Autor(es): Garza-Hernandez, Javier A.; Reyes-Villanueva, Filiberto; Russell, Tanya L.; Braks, Marieta A. H.; Garcia-Munguia, Alberto M.; Rodriguez-Perez, Mario A.

Resumo: Dengue is the most prevalent arboviral disease transmitted by Aedes aegypti worldwide, whose chemical control is difficult, expensive, and of inconsistent efficacy. Releases of Metarhizium anisopliae-exposed Ae. aegypti males to disseminate conidia among female mosquitoes by mating represents a promising biological control approach against this important vector. A better understanding of fungus virulence and impact on reproductive parameters of Ae. aegypti, is need before testing auto-dissemination strategies.Methodology/PrincipalFindings Mortality, mating competitiveness, sperm production, and the capacity to auto-disseminate the fungus to females up to the 5thcopulation, were compared between Aedes aegypti males exposed to 5.96 x 10(7) conidia per cm(2) of M. anisopliae and uninfected males. Half (50%) of fungus-exposed males (FEMs) died within the first 4 days post-exposure (PE). FEMs required 34% more time to successively copulate with 5 females (165 +/- 3 minutes) than uninfected males (109 +/- 3 minutes). Additionally, fungus infection reduced the sperm production by 87% at 5 days PE. Some beneficial impacts were observed, FEMs were able to successfully compete with uninfected males in cages, inseminating an equivalent number of females (about 25%). Under semi-field conditions, the ability of FEMs to search for and inseminate females was also equivalent to uninfected males (both inseminating about 40% females); but for the remaining females that were not inseminated, evidence of tarsal contact (transfer of fluorescent dust) was significantly greater in FEMs compared to controls. The estimated conidia load of a female exposed on the 5th copulation was 5,200 mL(-1) which was sufficient to cause mortality.Conclusion/SignificanceOur study is the first to demonstrate auto-dissemination of M. anisopliae through transfer of fungus from males to female Ae. aegypti during mating under semi-field conditions. Our results suggest that auto-dissemination studies using releases of FEMs inside households could successfully infect wild Ae. aegypti females, providing another viable biological control tool for this important the dengue vector.

Palavras-Chave: Entomopathogenic fungi; Beauveria - Bassiana; Diptera - Culicidae; Control agents; Dengue; Transmission; Mosquitos; Infection; Field

Imprenta: Plos Neglected Tropical Diseases, v. 9, n. 10, 2015

Identificador do objeto digital: 10.1371/journal.pntd.0004144

Descritores: Aedes aegypti - Dengue ; Aedes aegypti - Epidemiology ; Aedes aegypti - Public health

Data de publicação: 2015