The age-composition of field populations and the survival rates in Culex tritaeniorhynchus Giles

Abstract

The age-composition of natural populations of Culex tritaeniorhynchus was investigated in a rural district of Osaka Prefecture during the period from 1968 to 1973,and it was found that the seasonal fluctuations in the age-composition of Cx. tritaeniorhynchus populations were well correlated to the variation of mosquito abundance. The average parous rate of the populations was slightly higher in August (18.1%) than in July (15.4%). The daily survival rate of the female mosquitoes were thus estimated as 0.525 in July and as 0.555 in August, respectively. There was little difference in the daily survival rates among different years.