Temperature induces trade-offs between development and starvation resistance in Aedes aegypti (L.) larvae

Abstract

While heightened temperature increases the development rate of mosquitoes, for Aedes aegypti, larvae that commonly experience food limitation in urban habitats, temperature effects on adult production may also be influenced by changes in the capacity of larvae to survive without food. We carried out experiments at 2°C intervals between 20 and 30°C on the growth, maturation rate and the longevity of optimally fed larvae placed in starvation. Overall, both growth rate and starvation resistance were lower in the first three larval instars (L1-L3) as compared to L4, in which greater than 75% of growth occurred. While increased temperature reduced the duration of each instar, it had a U-shaped impact the effect of initial growth on starvation resistance, which increased from L1 to L2 at 20 and 30°C, remained constant at 22 and 28°C, and decreased at 24 and 26°C. Growth from L2 to L3 significantly increased starvation resistance only from 26-30°C. Increased temperature (above 22°C) consistently reduced starvation resistance in L1. In L2-L4, 2°C increments decreased starvation resistance between 20 and 24°C, but had weaker and instarspecific effects above 24°C. These data show that starvation resistance in Ae. aegypti depends on both instar and temperature, generating a tradeoff between increased development rate and reduced starvation survival of early instar larvae, particularly in the lower and middle temperatures of the dengue endemic 20-30°C range. We suggest that anabolic and catabolic processes in larvae have distinct temperature dependencies, which may ultimately cause temperature to modify density regulation of Ae. aegypti populations.

Food Availability Alters the Effects of Larval Temperature on Aedes aegypti Growth

“…Details of preparation are previously described (Padmanabha et al 2011). To simulate a range of food conditions that Ae.…”

“…For example, we recently showed that heightened development rate at increased temperatures can increase the mortality rate of early-instar Ae. aegypti (Padmanabha et al 2011). Because larval mortality as a result of resource competition is known to play a major role in the regulation of adult Ae.…”

Body Size and Wing Shape Measurements as Quality Indicators of Aedes aegypti Mosquitoes Destined for Field Release

“…This change could have an impact on morphological traits of mosquitoes. 61,62 Wing centroid sizes of females from this sampling period were larger (2.92 versus 2.81 mm) than field females sampled in the warmer months (t = 2.25, df = 151, P = 0.03). There was, however, no evidence of a difference in thorax length (t = 0.98, df = 160, P = 0.33).…”

WHATCH’EM: A Weather-Driven Energy Balance Model for Determining Water Height and Temperature in Container Habitats for Aedes aegypti

“…Previous studies have shown that the temperature optimum for Ae. aegypti larval and pupal development, with short development times and high survival rates, is in the range of 24°–34°C (Bar-Zeev 1958; Rueda et al 1990; Tun-Lin et al 2000; Kamimura et al 2002; Mohammed and Chadee 2011; Padmanabha et al 2011b; Richardson et al 2011; Farjana et al 2012; Eisen et al 2014). We found that model-projected water temperatures from May to September 2011 in a representative container (gray, medium-sized bucket located in half shade) consistently exceeded 24°C in Veracruz City and commonly exceeded 24°C in Rio Blanco but very rarely did so in Puebla City (Figure 11).…”