Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 1998
Publication Date: N/A
Interpretive Summary: The collection and identification of fungal pathogens of insect pests is a vital means to find new possible alternatives to the use of chemical pesticides. Fungi (but not viruses or bacteria) cause fatal diseases in sucking insects such as aphids and whiteflies, so the complete character- ization of these fungi assists the search for new ecologically benign options for insect control. An unknown, new fungal pathogen of whiteflies in the southern US did not fit well in any known genus; the new fungus was compared to known fungi & described as a new genus and species, ORTHOMYCES ALEYRODIS, that expanded both the range and interpretation of essential taxonomic characters for its closest relatives. No live ORTHOMYCES specimens were available for study, but the means of spore dispersal (an important character) was inferred from the dead specimens, differs markedly from all of its relatives, and could affect the relative potential of this fungus as a biocontrol agent. It is highly likely that pure cultures of ORTHOMYCES can be isolated the next time it is found; such cultures will be vital to assess ORTHOMYCES' effectiveness against economically devasting pests such as silverleaf whitefly and the commone greenhouse whitefly or even other pests such as aphids and thrips.
A new genus and species of fungus, ORTHOMYCES ALEYRODIS Steinkraus, Humber & Oliver gen & sp. nov. (Entomophthorlaes: Entomophthoraceae) is described. In 1994 and 1995 this fungus apparently caused epizootics in high populations of the bandedwinged whitefly (TRIALEURODES ABUTILONEA) in Alabama on cotton and cocklebur. In 1996, T. ABUTILONEA populations were lower and no infected specimens were found. This is the first report of a entomophthoralean infecting an aleyrodid in the New World and the first report of entomophthoralean epizootics in whiteflies.