In Vitro Production of Hyphal Bodies of the Mite Pathogenic Fungus Neozygites floridana

Abstract

The fungus Neozygites floridana is a path- ogen commonly associated with the cassava green mite (CGM), Mononychellus tanajoa, and the two- spotted spider mite (TSM), Tetranychus urticae, in South America. Difficulty in culturing N. floridana in vitro has hampered its development as a bioacaricide. A Colombian isolate from TSM was multiplied in TSM and hyphal bodies from infected specimens were inoculated into 18 mycological and tissue cul- ture media. Grace's insect tissue culture medium plus 0.33% lactalbumin hydrolysate and 0.33% yeastolate (GS) afforded vigorous multiplication of hyphal bod- ies (over 106 /mL). The number of hyphal bodies increased with aeration. Final concentration of hy- phal bodies was not affected by fetal bovine serum (FBS), but growth was somewhat enhanced. Hyphal bodies produced germ tubes when transferred from GS medium to Grace's medium plus 10% FBS and shaken at 200 rpm for 24 h. The germinated hyphal bodies, when placed on water agar, produced pri- mary conidia from which capilliconidia were pro- duced. These capilliconidia were infective to both TSM and CGM.