%0 Journal Article
%T Influence of mating frequency and parasitoid age on reproductive success of Trichogrammatoidea sp. nr. lutea Girault collected from Plutella xylostella Linnaus in Kenya
%A Zipporah O.et al.
%J International Journal of AgriScience
%D 2013
%I International Academic Journals
%X This study was carried out to investigate the reproductive fitness parameters, that is, parasitism, adult progeny production, and sex ratio of a native egg parasitoid Trichogrammatoidea sp. nr. lutea Girault (Hymenoptera: Trichogrammatidae) collected from Plutella xylostella Linnaus (Lepidoptera: Yponomeutidae) in coastal Kenya, reared on Corcyra cephalonica Sainton (Lepidoptera: Pyralidae) in the laboratory. Freshly emerged mated female adults (0-24hr old) with no previous oviposition experience, were placed individually in separate glass vials. Ten replicates (each replicate composed of a single female) were made; each female was offered 40 eggs in an egg card daily. Egg cards were placed in separate vials at constant temperature and humidity to await emergence. The daily and lifetime number of parasitized (blackened) eggs, adults which emerged from the parasitized eggs were counted and recorded, together with the number of females out of the total progeny (number of adults). Percentages for all the tested parameters were also calculated. In another set of experiment, the possibility that the presence of males may bring material benefits to the parasitoid females in terms of enhancing sex ratio and other reproductive fitness parameters was investigated by placing male together with female in same vial throughout its lifetime. Highest progeny production, parasitism and sex ratio (percentage of females) was obtained during the first day of host exposure, decreasing with parasitoid age. No significant difference (P>0.05) was found in the overall lifetime offspring progeny, parasitism and sex ratio of single mated females and one placed together with male throughout its lifetime. Females of T. sp. nr. lutea received enough sperm from one mating to allocate optimum sex ratio. In order to achieve highest reproductive success of Trichogramma parasitoids during mass production for biological control of Lepidopteran pests, it is important to use younger wasps than old ones. Besides, there is no possibility that the presence of males may bring material benefits to the parasitoid females in terms of enhancing sex ratio and other reproductive fitness parameters.
%U Biological control, mass production, parasitoid age, reproductive success, Trichogramma