Abstract

Till recently, success in termite control was mainly due to the use of highly persistent organochlorine insecticides such as aldrin. Because of environmental concerns use of organochlorines is now being phased out. The present study was undertaken inthe above context to evaluate less persistent insecticides and other ecofriendly products for control of termites attacking young plantations of eucalypts. Three small-scale and one large-scale field trials were carried out from 1993 to 1995. An organophosphate (chlorpyrifos), two synthetic pyrethroids (cypermethrin and fenvalerate), a plant product (neem cake) and a bacterial broth based on Rhizobacteria were evaluated. Chlorpyrifos was found to give the best protection by prophylactic application to soil in the polythene bag container (12 cm x 18 cm). Neem cake and the bacterial preparation were totally ineffective. Fenvalerate and cypermethrin gave varying degrees of protection at higher doses. Chlorpyrifos, at a dosage of 0.25g a.i. (active ingredient) per plant gave effective protection. However, a dosage of 0.5g a.i. per container is recommended for large-scale field application. A two ha area planted with E. tereticornis at the above dosage in Erumapetty (Wadakkancherry Range, Thrissur Forest Division) proved the efficacy of the treatment. Peak incidence of termite attack occurred during the first six months after planting out in all the trials and 20 to 70 per cent of the plants were killed in untreated control plots