Abai, MR

6th International Congress of DipterologyDevelopmental velocity and the time of emergence in a dayfor Diadiplosis hirticornis (Diptera: Cecidomyiidae)attacking Planococcus kraunhiae (Homoptera:Pseudococcidae)Teshiba, M. (1) & T. Tsutsumi (1)(1) Fukuoka Agricultural Research Center, Chikushino, Fukuoka 818-8549, Japan A mealybug, Planococcus kraunhiae KuwanaHomoptera:Pseudococcidae is one of the most serious insect pests of persimmon inJapan. Frequently we have observed predatory larvae of Diadiplosishirticornis (Felt) Diptera: Cecidomyiidaefeeding on the mealybug. Toestablish control measures against the mealybug with D. hirticornis as abiological control agent, we need to gather basic information on theecological and behavioral attributes of D. hirticornis. As the first step, weinvestigated its developmental velocity at 20, 22.5, 25, 27.5, and 30 andthe time of emergence in a day.The developmental threshold for male andfemale was estimated to be 9.6 and 10.2 , respectively, andtemperature accumulation required for the development from egg to adultwas calculated to be 250 day-degrees. The time of emergence differedbetween sexes. The males emerged exclusively between 6:00 and 12:00 inthe morning, while most females emerged between 10:00 and 18:00.Key Words: Diadiplosis hirticornis, Planococcus kraunhiae, predator,developmental velocity, developmental threshold, day-degreeaccumulation, time of emergence∗∗∗∗∗∗∗∗∗∗264