Evidence of the establishment of Cotesia flavipes (Hymenoptera: Braconidae) in continental Africa

Abstract

Cotesia flavipes Cameron has been released several times in Africa for biological control of gramineous stem borers. Establishment has been reported on the Indian Ocean islands of Mauritius, Reunion and Madagascar, however, several attempts to introduce C. flavipes into continental Africa are reported to have failed. Recently, several cocoon masses of C. flavipes were recovered from south-western Kenya where the parasitoid was never released. Identifications of the parasitoids from south-western Kenya were based on morphological characters, allozyme frequencies, and mating experiments with laboratory populations of C. flavipes. It is hypothesized that C. flavipes became established from individuals escaping from a laboratory colony maintained in south-western Kenya in 1991.

Assessing the long-term welfare effects of the biological control of cereal stemborer pests in East and Southern Africa: Evidence from Kenya, Mozambique and Zambia

“…Evidence of the establishment and spread following the release of biological control agents has been highlighted in several studies and surveys (Assefa et al, 2008;Cugala, 2007;Getu et al, 2003;Mailafiya et al, 2011;Moonga, 2007;Omwega et al, 1995Omwega et al, , 1997Omwega et al, 2006;Sallam et al, 2001). In addition, the parasitism-effect and suppression-effect of the released biological control agents has been demonstrated and confirmed the effectiveness in reducing pest densities (Cugala, 2007;Jiang et al, 2006;Zhou et al, 2001).…”

“…The higher net benefits for Kenya are due to the scattered release sites that allowed the natural enemies to spread and cover more extended agricultural areas. The spread started from the coastal region (Overholt et al, 1994), and at Mbita, in western Kenya where the BC agents inadvertently escaped from the laboratory colony (Omwega et al, 1995), followed by spread from other well-distributed release sites in Central, Eastern and the Rift Valley of Kenya. In Mozambique, the majority of the release points were concentrated in the south, and in Zambia, most releases were done near the border; consequently, the BC agents spread to the neighboring country.…”

Biology and Management of Economically Important Lepidopteran Cereal Stem Borers in Africa

“…Parasitism continued to increase during the next two years with average parasitism of about 13% in 1999 (228). Surveys in other maizegrowing areas of Kenya showed that C. flavipes was present in the Eastern Province (183) and in the area bordering Lake Victoria in western Kenya (139). In the Eastern Province, C. flavipes was found in low densities in 1996 and then released at three sites in 1997.…”

“…Parasitism during the season following the releases was about 14% (183). C. flavipes was never intentionally released in western Kenya, but Omwega et al (139) speculated that the establishment was the result of insects that escaped from a local laboratory colony in 1992. However, parasitism in western Kenya has not increased to the levels observed in coastal Kenya or the Eastern Province (133).…”

The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM

“…Importation of parasitoids has been used in the USA in response to the accidental introduction of O. nubilalis in the early 1900s; the tachinid fly, Lydella thompsoni (Diptera: Tachinidae), and the wasps, Macrocentrus cingulum (Hymenoptera: Braconidae) and Eriborus terebrans (Hymenoptera: Ichneumonidae), have become established but do not consistently maintain O. nubilalis populations below economic levels (Anonymous, 1990;Mason et al, 1994). Similarly, the parasitoid Cotesia flavipes (Hymenoptera: Braconidae) was introduced to Kenya from Pakistan (Omwega et al, 1995) to control the spotted stem borer, Chilo partellus (Lepidoptera: Crambidae). This pest was accidentally introduced into Africa before the 1930s and has become one of the most damaging pests of maize (Tams, 1932;Overholt et al, 1997).…”