Author : Vichian Hengsawad

Summary : The study attempted to evaluate the effects of different degrees of canopy pollarding of Gliciridia on the incidence, abundance, and injury of the bean lycaenid, Catochrysops cnejus F. on intercopped pegion pea. The insect's life cycle was studied in the laboratory and results showed the egg, larval, pupal, and adult periods to last for 2-4 days, 10-16 days, 6-10 days, and 2-3 days, respectively. The incidence and abundance of the insect were determined by direct counts of the number of eggs, larvae and pupae from the collected samples. Adult population densities were determined by visual observations in the field. Injury on pigeon peas was determined by the infestation rate of the insect on flowers, pods and seeds, and weight losses of immature pods and mature seeds. Both incidence and injury of the insect were inversely related with the diameter pf Gliricidia canopy, that is, the greater the diameter of Gliricidia canopy, the lower were the incidence, abundance and injury from the insect. On the other hand, the incidence, abundance and injury caused by the bean lycaenid increased with greater degree of wxposure of pigeon pea to the insect. The confusing visual and olfactory stimuli received from host and non-host may disrupt normal behavior of host findings of the insect. The yield component, as expressed in number of pods and seeds per plant and the total seed weight, did not show any significant differences among treatments. In general, greater infestations were found in pure stands than in mixed croppings of pigeon pea, but these were compensated with high flower production and greater number of seed per pod.