Performance of the aphid parasitoid, Diaeretiella rapae (m'intosh) towards certain aphid species in Egypt

Abstract

Survey and population of the aphid species Brevicoryne brassicae L., Aphis cracciuora (Koch), Aphis nerii Boyer de Fonscolombe., Hyalopterus pruni (Geoffroy) and Hypermoyzus lactucae L. and its parasitoids were studied at Kafr Saqr district during1 two successive seasons 2011-2013. Obtained results and showed that Diaeretiella rapae (M'Intosh) was the dominant on aphid species in this study, where it occupied 81.79, 55.25, 51.20, 54.95% and 86.94, 63.77, 52.61, 52.53% on aphid species, B. brassicae, A. cracciuora, A. nerii and H. pruni during the two seasons, respectively. The mean percentages of parasitism were 39.32, 9.14, 16.08, 4.66 and 43.45, 8.68, 13.22, 5.37 on the same aphid species on cabbage, fababean, dafla and reed plants in both seasons, respectively. Total developmental times (Sting-Adult) were 15.58±0.69, 12.17±0.75, 17.52±0.70 and 15.37±0.71 days. Sex ratio were (Female:Male) 1.2:1, 1.07:1, 1.014:1 and 1:1.09 on last aphid species, respectively during the two seasons. A significant positive relationship was found between higher parasitism percentages of D. rapae and higher nutrient composition of both total lipids and free amino acids in tested aphids. © 2014 Academic journals inc.