Reduced hatchability of Anopheles gambiae s.s eggs in presence of third instar larvae

BACKGROUND: We investigated the hatchability rates of freshly laid Anopheles gambiae s.s. eggs in presence of third instars larvae. These experiments were conducted using 30 eggs in larval densities of 20, 60 and 100 larvae in microcosms. These experiments were designed to evaluate the eggs hatchability in habitats with late larvae instars of the same species (experimental) or no larvae at all (control). Freshly laid eggs of An.gambiae s.s. were washed in microcosms containing larvae of third instars in different three densities (20, 60 and 100) and likewise in control microcosms (without larvae). Eggs hatchability was monitored twice daily until no more first instar larvae emerged. The numbers of first instars larvae were recorded daily and lost eggs were considered preyed upon by third instars. FINDINGS: The findings of this study showed that egg hatchability was significantly influenced by larval density. CONCLUSION: The findings of this study suggest that presence of larvae in habitats may significantly reduce hatchability of eggs.