Mermithidae (Nematoda) infection of the aquatic stages of Simulium (Edwardsellum) from the Nine river systems in Kenya

Abstract

Mermithid juveniles recovered from S. damnosum in Kenya were placed in the genus Agamomermis. Varying rates of infection by the mermithids from nine river systems were recorded between 1981 and 1983. In both the Isiukhu and Lusumu rivers, only S. damnosum s.l. larvae were infected. Larvae from the Isiukhu River had an infection rate of 17and from the Lusumu River 13, whereas in the Nzoia and Yala rivers the infection rates were 6 and 4resp. (pooled from S. damnosum s.l. and S. medusaeforme larval infections). S. damnosum s.l. from the Thiba and Nyamindi rivers had very low infection rates of 2for each river system. Aquatic mites were also recovered from the aquatic instars of S. damnosum s.l. from these 2 river systems. Free-living specimenswere not seen in the different river systems. Large mermithid larvae were easily seen inside S. damnosum s.l. or S. medusaeforme. The Parasitized Simulium larva had characteristic distended abdomens and the worms inside showed a bright green colouration.The present data, together with previous findings, indicate that mermithids are a potential biocontrol agent.