Temperature preference in Rhodnius prolixus, effects and possible consequences

SCHILMAN, P.E. & LAZZARI, C.R.

ACTA TROPICA

Elsevier Science

Lugar: Amsterdam, Netherlands; Año: 2004 vol. 90 p. 115 - 122

0001-706X

The present work examines the thermal preference of adult R. prolixus along a temperature gradient. The mean preferred temperature differed slightly between sexes: 25.0°C for males versus 25.4°C for females. This preference was not constant, but varied daily by about 0.2°C for both sexes, and reached its highest value at the onset of the dark phase and was lowest during the light phase. A change in the preferred temperature with the level of starvation was also observed (about 1°C lower after 20 days of starvation). Changes in environmental temperature strongly affected the rate of weight loss for both sexes. When insects were maintained for 20 days in a chamber at 32 °C, they lost significantly more weight than when kept at 24 °C; both water loss and nutrient conversion processes are involved. This increase in weight loss rate with increasing temperature would cause a higher biting rate and consequently higher probability of Chagas' disease transmission. Females oviposit across a range of temperatures from 22° to 33°C with a peak at 25°-26°C. These results are compared with patterns of thermopreference in other species of triatomine, as related to differences in their distribution and tolerance to starvation.