Bioecology of Arthroschista hilaralis (Lepidoptera: Pyralidae) on Jabon (Anthocephalus cadamba Miq.).

Abstract

Arthroschista hilaralis is a defoliator of Anthocephalus cadamba with a high level of damage. The information about bioecology of A. hilaralis is needed to determine the appropriate pest management strategies. The aim of this study is to review the biology (life cycle and life table) and ecology of A. hilaralis (attack of A. hilaralis on jabon in different plantation age and altitude). The study of life cycle was conducted by observing the development of life stage A. hilaralis, such as time of life cycle and body size. The study of life table was conducted by calculating the mortality of A. hilaralis individual and the number of offspring hatched by individuals at each age. There are some terms used to calculated the parameters of population growth like gross reproductive rate (GRR), net reproductive rate (Ro), mean generation time (T), individual per female per day (r). The ecology research of A. hilaralis has been done by observing attacks of A. hilaralis on jabon stands at the planting age 0.5; 1.0 and 1.5 years, as well as in the jabon stands in the lowlands and highlands, then calculate the percentage of damage level (K) and pest incidence level (IS) of A. hilaralis. The results show that life cycle of A. hilaralis is about 25.1 days, while egg stadium is 2.7 days, larvae 12.6 days, pupae 6.9 days and praoviposisi of adult 2.9 days. Life table of A. hilaralis show that GRR of A. hilaralis on jabon is 141 individual per generation, Ro revealed 70 individual per female per generation, T is 23.5 days, and the innate capacity for increase (r) 0.18 individual per female per day. Periodic pest management is needed in the development of pest control, due to the high level of development and the rapid rate of growth of A. hilaralis. Percentage of damage level of A. hilaralis on jabon at the planting age of 0.5, 1, and 1.5 is not significantly different, whereas pest insidence level of A. hilaralis at planting age 1.5 years was significantly different than the planting ages 0.5 and 1 year. Percentage of damage level and pest incidence level of A. hilaralis on Jabon stands in the lowlands and highlands showed no pronounce differences. This mean that the A. hilaralis are cosmopolitan, therefore pest management actions A. hilaralis needs to be done on both jabon stands in lowland and upland, and not just at the beginning of planting but also when standing jabon have grown old. The parasitoid in A. hilaralis are Phanerotoma sp., Chelonus sp., Apenteles sp., Tetrastichus sp., dan Ooencyrtus sp.