Biocoenology and control of whiteflies in sericulture

Abstract The damage caused by the whiteflies Dialeuropora decempuncta (Quaintance & Baker, 1913), Aleurodicus dispersus Russell, and Aleuroclava sp. to mulberry plants is extensive and they cause a huge economic loss to mulberry leaves which affects silkworm rearing. Dialeuropora decempuncta is a major pest in western Bengal, whereas spiralling whitefly A. dispersus has been reported to attack mulberry plants in South India. The whiteflies are present throughout the year in south India, with high populations in summer (March—June) and low ones in winter (October—January). The population is positively correlated with temperature and negatively correlated with humidity. Chemical control is the quick solution to minimize the pest population. However, the indiscriminate and large-scale use of highly poisonous synthetic chemical pesticides has resulted in ecological imbalance, in addition to their toxic effects on living organisms, including human beings. Hence there is a need for developing methods and materials within an eco-friendly atmosphere. Previous investigations indicate that neem-based insecticides may be a suitable alternative for pest management in sericulture. Use of neem products in sericultural pest control has many merits. It will also help in the successful introduction of biological controls in India. Several exotic parasitoids have been found to be highly effective, including two aphelinid parasitoids Encarsia haitiensis Dozier and E. meritoria Gahan. These are most promising and are reported to minimize the fly pest population. The parasitization potential and behaviour of the parasitoids have to be carefully assessed before they are introduced to control fly pest populations. There is a need for careful assessment of all these advanced biological technologies in order to develop a profitable, safe and durable approach for whitefly control in sericulture.