Abstract

Seasonal incidence was studied by visual scoring of the defoliation at fortnightly intervals throughout the year. During the 5-yr period from 1978 to 1982, measurable defoliation occurred only in two years - 1980 and 1981. It was confined to the later part of the growing season from Nov. to Jan.during this period, the intensity of defoliation ranged from 14 to 40, with the exception of Nov. 1981 when near total defoliation occurred in one of the two study blocks. Small numbers of larvae were present almost throughout the year, with a small peak in May-June which did not lead to measurable defoliation. Earlier observations showed that in Nov. 1976 a heavy and widespread outbreak of E. machaeralis occurred in teak plantations throughout Kerala. Itis concluded that late season outbreaks of E. machaeralis are an occasional but not regular phenomenon in teak plantations in Kerala and that outbreaks may be particularly heavy and widespread in exceptional years