Molecular evidence of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) establishment in Ethiopia

Abstract

Cotesia flavipes (Cameron) is an Asian origin endo-larval parasitoid of cereal stemborers in the genera of Chilo, Sesamia and others. It was introduced into Kenya mainly for the control of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) from India, and North and South Pakistan. After introduction, the parasitoid was released in C. partellus prone areas of Eastern and Southern African countries. The establishment rate varies from country to country and region to region within the country. In Ethiopia, the parasitoid was not released, but for the first time recorded in 1999 as identified morphologically. Morphological traits in many instances lead to wrong taxonomic conclusion. Hence, molecular investigation was carried out to confirm whether the parasitoid recorded in Ethiopia is C. flavipes or not by running Polymerase Chain Reaction (PCR) of DNA fragments of C. flavipes collected from Ethiopia and other African and Asian countries. The PCR analysis using 16S gene (primer) indicated that C. flavipes collected from Ethiopia had similar bands with C. flavipes from other countries confirming the correctness of the morphological traits used to identify the parasitoid. Hence, the parasitoid recorded in 1999 in Ethiopia was Cotesia flavipes which was established without release. To partition the differences that could exist among the different populations of C. flavipes and possibly trace the origin of Ethiopian population, advanced molecular techniques such as restricted fragment polymorphism (RFLP) and sequencing will be recommended although the exercises are expensive.