Larval Control II
Larval Control II
Aedes aegypti is the mosquito vector of multiple arbovirus that cause disease, affecting hundreds of millions of people globally. Females must locate suitable places to lay eggs, which is critical for survivorship of their progeny. 4-ethylphenol is a volatile odor compound (VOC) present in Bermuda Grass and has been reported to attract Culex quinquefasciatus, but hasn’t been evaluated for other mosquito species. In the present study, we evaluated the role of 4-ethylphenol as a potential oviposition cue in A. aegypti. Gravid wild type females were used three days after feeding on fresh defibrinated sheep blood, in two-choice assays under controlled conditions (27°C, 70% humidity, 12:12 light cycle). One female was introduced into a cubical cage where two water sources were offered: 50 mL of water with 4-ethylphenol [10-3M] or [10-7M], and 50 mL of distilled water (control). Each cup contained a small piece of Whatman filter paper as an egg-laying substrate. Following an overnight assay, eggs deposited in each cup were counted using a stereomicroscope, and an Oviposition Assay Index (OAI) was calculated as a metric to determine preference, where OAI= (#eggs odor – # eggs control/ total eggs). Data were analyzed using the Wilcoxon rank test to assess statistical significance. It was produced an OAI of -0.85 ± 0.38 (p=9.28-8, n=21), -0.21 ± 0.49 (p=0.2368, n=11) for [10-3M] or [10-7M], respectively. This indicate that 4-ethylphenol is highly deterrent for A. aegypti oviposition at higher concentration, under these conditions. Future assays will examine additional concentrations of 4-ethylphenol to determine potential concentration effects. Preliminary results suggest 4-ethylphenol may be useful as an oviposition deterrent at higher concentrations. We hypothesize this odor will produce attractive responses at lower concentrations and can be used with other compounds for either push or pull strategies as a component of vector surveillance and/or integrated management programs