Managing termite menace in crops
Even though termites are of great economic importance and distributed widely, very little information is available on different species of termites in India. It is reported that 190 species of termites are there attacking a wide variety of crops like cereals, annuals, shrubs, living trees and timber.
Although termites are strictly tropical insects they invade the sub-tropics and to a limited extent, the temperate zone. The insects attack several agricultural and horticultural crops. It is estimated that the loss accumulated due to damage in these crops may run to several millions of rupees per year.
The important termite species invading different crops includes Odontotermes obesus, O. wallonensis and Microtermes obesi. Among them Odontotermes obesus is an important termite species which infests wheat, barley, sorghum, cotton, sugarcane, groundnut, coconut, sunhemp, chillies, mango, citrus, grapevine, peach, O. wallonensis is a major pest on maize, finger millet, redgram, sugarcane, groundnut, niger, castor, coconut, mango, jackfruit and cashew.
Microtermes obesi attacks several crops like wheat, barley, oats, maize, pearlmillet, pulses, cotton, jute, sugarcane, groundnut, coconut, sunhemp, chillies, vegetables, plantation crops, potato, cassava, chrysanthemum, rose and fruit trees.
— Deep ploughing or hand tillage exposes termites to desiccation and to predators, thus reducing their number.
— Pre-planting tillage also destroys the tunnels caused by termites and minimises their foraging activities and associated damage.
— Complete destruction of mounds and removal of queen termites are effective control measures against mound building species.
—Partial destruction of mounds is unlikely to solve problem if nymphs are present during the time of dequeening because replacement reproduction may develop.
— High density sowing, followed by thinning of surviving plants reduces anticipated losses due to termites.
(Dr. D. N. Kambrekar is Scientist,Agricultural Entomology, Regional Agricultural Research Station, University of Agricultural Sciences, Bijapur-Karnataka, Email: kambrekardn @gmail. com: Phone: 08352 230568)