Reproductive Biology of Biosteres arisanus (Sonan), an Egg Larval Parasitoid of the Oriental Fruit Fly

Abstract

Abstract Biosteres arisanus (Sonan) is an internal egg-larval parasitoid candidate for biological control programs directed against several fruit fly pests of the family Tephritidae. To facilitate development of mass production methods, basic biological data pertaining to the reproductive activity of B. arisanus were collected. Daily progeny production for the cohort-age interval 6-20 days was found to be optimum, and a discard age of 21 days is recommended. The overall mean progeny production per day (50.4 ± 4.2 parasitoids) was doubled to 105.4 ± 23.2 when parasitoids were increased from 50 to 100 ♀♀/cage. In parasitoid cages of 200 ♀♀, mean progeny production per day peaked at 297.1 ± 43.8 parasitoids at age interval 6-10 days. Mean progeny yield/cage was 1309, 2433, and 3401 parasitoids when the initial cohort density was 50, 100, and 200 ♀♀, respectively. An oviposition exposure period of 6 h was optimum to minimize rates of host mortality or superparasitism. Unparasitized host puparia of Bactrocera dorsalis (Hendel) from parasitoid exposure cages can be efficiently separated by the size of host puparia. Up to 99.5% of the total B. arisanus emerged from pupal size class 1 (maximum width = 1.7 mm, maximum length = 4.1 mm) to size class 4 (maximum width = 2.1 mm, maximum length = 4.9 mm). Most of the unparasitized adult flies (80.6%) emerged from pupal sizes larger than size class 4. Furthermore, 97.6% of B. arisanus that emerged from size class 1 were males. Percentages of male parasitoid progeny declined significantly as the host puparial size increased (≍ 3% ♂♂ emerged from class 4 and 5 puparia).