REPRODUCTIVE-BIOLOGY AND BEHAVIOR OF A THELYTOCOUS SPECIES OF ERETMOCERUS (HYMENOPTERA, APHELINIDAE) PARASITIZING BEMISIA-ARGENTIFOLII (HOMOPTERA, ALEYRODIDAE)

Eretmocerus sp., a thelytokous aphelinid parasitoid of Bemisia argenti folii Bellows & Perring, was imported into the United States from Hong Kong in June 1992. We investigated the foraging behavior and reproduc tive biology of this species as part of an evaluation of its potential for biological control of B. argentifolii. Parasitoids performed ster eotyped behaviors upon encountering whitefly hosts, including antennat ion, circle-antennation, probing, postprobing host tapping, and host f eeding. During 1-h videorecording periods, parasitoids were observed t o accept all whitefly instars for host feeding and oviposition. After confining parasitoids for 24 h with whitefly nymphs, significantly mor e eggs were found under end and 3rd instars than under Ist and 4th ins tars. Parasitoids fed honey, with no access to whitefly nymphs, lived significantly longer (12.5 d) than those given access to nymphs, but n o honey (8.4 d). Lifetime fecundity averaged 92.8 female progeny per f emale, ranging from 3 to 147. Daily fecundity, measured as the number of whitefly nymphs parasitized per female each day for 9 d, averaged 2 0 for the first 6 d of life, and then declined to <10. On average, 4.5 nymphs were fed on by parasitoids each day during the first 3 d of li fe. Developmental period from oviposition to parasitoid emergence was significantly shorter in 3rd instars of tile host (16.4 d), than in 2n d (16.8 d) or Ist instars (17.6 d).