POSSIBILITY OF USING LIGHT TRAP TO ESTIMATE THE POPULATION OF THE TEAK DEFOLIATORS

Abstract

Estimation of the population density of the teak defoliators by using light traps at Khaobin Teak Forest in Ratchaburi province in 1986 found the number of Hyblaea puera Cramer was much less than Eutectona machaeralis Walker. The average number of E. machaeralis caught daily from the light traps in June, July, August, and September was 14.3. 2.6, 1.2, and 0.2, respectively. In 1986, there was no outbreak of either H. puera or E. machaeralis at Khaobin Teak Forest, therefore the maximum number of moths caught per trap cannot be used as an index to indicate the outbreak. However, the number of moths of E. machaeralis caught from light traps showed some relation to the incidence of insect feeding in the study area. The result indicated that light trap was possible to use as one of the tools to estimate the population of E. machaeralis but not applicable to H. puera in the year of 1986.