SPECIES SPECIFICITY IN THE CIRCADIAN PATTERN OF MOSQUITOES

Abstract

The effect of light conditions on the activity of the mosquitoes, Armigeres subalbatus, Aedes japonicus, Aedes togoi, Aedes flavopictus, Culex tritaeniorhynchus, and C. pipiens, was investigated with respect to circadian rhythm. The patterns of activity of these 6 species showed specific differences under 12L (740 lux)-12D (0 lux) and under 12L (742)-12D (2). Armigeres exhibited spontaneous activity under each of the following conditions of continuous light intensity : zero, 2,740,and 7,240 lux. The spontaneous activity pattern varied with the change of light intensity. The activity of Armigeres under continuous illumination and under the conditions of 12L-12D were compared with the results previously obtained on the circadian rhythm in C. pipiens. The comparisons tentatively suggest that there exist specific light intensities for the spontaneous activity of each species and this causes the species to exhibit a specific activity pattern under the conditions of 12L-12D. On the basis of these results, field activity such as the biting cycle of species or the circadian succession of a mosquito community in biting has been interpreted.