Life-History Traits of Two Medically Important Insects Culex quinquefasciatus Say and Musca domestica L. Influenced by Temperature and Humidity

Abstract

Such vital life-history traits as incubation periods, immature durations and total egg-to-adult developmental periods of two medically important dipteran vector species viz., Culex quinquefasciatus Say (Diptera: Culicidae) and Musca domestica L. (Diptera: Muscidae) were exposed to environmental chambers at 25°-32 °C and 60-95% RH to evaluate the impacts of the abiotic factors on growth and development of the insects. Results showed that highly significant decreases in the incubation, larval, pupal and total developmental periods were induced in both the species of insects (P<0,001) by the increase in temperature by 8° C. In accordance with the temperature rise, however as expected, RH had a synchronous effect on all the life-history traits of the experimental insects. It was remarkable to note that C. quinquefasciatus and M. domestica responded differently to the changes in temperature and RH. Further analyses of the experimental data revealed that highly significant but negative correlations (r values between -0.68 and -0.98; P<0.001 each at 18 df) existed between the developmental parameters and the abiotic factors under study. The relevance of the present findings to the SIT (sterile insect technique)-based control programme as well as the effects of climate change on the vector competence in the field have been discussed.

Keywords: Culex quinquefasciatus, Musca domestica, life-history traits, incubation, larval and pupal periods, egg-to-adult development, temperature, relative humidity, climate change.

JEL Classification: Q