Accelerating the Morphogenetic Cycle of the Viral Vector Aedes aegypti Larvae for Faster Larvicidal Bioassays

Abstract

Any bioassay to test new chemically synthesized larvicides or phytolarvicides against Culicidae and more harmful mosquito species, such as Aedes aegypti and Aedes albopictus, which specifically transmit dengue, yellow fever, chikungunya viral fevers as well as Zika virus, or Anopheles gambiae, a vector for malaria and philariasis, requires thousands of well-developed larvae, preferably at the fourth instar stage. The natural morphogenetic cycle of Aedes spp., in the field or in the laboratory, may extend to 19 days at room temperature (e.g., 25°C) from the first permanent contact between viable eggs and water and the last stage of larval growth or metamorphosis into flying adults. Thus, accelerated sequential molting is desirable for swifter bioassays of larvicides. We achieved this goal in Aedes aegypti with very limited strategic and low-cost additions to food, such as coconut water, milk or its casein, yeast extract, and to a lesser extent, glycerol. The naturally rich coconut water was excellent for quickly attaining the population of instar IV larvae, the most advanced one before pupation, saving about a week, for subsequent larvicidal bioassays. Diluted milk, as another food source, allowed an even faster final ecdysis and adults are useful for mosquito taxonomical purpose.

First national-scale evaluation of temephos resistance in Aedes aegypti in Peru

“…Author details 1 Laboratorio de Referencia Nacional de Entomologia, Centro Nacional de Salud Pública, Instituto Nacional de Salud, Lima, Peru. 2 Laboratório de Fisiologia e Controle de Artrópodes Vetores-LAFICAVE, Instituto Oswaldo Cruz (IOC)-Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. 3 Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA.…”

“…Aedes aegypti is the main vector of arthropod-borne viral infections transmitted to humans, which include dengue, yellow fever, chikungunya and Zika [ 1 , 2 ]. The vector is present in tropical and subtropical regions of Southeast Asia, the Pacific and the Americas, where these viruses also circulate.…”

Atividade larvicida de extratos vegetais de espécies do cerrado sobre Aedes aegypti L. (Diptera: Culicidae)

“…A fase larvária dura, em média, cinco dias quando as condições são favoráveis. No entanto, baixa temperatura e escassez de alimento podem estender o 4º estágio larvário por várias semanas, antes de sua transformação em pupa (FONTANA et al, 2020). A fase larvária é a que apresenta maior vulnerabilidade, dado ao confinamento espacial.…”