Effects of density and larval competition on selected life history traits of Culex pipiens quinquefasciatus (Diptera : Culicidae)

The effects of larval densities of one to four individuals in standard Dros ophila-vials (diameter 25 by 95 mm) on the age at pupation, starved dry wei ght, and wing length of Culex pipiens quinquefasciatus Say were studied. Th is approach required relatively few larvae per replicate and included a con trol treatment, where individual larvae developed in the absence of competi tion. This design also tested for competitive interactions between male and female larvae. Mosquitoes pupated later, and emerged with lighter starved dry adult weight and shorter wings as larval density increased. The size of adult female mosquitoes, particularly their starved dry weight, was sensit ive to larval density and also was influenced by the presence or absence of competition with another female larva. In contrast, the life history trait s Of males did not vary as a function of competition with female larva Fema le larvae were also more likely to die in the highest density treatment. Th is design confirmed previous results and offered a potentially useful exper imental approach to investigate the effects of density-dependent competitio n among mosquito larvae.