Variação temporal e espacial de infecção de Ophiocordyceps unilateralis sensu lato (Ascomycota, Hypocreales) em Camponotus (Hymenoptera, Formicinae) em três áreas da Amazônia

Abstract

Ophiocordyceps are the main entomopathogenic fungi. They are highly virulent and may have an important influence on their hosts communities. In the present study, we collected ants of the genus Camponotus infected by fungi belonging to the complex Ophiocordyceps unilatera-lis sensu lato in three areas of the Brazilian Amazon. In Ducke Reserve, two samples were taken, one in the dry season of 2011 and another in the rainy season of 2012. In Parque Na-cional do Viruá and Estação Ecológica de Maracá, the samples were taken during one dry sea-son of 2012. Within each area, nine 250 m-long transects, at least 1 km distant from each oth-er, were sampled. We found 424 infected Camponotus by Ophiocordyceps in various stages of development. The infection rate in the rainy season was on average three times higher than the dry season, probably reflecting the survival and developmental needs of spores, however, even in the dry season there were infected. The infection rate was similar between the three areas despite differences in climate, vegetation and ant species composition. We found 17 Camponotus species infected, but we believe this number is even higher. Hyperpara-site occurrence rate was low, representing 6% of total infected ants found, suggesting little effect on Ophiocordyceps population in these areas. There was no relationship between the number of infected ants and the soil type (in terms of granulome-try). We found morphological differences among the spores infecting different species of ants, indicating that there are several species of the O. unilateralis not yet described, requiring fur-ther taxonomic studies to better understand this relationship.