The Systematics of the Genus Strongwellsea (Zygomycetes: Entomophthorales)

SUMMARY

The validity of the generic name Strongwellsea is upheld for fungi that create a large hole in the abdominal pleuron of a limited range of adult muscoid flies. The most important generic characteristics are discussed with an emphasis on those which have been incompletely known or inaccurately evaluated. The generic and specific characteristics of S. castrans are separated, and both taxa are emended to incorporate significant characteristics that were not included in the original combined generic and specific description. Fungal development is not restricted to the abdominal hemocoele since hyphae may occur in the thoracic hemocoele and throughout the nervous system. In some circumstances, the infection develops more frequently in the female flies. Spiny orange resting spores and the formation of secondary spores are reported. A second species, S. magna, is described from a fly in the Muscidae; S. castrans is restricted to hylemyoid flies in the Anthomyiidae. Comparisons of taxonomically significant spore measurements indicate that preparatory methods significantly affect the apparent size and shape of primary spores; suggestions for taxonomic methodology are included.