Abstract

The poor growth performance of Ailanthus triphysa in forest plantations in Kerala is generally attributed to infestation by the leaf and shoot webber, Atteva fabriciella. To study the insect impact, a group of 100 trees in a 6-year-old A. triphysa plantation was protected against A. fabriciella during 1988-1990, by monthly spraying of insecticide. In two other sets of trees, insecticide was sprayed at 3 month and 6 month intervals and a fourth set formed the untreated control. Height and GBH were recorded at 6-month intervals for 2 years. Increase in height and basal area under different treatments showed that protecting the plants against A. fabriciella attack resulted in increased growth. The insect also damaged the inflorescence and tender fruits, thereby affecting seed production in A. triphysa