Impact of spider mite feeding on vegetable crops

Agriculture plays an important role to determine the economy of Kerala. Being primarily an agriculturalstate, contribution of Kerala to the vegetable crop industry is a crucial one. However, despite the rich diversity ofour vegetable crops, knowledge on their faunal composition, particularly of spider mites as pests and other relateddetails remains very much limited. In recent years due to random use of chlorinated hydrocarbons for control ofgeneral pests, which in turn kill their natural enemies, and because of using high yielding varieties and improvedagricultural practices, many mite species which were of less importance or of no value at all during the past haveassumed the status of major pests. These, among other factors have further aggravated the situation of the problemof spider mites as pests.The plant feeding mites (Acari: Tetranychidae) has piercing and sucking type of mouth parts with whichit pierces the leaf tissue and sucks the plant sap. The point of suction is marked by the appearance of white spotswhich gradually coalesce to form chlorotic patches, necrotic patches etc. Spider mite feeding cause various typesof direct damage like loss of chlorophyll, appearance of striplings or bronzing of foliage, stunting of growth,formation of galls and erineal patches thereby causing an array of deformities and reduction of yield. The intensityof damage ranging from simple mechanical injury to complex physiological alterations of the plant tissues wouldlead to collapse of the photosynthetic machinery of the plant. Apart from direct damages, many are known to actas vectors of plant viral diseases causing more potential loss to growers. In many instances, lack of informationabout the correct identity of spider mites, their biology and ecology caused serious consequences to agriculture.In view of their importance in agriculture, the present study is thought to be highly warranted, as it isenvisaged with a view to provide information on the impact of feeding of the spider mites