2018-08-202018-08-201998-12LUZ, Christian; TIGANO, Myrian S.; SILVA, Ionizete G.; CORDEIRO, Celia M. T.; ALJANABI, Salah. M. Selection of Beauveria bassiana and Metarhizium anisopliae to control Triatoma infestans. Memórias do Instituto Oswaldo Cruz, Rio de Janeiro, v. 93, n. 6, p. 839-846, Nov./Dec. 1998.0074-0276e- 1678-8060http://repositorio.bc.ufg.br/handle/ri/15663Twenty three isolates of Beauveria bassiana and 13 isolates of Metarhizium anisopliae were tested on third instar nymphs of Triatoma infestans, a serious vector of Chagas disease. Pathogenicity tests at saturated humidity showed that this insect is very susceptible to fungal infection. At lower relative hu- midity (50%), conditions expected in the vector microhabitat, virulence was significantly different among isolates. Cumulative mortality 15 days after treatment varied from 17.5 to 97.5%, and estimates of 50% survival time varied from 6 to 11 days. Maintaining lower relative humidity, four B. bassiana and two M. anisopliae isolates were selected for analysis of virulence at different conidial concentrations and tem- peratures. Lethal concentrations sufficient to kill 50% of insects (LC 50 ) varied from 7.1x10 5 to 4.3x10 6 conidia/ml, for a B. bassiana isolate (CG 14) and a M. anisopliae isolate (CG 491) respectively. Most isolates, particularly B. bassiana isolates CG 24 and CG 306, proved to be more virulent at 25 and 30°C, compared to 15 and 20°C. The differential virulence at 50% humidity observed among some B. bassiana isolates was not correlated to phenetic groups in cluster analysis of RAPD markers. In fact, the B. bassiana isolates analyzed presented a high homogeneity (> 73% similarity).engAcesso AbertoVector controlChagas diseaseEntomogenous fungiVirulenceRandom amplification of polymorfic DNAArtigo10.1590/S0074-02761998000600026