Aedes aegypti pharate 1st instar quiescence: A case for anticipatory reproductive plasticity

Abstract

Aedes aegypti mosquitoes use pharate 1st instar quiescence to cope with fluctuations in water availability hosting a fully developed 1st instar larvae within the chorion. The duration of this quiescence has been shown to affect larval fitness. This study s ought to determine if an extended egg quiescence can elicit a plastic response resulting in an adult phenotype distinct from adults reared from short quiescence eggs. Our findings indicate that extended pharate 1st quiescence affects the performance and reproductive fitness of the adult female mosquito as well as the nutritional status of its progeny via maternal effects in an adaptive manner. This study demonstrates that phenotypic plasticity results as a consequence of the duration of pharate 1st instar quiescence and alternative phenotypes may exist for this mosquito with quiescence serving as a cue possibly signaling the environmental conditions that follow a dry period. These findings have implications for A. aegypti’s success as a vector, geographic distribution, vector capacity and control.

Diapause and quiescence: dormancy mechanisms that contribute to the geographical expansion of mosquitoes and their evolutionary success

“…Maternal reserves accumulated in eggs directly influence the period of dormancy in the first-instar larvae contained within the eggs [8, 120]. Thus, quiescent eggs pose an important problem for vector control because these eggs can directly contribute to the maintenance of mosquito populations in treated areas.…”

Embryonic Development and Rates of Metabolic Activity in Early and Late Hatching Eggs of the Major Malaria Vector Anopheles gambiae

“…Hatch timing may influence other traits such as insecticide resistance and fitness. Recently Perez and Noriega [38] showed that extended quiescence (eggs induced to hatch after 10 weeks post oviposition instead of after just less than one week for short quiescence) affected performance and reproductive fitness of adult Aedes aegypti females and the nutritional status of their progeny via maternal effect. Specifically, the females from the eggs that underwent extended quiescence survived 10% longer, laid more eggs and produced 14% more viable offspring when reared on a sub-optimal diet of 3% sucrose solution.…”

How climate change affects the seasonal ecology of insect parasitoids

“…In addition, we can envisage two opposite scenarios. In the first, because metabolic rates increase with temperature (Gillooly et al, 2001) and lead to higher energy consumption before the return of favourable conditions (Williams et al, 2012;Xiao et al, 2016), maintaining relatively high metabolic rates during diapause or extended quiescence under a warmer climate would be costly (Perez & Noriega, 2013). Accordingly, the capacity to delay, avert, or reduce diapause duration may be selected in insect populations (Bale & Hayward, 2010), especially when overwintering conditions allow individuals to remain active and reproduce (Forrest, 2016).…”