2 REGIONAL STRAINS OF A PHORETIC EGG PARASITOID, TELENOMUS-EUPROCTIDIS (HYMENOPTERA, SCELIONIDAE), THAT USE DIFFERENT SEX-PHEROMONES OF 2 ALLOPATRIC TUSSOCK MOTH SPECIES AS KAIROMONES

The egg parasitoid, Telenomus euproctidis Wilcox (Hymenoptera: Scelion idae), is phoretic on females of two allopatrically distributed tussoc k moths, Euproctis pseudoconspersa (Strand) and Euproctis taiwana (Shi raki) (Lepidoptera: Lymantriidae). Crossing experiments between the tw o regional parasitoid strains indicated no evidence for their reproduc tive isolation. More wasps were found on the locally occurring host, E . pseudoconspersa, than on E. taiwana, when virgin females of the two moth species were exposed concurrently in the field for 24 hr in Ibara ki Japan. In Ibaraki, many wasps were caught in traps baited with the synthetic sex pheromone of E. pseudoconspersa, 10, 14-dimethylpentadec yl isobutyrate (10Me14Me-15:iBu), but none with that of E. taiwana, (Z )-16-methyl-9-heptadecenyl isobutyrate (16Me-Z9-17:iBu) or blank traps . In Okinawa, Japan, more wasps were found on E. taiwana than on E. ps eudoconspersa, and many wasps were caught in traps baited with 16Me-Z9 -17:iBu, but only a few with 10Me14Me-15:iBu, and none with blank trap s. These results suggest that local wasp strains discriminate between the two sex pheromones, and they strongly prefer the sex pheromone of the moth occurring at their location.