THE EFFECTIVENESS OF <em>TOONA</em> <em>SINENSIS</em> (MELIACEAE) AS INSECT REPELLENT

Abstract

An experiment was conducted over a period of six weeks, to observe the effectiveness of Toona sinensis as insect repellent. Three other tree species from the same family (Meliaceae), namely, Toona sureni, Chukrasia tabularis and Swietenia macrophylla.: were used as test plants, as most meliaceous trees are susceptible to attacks by shoot borers. The percentage of leaf damage of test plants at six different distances from Toona sinensis was used as a measure of effectiveness of the latter in repelling insect pests. It was found that Toona sinensis was effective in controlling pest attacks, the more so the nearer this species was to the test plants. Swietenia macrophylla was least susceptible to pest attacks, Chukrasia tabularis, more susceptible and Toona sureni, the most susceptible. Toona sinensis placed among a mixture of the three test plants was effective in controlling pest attacks.