APHID FECUNDITY, REPRODUCTIVE LONGEVITY, AND PARASITE DEVELOPMENT IN THE SCHIZAPHIS GRAMINUM (RONDANI)(HOMOPTERA: APHIDIDAE) – LYSIPHLEBUS TESTACEIPES (CRESSON) (HYMENOPTERA: BRACONIDAE) SYSTEM

Abstract

AbstractThe fecundity and reproductive longevity of Schizaphis graminum (Rondani) parasitized by Lysiphlebus testaceipes (Cresson) were determined in the laboratory under four temperature regimes. Daily reproduction by S. graminum declined rapidly after parasitization except at a relatively low temperature regime (12–16 °C). The mean progeny production by parasitized aphids of 2.75 ± 0.08 nymphs per parasitized adult was not significantly different than that for unparasitized aphids (2.94 ± 0.23 nymphs) during the period of time equal to the reproductive life of parasitized aphids. Reproductive longevity of parasitized aphids was longest at the lowest temperature (5.67 ± 0.25 days at 12–16 °C). No significant differences were observed in total progeny produced at different temperatures. The number of progeny within parasitized nulliparous adults (3.37 ± 0.33) as determined by dissections was not significantly different from the mean total progeny produced by parasitized aphids. Parasitization thus seems to interfere with oogenesis, but not with embryonic development or progeny deposition.