Survival and development of immature Aedes aegypti in artificial desiccating breeding sites under laboratory conditions

Abstract

The ability of aquatic stages of Aedes aegypti (Diptera: Culicidae), key vector of dengue, chikungunya and Zika viruses, to survive in minimal residues of water has remained unstudied. We found that larvae eclosed from up to 50% of eggs set in permanent water films on water agar (at 1–2% agar), and some (≤9.5%) of these first‐instar larvae developed to second instar (L2). Mean larval survival was about 2 weeks; the longest periods of survival were 31.6 and 38.7 days in a water film and in free water controls, respectively. In another test, L3 moved in the films, with the greatest displacements of the larvae being up to 45 mm per day in the first 3 days; subsequent displacements in the water film were distinctly reduced during the next 20 days by which time all L3 had died. L3 did not detect or move in any directed manner in the film towards nearby small quantities of free water. Most pupae (≥93.7%) placed into water films or in water survived and developed to adults within 3 days. The unexpected survival of aquatic immature stages in desiccating breeding sites might be a reason for both the tenacious persistence of mosquito populations in seasons with infrequent rainfall and failures of classical control strategies against this important vector.

Les propriétés biotiques et abiotiques des gîtes larvaires d’Aedes aegypti et leur influence sur les traits de vie des adultes (synthèse bibliographique)

“…Les larves d'Ae. aegypti sont également retrouvées dans des gîtes moins conventionnels comme les fosses septiques (Burke et al, 2010) et peuvent survivre dans des gîtes ayant des volumes d'eau très réduits (Luz et al, 2017). Ces caractéristiques témoignent de la grande adaptabilité du vecteur aux variations environnementales et favorise sa persistance pendant les saisons sèches (Kahamba et al, 2020).…”