The complex hatching response of Aedes eggs to larval density

Abstract. 1. We investigated the effects of hatching medium, larval density and larval instar on egg hatching in Aedes triseriutus (Say) (Diptera: Cuficidae). 2. In a nutrient broth medium, hatching rates, responded positively to low densities of large larvae, but were suppressed by high densities. 3. The magnitude of suppression was moderated through the use of a yeast hatching medium, which provides a food source for the large larvae. Small instars generally exerted positive effects on hatching, with the exception of first in star larvae in the yeast medium, which inhibited hatching at low and moderate densities. 4. The results demonstrate an ability of eggs to assess indirectly the potential risks of hatching through their responses to changes in dissolved oxygen concentration.