Reliability of Trapping in Determining the Emergence Period and Sex Ratio of the Sugar-beet Root Maggot Tetanops myopaeformis (Röder) (Diptera: Otitidae)

The sugar-beet root magsot, Tetanops myopaeformis (Röder), is one of the most important pests of sugar-beets in southern Alberta. From 1956 to 1960 studies were made of various phases of its life history (unpublished). In this paper, napping adults of T. myopaeformis by insecticide and water traps is judged for reliahility in determining dates of emergence and sex ratio when compared with data obtained from emergence cages in the field. Information is also given on the influence of color and a wetting agent on the number of flies caught in water traps.