The effectiveness of several types of Malaise traps for the collection of Tabanidae and Culicidae

Comparative tests of a Manitoba trap [cf. RAE/B 54, p. 69] and 7 types of Malaise trap [cf. 54, p. 191, etc.] were carried out in a forest near Stoneville, Mississippi, in May 1970. Earlier results with some of the types of Malaise trap tested have been reported previously [cf. 59, 1836; 60, 1652, etc.]. Tabanus subsimilis Bellardi, T. lineola F., Hybomitra lasiophthalma (Macq.) and Chrysops falvidus Wied. were the 4 most numerous of the 12 species of Tabanids caught. Aedes canadensis (Theo.), A. Vexans (Mg.), A. sticticus (Mg.) and Psorophora ferox (Humb.) were the 4 most numerous of the 20 species of Culicids caught, which included 9 of Aedes, 2 of Anopheles, 4 of Culex and 5 of Psorophora. The greatest number of Tabanids was caught in a Stoneville Malaise trap of natural-coloured saran gauze [cf. 59, 1836] with a black circular plastic decoy 9 in. in diameter. The greatest number of Culicids was caught in an ordinary Malaise trap of either natural-coloured or green saran gauze. Amongst the factors affecting number caught were the colour contrast between a trap and its background, the size of the trap and the size and shape of the entrance.