A new method is proposed that avoids manual counting of mosquito larvae in order to estimatelarval abundance in the field. This method is based on the visual comparison between abundance, in a standardizedsampling tray (called an abacus), with 5 (abacus 5) or 10 (abacus 10) diagrammatically preparedabundance classes. Accuracy under laboratory and field conditions and individual bias have been evaluated andboth abaci provide a reliable estimation of abundance in both conditions. There is no individual bias, whetherpeople are familiar or not with its use. They could also be used for a quick estimation of larval treatmenteffectiveness, for the study of population dynamics and spatial distribution.
