The body size of individual male and female Aedes aegypti, recorded as the cubic value of wing length, was correlated with total protein, lipid, and carbohydrate reserves at eclosion. Protein and carbohydrate had a linear relationship, whereas lipids were positively allometric and sex-specific; per unit size, males had substantially higher lipid levels than females. A wide spectrum of imaginal body size resulted by varying larval rearing conditions (crowding, starvation, and optimal food supply), but regardless of treatment, teneral reserves conformed to regression equations related to body size. Therefore, larval food supply was of primary importance in determining imaginal body size and reserves. The minimal irreducible amounts of female reserve components were 69–86% of the teneral protein, and 16–46% of teneral lipids; carbohydrates were mobilized nearly completely. The extent of reserve mobilization was dependent on the availability of drinking water. With free access to sucrose, maximal reserves were synthesized, dominated by tremendous lipogenesis and leading to a linear correlation of body size with total caloric reserves at the outset of the gonotrophic cycle. Blood consumption by large females was more than twice that of small females, but fecundity increased about 4-fold. The efficiency of blood meal utilization for yolk synthesis was proportional to body size. Large females revealed a threshold level in fecundity, below which maternal reserves were required for completion of oögenesis. The total caloric content per mature oöcyte however, was constant under all experimental conditions, with variations in the relative distribution of its protein and lipid, depending on maternal body size. In large females the gonotrophic cycle was completed in a significantly shorter period than in smaller ones that ingested blood of equal volumes.