The survival and molting incidence of fifth-instar nymphs of Panstrongylus megistus (Burmeister, 1835), a vector of Chagas; disease, were investigated following sequential heat shocks in which a mild shock (35 or 40 degreesC, 1 h) preceded a more drastic one (40 degreesC, 12 h). The shocks were separated by 8-, 18- 24-, or 72-h periods at 28 degreesC. The heat-shock tolerance response was more effective when the first shock was given at 40 degreesC. When the period between shocks was 18 h, the tolerance to sequential shocks tin terms of specimen survival) weakened, which suggested a transient control of the process that enables the organism to circumvent the unfavorable effects of severe shock. In tel ms of molting incidence, the heat-shock tolerance was only demonstrated when the period between the first shuck at 40 degreesC for 1 h and the second shock at 40 degreesC for 12 h was greater than or equal to 24 h. These results are the first to demonstrate the induction of heat-shock tolerance in a blood-sucking hemipteran.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.384510513