Population model for Ascotis selenaria (Lepidoptera: Geometridae) in citrus orchard

Egg, larva, and pupa developmental rate (1/median day) were incorporated into temperature-dependant developmental rate models, respectively, using Hilbert & Logan model. Weibull function was applied to describe their developmental complete distribution based on the summation of their daily developmental rate. Adult oviposition model consists of a total fecundity model, an age-specific cumulative oviposition model, and an age-specific survival model, in which physiological age was calculated from adult developmental rate model. A Gaussian model was applied to the total fecundity model and a sigmoid function was to an adult developmental rate model. A normalized cumulative oviposition rate and a survival rate with physiological age were incorporated into those age-specific models. A population model for A. selenaria was established by linking egg, larval, pupal, and oviposition models. Survival rate of pupae and adult was set to 0.8. Larval survival rate, considering natural enemies and etc., was set to 0.1. It was speculated from the field examination that hatched larva were drift from oviposition site to citrus. therefore egg survival rate was set to 0.02 for simulation. Each Model outputs were compared with the actual 1st larva and adult occurrence surveyed in a citrus orchard in Seogwipo, Jeju from 2008 to 2010. A simulated output driven in the case that overwintered pupae were grouped with different developmental rates was successfully fit to actual 1st larva and adult occurrence and the peak time. Recently test version of ‘Popmodel’ program, a builder and simulator for insect model, was developed by author. One of the function of the program can use a series of data as start condition for simulation. So a series of data of the first occurrence of adult in 2009 and 2010, estimated by simulating the population model with the temperature data from 2007, were used as the start condition to simulate the daily alive density of each stage in 2009 and 2010, respectively. Consequently those estimated data were fit well to the actual field catches of the adult and larvae.