Browsing by Author "Abraha, Henok"

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    Study on the Biology and Population Variation of Cotesia Flavipes (Hymenoptera: Braconidae) on Chilo Partellus (Lepidoptera: Crambidae)
    (Addis Ababa University, 2003-06) Abraha, Henok; Seyoum, Emiru (PhD)
    Maize and Sorghum are the major staple food crops in the tropics. Of many insects that attack these crops Chilo partellus (Swinehoe) (Lepidoptera: Crambidae) is the most notorious species. Cotesia flavipes Cameron (Hymenoptera: Braconidae) is a co-evolved parasitoid of C. partellus and has been utilized as a biological control of stemborers including C. partellus in many countries. By measuring some life history parameters, the variability of C. flavipes from two different geographic locations, which were reared on two different geographic populations of C. partellus, was studied. The parameters taken were suitability test, developmental time, realized fecundity and longevity. The suitability test was studied at constant temperature of 28oc, while developmental time, realized fecundity and longevity were studied at constant temperatures of 20oc, 25oc, 28oc and 30oc. All the experiments were studied under 12L: 12D photoperiod and a relative humidity of 50- 60%. Data were analyzed using SPSS computer software, when ANOVA results were significant, means were separated by Tukey’s studentized test (HSD). In the suitability test, the best population interaction was when C. partellus and C. flavipes populations were from the same geographic area. Both populations of C. flavipes have shown variability when the hosts were from different geographic populations. The developmental time of C. flavipes increased as the temperature increased, however, the total progeny produced per female and longevity increased as the temperature decreased. Effect of temperature and populations were seen in most of the life history of C. flavipes, which are bases for successful establishment and efficient parasitism.