Aims: Control of diurnal Aedes aegypti with mycoinsecticides should consider the exposure of fungus-treated adults to sunlight, and especially to UV-B radiation that might affect activity of conidia applied on the mosquito's surface. Methods and Results: Germination of Metarhizium anisopliae s.l. IP 46 conidia on SDAY medium was not affected at the lowest level of radiation with UV-B, 0.69 kJ m(-2), but was retarded and reduced at higher 2.075 and 4.15 kJ m(-2), and completely inhibited at >= 8.3 kJ m(-2). In contrast, germination of conidia applied onto fibreglass nettings and exposed from 0 to 16.6 kJ m(-2) did not differ significantly among levels of irradiance exposure and the controls. There was also no significant impact of UV-B up to 16.6 kJ m(-2) on the adulticidal activity of IP 46 and on the subsequent conidiogenesis on cadavers. The Quaite-weighted UV-B irradiance in the laboratory (1152 mW m(-2)) was higher than the natural sunlight irradiance observed in the city of Goiania in Central Brazil on midday (706 mW m(-2) in August to 911 mW m(-2) in October 2015). Conclusions: UV-B does not impair the activity of IP 46 conidia applied previously to radiation on A. aegypti adults. Significance and Impact of the Study: Findings contribute to a better understanding of the effectiveness of M. anisopliae against day-active A. aegypti and its potential for biological mosquito control.