Effects of entomopathogenic fungus Metarhizium anisopliae on non-target ants associated with Odontotermes spp. (Isoptera: Termitidae) termite mounds in Kenya

Abstract

AbstractTermites are an important component of savannah ecosystems throughout Africa. Despite their importance in the ecosystem, they can be serious pests of structures, houses, rangelands, tropical forestry, and agriculture. For many decades, chemical insecticides have remained popular for termite management worldwide. However, with the growing environmental concerns over pesticides, biological control using entomopathogenic fungi such asMetarhizium anisopliae(Metschnikoff) Sorokin has become an often-considered alternative.Metarhizium anisopliaeis an ubiquitous, naturally occurring pathogen, which has been reported infecting over 200 insect species; therefore, there is concern that use ofM. anisopliaemay affect non-target organisms. The effects ofM. anisopliaeisolate ICIPE 30 were experimentally tested on the ants which associate withOdontotermesspp. termite mounds. Laboratory bioassays were carried out to assess the effects of direct exposure toM. anisopliaeonCrematogaster mimosaeandCamponotusspp. In addition, ant diversity was monitored over 18 months from termite mounds treated withM. anisopliae in situnear the Mpala Research Centre in Laikipia District of central Kenya. Results obtained revealed no effects of direct exposure toM. anisopliaeisolate ICIPE 30 on the mortality ofC. mimosae(F1= 7.29,P= 0.0072) orCamponotusspp. (F1= 13.01,P= 0.0004) in the laboratory. No significant difference in Shannon indices of ant diversity from treated and untreated mounds (F1= 0.016,P= 0.8989) was found. It is evident thatM. anisopliaehas no negative effects on ants that are associated withOdontotermesspp. termites.