The Gressitt trap for collecting Tabanidae (Diptera).

The names used for modifications of traps described by R. Malaise are discussed, with special reference to those that were described by H. Townes in 1962 and by J.L. Gressitt & M.K. Gressitt in 1962, and it is suggested that the name of the most similar design should be used in preference to the common and confusing use of the term Malaise trap, which is often applied to any of these modifications. Modifications to the Gressitt trap to utilise commercially available containers to retain the catches, to eliminate unnecessary muslin reinforcement and suspensory line, and to test durable and light fine-mesh polyester marquisette as the netting material, are described. The results are given of tests with the trap, in comparison with a Manitoba trap, for collecting Tabanidae in Texas in 1975. The modified Gressitt trap took 17 370 flies, as compared with 4684 in the Manitoba trap, including 10 more species (one a new state record) and 100% more males. Notes are provided on some of the species taken.