Variation in morphological characters of Culex tritaeniorhynchus (Diptera: Culicidae), a Japanese encephalitis vector at Mysore, India.

Studies on Culex tritaeniorhynchus Giles, were undertaken to find deviation if any, on the mean of siphonal index, comb scales, pecten teeth, denticles on apical pecten tooth, anal gills index and length of basal hair tufts on siphon in the fourth instar larvae from ground pools of Mysore city and paddy fields outside Mysore. A total of 344 larvae including 172 samples from Mysore and 172 samples from a 26 km radius outside Mysore were collected. Analysis of variance demonstrated significant differences between the two populations on 7 parameters based on morphological characteristics such as comb scales, length of siphon, width of siphon at the middle, length of anal gills, siphonal index, anal gills index and the length of basal hair tufts. So Cx. tritaeniorhynchus from different breeding places in and around Mysore city in south India can be different varieties. One variety comparatively has shorter siphon index ratio, less comb scales, less anal gills index ratio and longer basal hair tufts on siphon than the other one. Mating behavior of these varieties show that, variety from the city pools was moderate eurygamous and the one from mainly paddy fields, moderate stenogamous.