Effect of acute and chronic exposure to ammonia on different larval instars of Anopheles darlingi (Diptera: Culicidae)

ABSTRACTAnopheles darlingi (Diptera: Culicidae) is the most important vector of malaria in South America and has already been found in peri ‐urban areas that commonly contain toxic nitrogenous compounds, such as ammonia. The adaptation of mosquitoes to polluted breeding sites can increase their distribution and affect the dynamics of vector‐borne diseases such as malaria. Therefore, the present study investigated the tolerance of la rval instars ofAn. darlingi to ammonia under acute and chronic exposure conditions.Anopheles darlingi larval mortality, development time, and pupal and adult production using larvae of the 1st (L1) and 3rd (L3) instar were assessed as both acute and chronic effects of exposure to different concentrations of ammonia. Lethal concentrations (LCs) for L1 larvae were lower than LCs for L3 larvae. In general, higher ammonia concentrations caused an increase in larval mortality, especially in chronically exposed L1 larvae. The larval development time in L1 and L3 was longer with chronic treatment and decreased with increasing concentrations of ammonia. The number of pupae was very low for acutely exposed L1 and L3 larvae. Likewise, the probability of adult production decreased with increasing ammonia concentrations. This is the first report on the tolerance ofAn. darlingi to pollutants.

Source: Journal of Vector Ecology - May 22, 2019 Category: Biology Authors: Alyne C. A. Dias, Moreno M. S. Rodrigues, Alexandre A. Silva Tags: Original Article Source Type: research