Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 12 2 2010 04 01 Biology of Chrysocharis pentheus, an Endoparasitoid Wasp of the Citrus Leafminer Phyllocnistis citrella Stainton 145 154 15313 EN Sh. Mafi Agricultural and Natural Resources Research Center of Mazandaran, P. O. Box: 48175-556, Sari, Islamic Republic of Iran. N. Ohbayashi Entomological Laboratory, Faculty of Agriculture, Ehime University; Matsuyama 790-8566, Japan. Journal Article The biology of Chrysocharis pentheus (Walker) (Hymenoptera: Eulophidae), the most abundant endoparasitoid of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Ehime prefecture, Japan, was studied under laboratory and field conditions. The mean immature developmental time and adult longevity at different temperatures (22 to 31°C) under 50-70% RH decreased as the temperature increased, and females survived longer than males. The developmental threshold of male and female was 8.9°C and 11.9°C, respectively. The effective accumulative temperature (thermal constant) for males and females from egg to adult was 181.8 and 238.1 degree-days, respectively. C. pentheus appeared to be a synovigenic species. The offspring sex ratio from females provided with males was 73.8% males and 26.2% females. Presumably, mated females began oviposition 1-2 days after emergence and continued for up to 40 days. Females laid a mean of 118.2±10.10 eggs each, and their longevity reached 32.3±0.30 days at 27±1°C, 50-70% RH. The intrinsic rate of natural increase (rm) was 0.144. Host feeding or stinging without oviposition killed 65.7±8.65 P. citrella larvae per female. Oviposition in the field was highest (62.7%) on the third instar larva of P. citrella, with the rest on the prepupal stage (37.3%), showing a significant preference for third instars. The sex ratio (M:F) of C. pentheus reared from the third instar larvae of host and pupae was 3.3:1.0 and 1.0:3.0 respectively. https://jast.modares.ac.ir/article_15313_43303a6b28a9ac364c40baec04aa5559.pdf