Nutrient accumulation in three mosquitoes during larval development and its effect on young adults.

Information on the accumulation of nutriquitoes per cup (400 ml) in duplicate. The adults tional reserves during larval development of had access to water only and were predomimosquitoes is practically non-existent. Wigglesnantly at rest. These experiments were carried worth (1942) had shown with elegant histo ) t logiout a year later and repeated 6 times. The assays cal evidence that fourth instar larvae of Aedes for nrotein. lioids. slvcosen. trehalose and other r t p , p , g y g , oegypti (Linn.) synthesize protein, fat and glysugars have been recently described (Van Hancogen, but no quantitative measurements are del 1985a, 1985b, 1986). The average result of available for any instar. In this note, I will each test was treated as a single data point and present the accumulation of larval protein, lipthe averages of the experiments were used in the ids, glycogen and trehalose of 3 mosquitoes calculation of standard errors. maintained under identical conditions of diet, Aedes aegypti reached the fourth instar after Iight and temperature. The results are a measure 4 days, as judged by size, and pupated on the for larval growth (protein) and nutritional resixth day. Culex nigripalpus and Cx. quin4uefasserves (lipids and carbohydrates) that influences ciofus reached the fourth instar after 5 days and the survival and flight range ofthe newly eclosed pupated on the seventh day. adult before it finds a sugar or blood meal. The Protein. As expected by the difference in advantage of using protein as a criterium for growthrate,Aedeslawaeaccumulatedmoreprolarval growth instead of weight has been applied tein during the first 3 days than the two Cul.ex and discussed in a previous article (Van Handel species, but between days 3 and 5 the rates of 1986). In the present work, where larvae, pupae protein accumulation were similar in the 3 speand adults are compared, the advantage of using cies. The maximum rate was between day 3 and protein instead ofweight is even clearer. 4 fot Aed.es (140 pe/day) and between day 4 and Aedes aegypti, Culex nigripalpusTheobald and 5 for Culex, (185 &g/day). However, the 3 species Culex quinquefasciatus Say, all from established reached maximal protein content (approxicolonies, were raised under 12 hr light12 hr mately 400 p.g each) at the same time (on the dark at 26"C in 22 x 32 cm enamel pans con5th day) with little or no further addition (Fig. taining 500 ml water and 150-160 larvae. Each 1). These results are in agreement with earlier treatment consisted of 2 pans. On the day of experimentsinwhichtheeffectof differentdiets hatching, and 3, 4, 5 and 6 days later 100 mg was investigated (Van Handel 1986). food (3 parts dried brewer's yeast and 1 part porcine liver powder, purchased from ICN Biochemicals) was added. Larvae were collected at 0900 hr and food added thereafter. Larvae were analyzed in duplicate in pools of 25 on day 3, older larvae and adults in pools of 10. All chemical assays were repeated until the difference among replicates was less than 5 percent. Early pupae are predominantly male and late pupae predominantly female. Pupae were therefore analyzed when most Iarvae had pupated, but before adult emergence had begun, to minimize sex bias. The larval experiment was repeated 10 times over a 6 month period. Adults for chemical analysis and starvation were collected within a few hours after eclosion. Starvation was determined at 26'C with 50 mos-