Sl. Garcia et al., Survival and molting incidence after heat and cold shocks in Panstrongylusmegistus Burmeister, MEM I OSW C, 94(1), 1999, pp. 131-137
Survival and molting incidence were studied after heat (40 degrees C) and c
old (0 degrees C) shocks in specimens of Panstrongylus megistus with the ai
m of establishing its response to temperature stress tinder laboratory rear
ing conditions and to understand occasional changes in the biological chara
cteristics of specimens captured in nature. The response to the thermal sho
cks was found to vary as a function of the temperature and duration of the
shock, developmental phase and sex of the specimens, and in certain cases,
the insect habit and nourishment conditions. P. megistus specimens were fou
nd to be less resistant to the heat shock assay than Triatoma infestans, an
other reduviid species. The short cold shock affected survival of P. megist
us more than did the heat shock, survival of fully-nourished specimens bein
g preferential. The response of adults to the short cold shock was affected
by sex, males being generally less resistant. The insect sylvatic habit wa
s found to seldom affect the thermal shock response established for specime
ns with domestic habit. A decrease in molting frequency and sometimes a slo
wdown of the molting rate were found after the short heat and cold shocks,
possibly promoted by change in hormonal balance, and differing from pattern
s reported for T. infestans. The results indicate that no generalization sh
ould be made for different reduviid species in terms of the effects of temp
erature shocks.