Neozygites tanajoae sp. nov., a pathogen of the cassava green mite

Abstract

The fungal pathogen Neozygites tanajoae Delalibera Jr., Humber & Hajek sp. nov. (Zygomycetes: Entomophthorales) is being used in Africa as a biological control agent against the introduced cassava green mite (CGM), Mononychellus tanajoa (Bondar) (Acari: Tetranychidae). This fungus is specific to CGM and has been referred to as N. floridana (Weiser & Muma) Remaud. & Keller, a common pathogen of many tetranychid mites. In the present study N. tanajoae is investigated at the morphological and molecular levels and physiological attributes of N. tanajoae and N. floridana are compared. Morphological observations of N. tanajoae isolates generally correspond to N. floridana and to other mite pathogenic species of Neozygites. However, this fungus readily can be distinguished from N. floridana based on 18S rDNA sequences, host ranges, nutritional requirements for growth in vitro, tolerances to cold (4 C) and abilities to withstand specific cryopreservation techniques. N. tanajoae isolates from Brazil and Africa have identical 18S rDNA sequences but they presented 5.7 and 9.94% pairwise distance from N. floridana isolates. N. tanajoae proved to differ sufficiently from other mite-pathogenic fungi referred to as N. floridana to justify the description of a new species.

• biological control
• Entomophthorales
• Mononychellus tanajoa
• Neozygites floridana
• Tetranychus urticae
• Zygomycetes

This study is a collaborative research with the International Institute of Tropical Agriculture, Benin, and was financed in part by CNPq—Conselho Nacional de Desenvolvimento Científico e Tecnológico of the Ministry for Science and Technology of Brazil.