Effectiveness of autocidal gravid trapping and chemical control in altering abundance and age structure of Aedes albopictus

Background Aedes albopictus is a nuisance pest mosquito of public health importance commonly managed with adulticides and larvicides. We investigated whether adding Gravid Aedes Traps (GATs), Autocidal Gravid Ovitraps (AGOs) or In2Care traps would extend the effectiveness of chemical control methods in Wake County, North Carolina, USA, by combining barrier sprays and larval habitat management (LHM) with each trap type at suburban households. We compared these three treatment groups to untreated controls and to backyards treated only with barrier sprays and LHM. Once a week, for ten weeks, we collected adult mosquitoes at each house using lure-baited surveillance traps and dissected a portion of Ae. albopictus females to determine parity. Results Barrier sprays and LHM alone or combined with any supplemental autocidal ovitrap significantly reduced female Ae. albopictus through Week 3 post-treatment. GATs significantly extended chemical control effectiveness for the duration of the study. Compared to the untreated control, the AGO and GAT treatment groups had significant overall female Ae. albopictus reductions of 74% and 80.4%, respectively, with populations aging significantly slower at houses treated with AGOs. Conclusion This household-level study, though limited in size, observed significant reductions in nuisance Ae. albopictus when combining AGOs and GATs with chemical controls for an eight-week period. Delayed population aging in AGO-treated yards suggests that traps also could mitigate disease transmission risk. Future studies should test these control methods at the neighborhood level to evaluate large-scale effectiveness as well as assess the effect of autocidal ovitraps without chemical intervention. (c) 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.