Published online by Cambridge University Press: 10 July 2009
In view of the great diversity of opinion on the subject of sex ratio and order of emergence of the two sexes of adults in laboratory-bred mosquitos and those occurring in nature, 70 experiments spread over a period of 1 year, were conducted in the laboratory at room temperature to study (a) the order of emergence of the sexes, (b) proportions of sexes in the total output in a brood, (c) the effect of larval and pupal mortality, (d) the effect of food, and (e) of temperature on sex ratio. The common species, C. fatigans, was chosen for the purpose.
By a statistical evaluation and graphical representation of the data it has been shown that males hatch out significantly earlier than females, and that the larval life of the males is significantly shorter than that of the females.
It is concluded that the sexes emerge in a 1: 1 ratio, although a small number of aberrant cases with a significant preponderance of one sex or the other may occur.
Larval as well as pupal mortality below 20 per cent. does not seem to affect the sex ratio; nor has it been possible to establish any relationship between sex ratio and mortality in any of the aquatic stages.