ARS | Publication request: Virulence of Hypocreales fungi to pecan aphids (Hemiptera: Aphididae) in the laboratory.

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 8, 2008
Publication Date: October 31, 2008
Citation: Shapiro Ilan, D.I., Cottrell, T.E., Jackson, M.A., Wood, B.W. 2008. Virulence of Hypocreales fungi to pecan aphids (Hemiptera: Aphididae) in the laboratory. Journal of Invertebrate Pathology. 99:312-317.

Interpretive Summary: Pecan aphids are major pests in pecan. The pecan aphid complex consists of three species: the yellow pecan aphid, the blackmargined aphid, and the black pecan aphid. Management of these pests currently relies on use of chemical insecticides. There is need for efficacious environmentally friendly alternatives for control of aphids in commercial orchards. As a preliminary step to this end we determined the virulence (killing-ability) of a naturally occurring fungus called Paecilomyces fumosoroseus to the three pecan aphid species under laboratory conditions. By 72 hours after application, the fungus caused > 90% mortality in the blackmargined aphid and the black pecan, whereas < 70% was observed in the yellow pecan aphid. The identification of this killing ability in the fungus to all three pecan aphid species establishes a potential for commercial usage; thus, warranting additional laboratory and field studies.

Technical Abstract: There is need for efficacious biocontrol agents for aphids in commercial orchards. As a preliminary step to this end we determined the virulence of Paecilomyces fumosoroseus to three pecan aphids Monellia caryella, Melanocallis caryaefoliae, and Monelliopsis pecanis under laboratory conditions. Rates of 1 x 107 or 1 x 108 blastospores were applied via a spray tower to 90 mm Petri dishes containing 10 aphids each. Mortality and mycosis were determined after 24, 48 & 72 h. Treatment effects were observed by 48 h post-application, and by 72 h the higher application rate caused > 90% mortality and mycosis in M. caryella and M. caryaefoliae, whereas < 70% was observed in M. pecanis. The identification of pathogenicity of P. fumosoroseus to all three pecan aphid species establishes a potential for commercial usage; thus, warranting additional laboratory and field studies.