Application of copper-based ovitraps in local houses in West Sumatra, Indonesia: a field test of a simple and affordable larvicide for mosquito control

BACKGROUND: The application of oviposition traps (ovitraps) is one of the currently available rational methods used in mosquito control campaigns because it eliminates the larval stage. However, the use of current larvicides is hampered by their cost and applicability. Therefore, a more economical and practical alternative is urgently needed. We previously reported that copper in liquid form is a promising candidate due to its potent larvicide properties in a laboratory setting, affordability, and availability. METHODS: In the present study, a field test was performed by randomly placing copper-filled plastic pots with a concentration of 10 ppm in 21 local houses in Painan City, West Sumatra, Indonesia. Three of these pots including a control were placed inside, while another two were placed outside each of the houses. RESULTS: After 14 days, a large number of dead first and second instar larvae of Aedes spp. were observed in the copper-filled pots. Larvae in the control pots were all viable and thriving. Unhatched eggs and pupae were detected in several pots in the copper-treated group but were excluded from the analysis. CONCLUSIONS: Our field data confirmed that copper is a potential larvicide for ovitraps, particularly in under-resourced areas.