Morphological differentiation of eggs and comparative efficacy of oviposition and gravid traps for Aedes vectors at different habitats

Mosquito surveillance is an integral part of understanding mosquito-borne disease, including and not limited to the La Crosse virus. The primary container-inhabiting Aedeni vectors include Aedes triseritatus, Aedes albopictus, and Aedes japonicus. To better understand the efficacy of gravid traps and oviposition traps as surveillance methods for these mosquitoes, field studies were conducted in three different habitat types.

Ae. triseriatus, Ae. albopictus, Ae. japonicus, and Aedes aegypti eggs were described with the aid of color images and SEM. All eggs were broadly cigar shaped with Ae. triseriatus and Ae. japonicus eggs being dull or matte black while Ae. albopictus and Ae. aegypti eggs were shiny jet black. Ae. triseriatus eggs were larger, lighter in color, and have a rougher appearance when compared to Ae. japonicus. Ae. albopictus and Ae. aegypti can be differentiated by the distinct presence of a micropylar collars in Ae. aegypti.

Ovitrap and gravid trap efficacy for the surveillance of Ae. triseriatus, Ae. albopictus, and Ae. japonicus were measured in three different habitats on two different sites. Both sites contained the same 2ha habitats with varying degrees of forest canopy disturbance. Ae. triseriatus was the most abundant mosquito on all sites. Ovitraps and gravid traps were efficient in collecting Ae. triseriatus, while ovitraps were not efficient in collecting Ae. japonicus and Ae. albopictus.