How much do you need to survive? Minimal nutritional levels to complete the development on Aedes aegypti (Diptera: Culicidae)

Abstract

Aedes aegypti mosquito larvae develop in various aquatic microhabitats, including water-holding tires, cups and bottles. These environments may vary in nutritional characteristics, an important factor for the development of larvae and resulting adult mosquitoes. Compromised larval nutrition can result in developmental failure or affect the growth and reproductive capacity of adults. Understanding these nutritional necessities can help optimize the laboratory rearing of mosquitoes. We tested the effects of sixteen (0, 0.0013, 0.0033, 0.0066, 0.0133, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.1, 0.15, 0.2, 2 g/L) different food concentration treatments of Spirulina Alcon® larval diet on larval survival and life history characteristics of Ae. aegypti. The experiment was conducted under controlled conditions, with a temperature of 27 ± 2ºC, relative humidity of 70–80 % and a photoperiod of 12:12 h. A total of 623 (43.26 %) of the initial 1440 Ae. aegypti individuals died during the experiment. Survival curves differed significantly among food concentration treatments (Chi-Square Test = 1271, df = 15, p < 0.001). The concentrations of 0.025 (60/66.66 %) and 0.03 g/L (67/74.45 %) had the lowest survival rates and 0.15 g/L (76/84.45 %) the highest. The concentrations of 0.025 and 0.03 g/L had the shortest larval development times (8.80; 8.86 days) and longevity (9.95; 8.70 days), but adult sizes were smallest for 0.025 (3.00 mm) and largest for 0.03 (3.15 mm). The concentration of 0.15 g/L had the longest larval development time (9.59 days) and longevity (12.41 days), with intermediate adult size (3.09 mm). Laboratory survival rates for Ae. aegypti are generally associated with high mortality on low-quality and low-quantity of resources. Nutritional stress was found to impair larval development, as well as adult size and longevity. Analyzing responses to different feeding regimes is important for understanding the main mechanisms involved in larval development and the requirements for optimizing mosquito rearing systems.