An Investigation of the House-Frequenting Habits of Mosquitoes of the British Guiana Coastland in Relation to the Use of DDT

Abstract

Summary Species sanitation has been the dominant directive in mosquito control for 40 years, with attack concentrated on the aquatic stages of these insects by means of widely varying techniques specifically adapted to the breeding habits of each individual species. With the introduction of house spraying with DDT, the adult mosquito becomes the main target, and its domesticity, in biting and resting habits, emerges as the factor determining the success of this new procedure. The human habitation is the “bottle neck” in the life history of a large variety of obnoxious arthropods (not mosquitoes only) where DDT can be applied with the greatest ease and with the maximal effect. Within the house, species sanitation has no significance. Taking into consideration these new concepts in mosquito control, the domestic proclivities of the mosquitoes of the British Guiana coastland have been investigated. For this purpose, material has been collected in six representative localities with varying hydrological characteristics. Observations were taken both by day and by night, and for comparative purposes adult captures were also made with a cattle-baited Shannon dawn trap, and parallel larval surveys have been carried out in most localities. The highly domestic biting and resting habits of A. darlingi have been confirmed, so that the prospects of control of this species, the sole malaria carrier of the region, by spraying with DDT, appear excellent. The same can be said for Aedes aegypti, at present under control in the more densely populated centers by the classical anti-aedes technique. Culex fatigans, with its eclectic biting habits, constitutes a more difficult problem, since spraying of houses will have little effect on its total incidence. Supplementary antilarval measures will be required for its effective control and the prevention of filariasis. Anopheles albitarsis, A. aquasalis an A. triannulatus are all common, but they are zoophilous in their feeding habits and do not enter houses. Aedes taeniorhynchus, Mansonia titillans and Aedeomyia squamipennis enter houses only occasionally, and it cannot be expected that any of these will be influenced by the spraying of houses with DDT.