EUROPEAN JOURNAL OF ENTOMOLOGY

Eur. J. Entomol. 103 (4): 799-804, 2006 | DOI: 10.14411/eje.2006.109

Prevalence and association of the laboulbenialean fungus Hesperomyces virescens (Laboulbeniales: Laboulbeniaceae) on coccinellid hosts (Coleoptera: Coccinellidae) in Kentucky, USA

James D. HARWOOD¹, Carlo RICCI², Roberto ROMANI², Kevin M. PITZ¹, Alex WEIR³, John J. OBRYCKI¹

¹ Department of Entomology, University of Kentucky, S-225 Agricultural Science Center North, Lexington, KY 40546-0091, USA; e-mail: James.Harwood@uky.edu

² Department of Agricultural and Environmental Sciences, Perugia University, Borgo XX Giugno 74, 06121 Perugia, Italy

³ Faculty of Environmental and Forest Biology, 241 Illick Hall, 1 Forestry Drive, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA

The laboulbenialean fungi occur throughout the world and are closely associated with a range of arthropods, including many coleopteran hosts. Throughout the summer of 2004, coccinellids were collected from a Bluegrass savanna woodland ecosystem, dominated by blue ash Fraxinus quadrangulata and Chinkapin Oak Quercus muehlenbergii, and the adults were examined for the presence of Hesperomyces virescens using binocular and scanning electron microscopy. Over 80% of adult Harmonia axyridis, a species previously reported as having a persistent association with the fungus, were infected. No significant differences were observed in incidence on male and female hosts, however, the distribution of fungus differed between sexes. Female H. axyridis had a greater percentage of infection on their elytron compared to other parts of their body whilst male infection was concentrated around their elytra, legs and abdomen. Although infection rates were significantly lower, we report, for the first time, the presence of this fungus on the hosts Cycloneda munda, Brachiacantha quadripunctata and Psyllobora vigintimaculata. This is the first study documenting the incidence of this insect-associated fungus with these native coccinellids of North America. In the samples collected from the Bluegrass savanna, two species (Coleomegilla maculata and Hyperaspis signata) were not infected by this fungus.

Keywords: Insect-associated fungi, Coccinellidae, Laboulbeniales, ectoparasitic fungi

Received: January 13, 2006; Revised: April 25, 2006; Accepted: April 25, 2006; Published: October 2, 2006  Show citation