing the drawback of chemical measures of pest control, the usage of biocontrol agents has received maximum attention for the control of mulberry pests. The insect populations are naturally affected by a wide variety of environmental factors, both biotic and abiotic. The action of these factors is often termed natural control. One aspect of natural control is biological control, which involves the regulation of population of pests by the use of biotic agents. Biological control agents traditionally have been considered to be predators, parasitoids and microbial pathogens. Mulberry is subjected to damage by various species of sap suckers and defoliating insects. Among sap suckers mealybug, thrips, jassids, scale insect and white fly caused appreciable damage and play an important role in decreasing the crop yield significantly. The two major groups of defoliators that cause damage to mulberry leaves via their chewing mouthparts include the caterpillars and beetles. The present review focuses on the insect pests of mulberry and their management by using biocontrol agents in mulberry plantation.