The epizootic potential ofBeauveria bassianafor control of the triatomine vectors of Chagas' disease was investigated by studying the effects of both biotic and abiotic factors on the recycling of a highly virulent fungal isolate from fungus-killed cadavers ofRhodnius prolixus.The conidial production ofB. bassianafrom mummified cadavers ofR. prolixusrequired high RH levels of at least 96.5% RH. At 97% RH and 25°C, the amount of conidia per insect ranged from 5.3 × 106(on first-instar larval cadavers) to 1.7 × 108(on adult cadavers) depending on the size of the different stages of development of the host. Under optimal conditions,B. bassianasporulation fromR. prolixuscadavers took place in 4 to 5 days after death. At a high humidity level (97% RH) the intensity of the conidial production fromRhodniuscadavers was little affected by temperature over a range from 15 to 25°C, but it declined at 28–30°C and was null at 35°C. There was only a weak influence of the blood meal of nymphs and its timing on the conidial production fromB. bassiana-killed cadavers. The recycling capacity of differentB. bassianaisolates, selected for their pathogenic activity toR. prolixus,did not differ. From a vector control standpoint, high humidity appears to be the most crucial climatic constraint. The recycling ability ofB. bassianaon fungus-killedR. prolixusmight contribute to the regulation of triatomine vectors only after applications during the rainy seasons.