Larval Emergence from Aedes aegypti (Diptera: Culicidae) Eggs Exposed to Hot Air

Abstract

Aedes aegypti (L.) (Diptera: Culicidae) represents a severe threat to human well-being and health due to the arthropod-borne viruses (arboviruses) it transmits. Its control is implemented mainly through massive applications of insecticides directed to the larval and adult stages. To develop an additional method for combating this vector, eggs (7-15 d old) were exposed in groups of 20 to a stream of hot air at temperatures between 32 ± 2°C and 147 ± 2°C for 5 s. The cumulative percentage of emerged larvae at 24 h and 48 h posttreatment was recorded as a measure of response to the hot air treatment. In the untreated control, which was exposed to room temperature (26 ± 2°C), the cumulative emergence of larvae at 48 h was 99.2 ± 1.7%. The cumulative percentage of larval emergence at 48 h ranged from 97.2% at 87 ± 2°C to 67.7% at 147 ± 2.4°C. The biological efficacy of this proposed hot air treatment was, thus, not acceptable. The natural biological attributes of the Ae. aegypti eggs in withstanding heat and desiccation appear to have protected them against the various levels of temperature tested.