A field experiment to test the effect of containers brushing and scrubbing on Aedes aegypti eggs and non-target accompanying dipterans

RUBIO A.; VEZZANI D.

Congreso; II Congress of the Latin American Society for Vector Ecology; 2022

Aedes aegypti populations survive long periods of drought and winter temperatures in theegg stage, which remain attached to the walls of the containers until favourable conditionsoccur. Cleaning of water storage containers may not eliminate all immatures and cleaningtechniques commonly used may lack the specificity needed to effectively remove Ae. aegyptieggs. More extended ovicidal procedures such as “the untadita” and its modificationsrequires concentrated chemicals (chlorine bleach and/or detergent), which not always areaccepted or available in the entire community. In addition, there is a constant need to searchfor environmentally friendly control methods of Ae. aegypti, including the preservation of theaccompanying fauna in the aquatic habitat. In this work, we compare the efficiency of two non-chemical methods, brushing and scrubbing, to remove Ae. aegypti eggs and thecollateral effects on non-target dipterans that lay eggs on container walls. A field experimentwas carry on during March 2022 on pre-existent and standardized flower vases (conic,plastic, black, 300cc) from Benavídez cemetery, Buenos Aires, Argentina. On three groups of70 vases each, the following treatments were randomly applied: BR) brushing with toiletbrush, SC) scrubbing with an all-purpose microfiber cloth and CT) control withoutintervention. In all the treatments, the water contained in the vase was previously emptied toeliminate pre-existing immatures and, after the application of the treatment, the vase wasfilled with tap water up to the top to promote the hatching of the remaining eggs. In twoconsecutive samplings carried out every 5 days, the content of each vase was checked torecord and extract all Ae. aegypti immatures and non-target dipterans. The proportion ofinfested vases (vases with immatures/vases with water) was compared among treatmentswith Chi2 and Tukey tests. The proportion of infested vases of Ae. aegypti was significantlylower in scrubbing than in brushing and control vases (SC: 3/126, BR: 16/129, CT: 26/128;X2(2)=19,99, p