An outbreak and some notes of the noctuid Achaea janata L., on Excoecaria agallocha L. in Hutan Melintang, Perak.
An outbreak of larvae of Achaea janata (L.) occurred on the wild euphorbiaceous plant Excoecaria agallocha adjacent to an estate of cacao and coconut in Perak, Malaysia, in May-June 1982. Because of the danger of infestation of the crops, the biology and control of the noctuid were investigated. The eggs were laid singly or in clusters on the leaves and stems of the food-plant and hatched in about 4 days. Pupation took place in a loose cocoon in the soil, between leaves spun together, or in bark crevices or other sheltered spots, and the pupal stage lasted about 10 days. The total life-cycle was estimated to be over 1 month. In no-choice preference tests, E. agallocha was the preferred food-plant, but leaves of cacao and stamens and pistils of coconut were also chewed. The parasites Microgaster maculipennis (Szepl.) (Microplitis maculipennis), Charops bicolor (Szepl.), Echthromorpha agrestoria (Swed.), Brachymeria tarsalis Motsch. and Exorista sorbillans (Wied.) (Thrycholyga sorbillans) were recorded. B. tarsalis was a hyperparasite, attacking C. bicolor. In insecticidal screening tests, permethrin (Ambush) and deltamethrin (Decis) gave quick knockdown of the noctuid larvae, and trichlorphon (Dipterex) and monocrotophos (Azodrin) were promising.