볼록총채벌레 월동성충의 산란모형 및 포장적합

Abstract

Yellow tea thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), is regarded as a key pest on citrus fruits in tropical orsubtropical regions in South-East Asia, and is estimated to be increased by global worming. In Jeju Korea, the damage of this pest is expected to increase as subtropical weather condition is intensified in the future. Thus, this study was conducted to construct an oviposition model of overwintered S. dorsalis for the population model. The fecundity and longevity of overwintered S. dorsalis were examined at constant temperatures in the laboratory, and also population abundances were surveyed in the ields. Overwintered S. dorsalis adults showed activity during early to late April. New adults (the 1st generation) were observed from early May to late May followed by the 2nd generation adults in June, and thereafter generations were largely overlapped. Egg populations from overwintered females occurred between early April and mid May with peak occurrencein early May. The first larval instars were fist observed in late April, and they occurred until mid May. The results of ovipostion experiment for S. dorsalis indicated that the temperature affected adult longevity, survival, and fecundity. Overall, the longevity decreased as the temperature increased and the female adult developmental rates (1/median longevity) were well described by Erying model, and were used to calculate the adult physiological age. The lower threshold temperature for female adults of S. dorsalis was estimated 9.4℃. Total fecundity was the highest at 21℃, and then declined steadily thereafter. The relationship between total fecundity and temperature was well described by a nonlinear quation. The cumulative age-specific oviposition rate was well described by the 2-parameter Weibull function. The overall adult survival exhibited a reverse logistic curve. Threetemperature-dependent components, total fecundity, age-specific ovipositionrate, and age-specific survival rate, were incorporated into the oviposition model. Also, stage transition model of eggs was developed using the development rate model and distribution model of the development time of eggs. The oviposition model incorporated with the egg transition model. was simulated to predict egg population. Oviposition model simulation well described the field occurrence patterns of S. dorsalis egg population. However, model outputs predict the actual egg population with a 4d delay. The sensitivity analysis of model outputs was conducted by changing the physiological age of overwintered S. dorsalis females between 0.0 and 0.4. The results showed that fitting ability of the model outputs increased when the physiological age was subjected between 1.0 and 2.0. With a compensatory initial physiological age of 0.1645, the oviposition model could predict reasonably the egg laying time of overwintered S. dorsalis. Consequently, the present model should be useful for spraying time targeting on the 1st larval population in grapevines and green tea farms in early season, as well as for constructing population model of S. dorsalis.