Comparative Evaluation of the Regular Ovitrap vs an Innovated Larvitrap for Aedes Entomological Surveillance in Tapachula

Abstract

Objective: The objective is to compare a regular ovitrap versus an innovated larvitrap for monitoring Aedes spp. populations. Materials and Methods: A total of 20 regular ovitraps and 20 innovated larvitraps were placed in pairs in 20 houses from the 5 de Febrero neighborhood in Tapachula, Chiapas, Mexico. The innovation consisted in the incorporation of a valve in the lower part of a half tire to drain the contents in a 2 L collection container. The evaluation was carried out during five weeks, collecting eggs and larvae from the ovitraps and innovated larvitraps, respectively. Positivity indexes and insectary production of adult Aedes spp. mosquitoes were compared by collection type. Results: Average positivity index for the five weeks period were 60% for ovitraps and 91.25% for innovated larvitraps. During the five weeks, 4043 Ae. aegypti and 703 Ae. albopictus adult mosquitoes were produced in the insectary from the eggs collected from ovitraps, while from innovated larvitraps were 9014 Ae. aegypti, 1205 Ae. albopictus, and 15 Culex spp. Conclusion: Collection by the innovated larvitrap was more efficient, collecting 3.56 times more Ae. aegypti than with ovitraps, using approximately the same effort in time for replacing the filter paper from traditional 1 L ovitraps. Since the logistics for the storage and placement of larvitraps may still be a disadvantage in comparison with ovitraps, their use could be specifically intended in sentinel sites for mosquito population monitoring for entomological surveillance purposes.