# Repellent and Insecticidal Efficacy of Four Water‐Soluble Formulations of Essential Oils Against Aedes aegypti

## TL;DR

This study tests water-soluble essential oil formulations on mosquito nets to repel and kill Aedes aegypti mosquitoes, finding some oils as effective as DEET.

## Contribution

The study introduces water-soluble essential oil formulations as a potential alternative to DEET for mosquito control.

## Key findings

- Cymbopogon citratus, Eucalyptus globulus, and Origanum vulgare at 250 mg/mL showed 93.3%–100.0% repellent effect and 180 min protection time.
- Cymbopogon citratus at 250 mg/mL had a 26.7% insecticidal effect, comparable to 100 mg/mL DEET.
- Lower concentrations of essential oils (10 and 100 mg/mL) showed minimal insecticidal effects (0%–6%).

## Abstract

Arboviral diseases transmitted by the Aedes aegypti mosquito cause high morbidity and mortality worldwide.

To evaluate the repellent and insecticidal efficacy of water‐soluble formulations of essential oils impregnated into mosquito nets against the adult stage of A. aegypti.

A randomized laboratory bioassay was conducted using a controlled factorial design to evaluate four essential oil formulations (Eucalyptus globulus, Cymbopogon citratus, Origanum vulgare, and Mentha piperita) at concentrations of 10, 100, and 250 mg/mL. Each experimental group consisted of 60 laboratory‐reared adult female A. aegypti specimens. The repellent effect, protection time, and insecticidal effect were evaluated by exposing the insects to a sedated animal bait (Rattus norvegicus albinus) covered with a mosquito net impregnated with the formulations of essential oils and DEET, as a positive control.

The highest efficacy was seen in C. citratus, E. globulus, and O. vulgare at 250 mg/mL, with 93.3%–100.0% repellent effect and 180 min of protection time, similar to that obtained by 100 mg/mL DEET. The highest insecticidal effect was observed in C. citratus (26.7%) at a concentration of 250 mg/mL, similar to that observed in 100 mg/mL DEET. The repellent effect and protection time varied for each concentration tested, except for the insecticide, in which concentrations of 10 and 100 mg/mL had a similar effect (0%–6%).

The repellency of water‐soluble formulations of essential oils of C. citratus, E. globulus, and O. vulgare at 250 mg/mL, compared to 100 mg/mL DEET, represents a possible and complementary alternative for mosquito control.