Effects of variation in quality of leaf detritus on growth of the eastern tree-hole mosquito, Aedes triseriatus (Diptera: Culicidae)

Growth of larvae of the eastern tree-hole mosquito, Aedes triseriatus (Say), measured as survival to adulthood, development time, and body mass at adult emergence, was significantly better when larvae were provided with fresh rather than senescent beech leaves as food substrate. Leaf type affected larval growth performance independently of ration of leaf available per larva when the ration level was high and larvae were not densely crowded, but leaf type and ration level had interactive effects on larval growth performance when ration was more limiting and larvae denser. Fresh leaves contained about twice as much nitrogen, had a lower carbon:nitrogen ratio, leached more mass into water, and contained significantly more soluble protein and carbohydrate than did senescent leaves. Thus, the observed growth responses could be explained on the basis of variation in nutrient content of, and greater leaching from, the fresh leaves. Larval growth was also significantly better on intact senescent beech leaves than on leaves that had been leached to remove soluble protein and carbohydrate; it was also significantly better on leaves whose surfaces had flourishing bacterial growth than on leaves with disinfected surfaces. Growth of female larvae fit well a pupation window model where larvae attained a minimum mass to emergence past a minimum development time across a range of leaf substrates varying in quality and quantity.