A new Method of trapping Flies

Abstract

(1) An adhesive made from 3 or 4 parts (according to the temperature) of the coagulated latex of Carpodinus hirsuta and I part of either shea butter (from Butyrospermum parkii) or palm oil (from Elaeis guineënsis) was found to be very effective against both house-flies in kitchens and Stomoxys spp. in pig pens.(2) In kitchens, wires (diameter 4 mm.) were treated with the adhesive and suspended over the table on which food was prepared. The wires should be renewed every three or four days when flies are abundant and once a week when the infestation is light.(3) At Ibadan in 1943, house-flies were abundant from early March to late July; the maximum house-fly infestation of both kitchens and pig pens occurred during the second week of May. The upward trend in adult incidence first became evident in mid-February of both 1943 and 1944 and appeared to be correlated with a rise in temperature at that time.(4) Ten wires treated with adhesive were suspended under the eaves of each pig pen. Each pen consisted of a covered pen and an open yard divided by a half-wall; a screen made of oil palm fronds was erected above the half-wall with the object of making the innerpen sufficiently dark to deter flies from entering it. About half a million flies (about 27·5 per cent. Stomoxys spp.) were trapped in12 pens in a period of 112 weeks.(5) Stomoxys spp. (principally S. nigra, Macq.) were abundant between early June and mid-August in 1943 and between early June and late November in 1944. In 1943 there was a short dry season between 25th July and 12th September, whilst in 1944 there was no break in the rains. There is a marked correlation between rainfall and the incidence of S. nigra. Heavy rainfall soaks straw round the stock-yards, heaps of weeds, etc., which decompose and provide suitable media for larval development.