Control Test of Horse Flies (Tabanidae) in the Race Course

II . Collecting Test of Horse Flies by an Improved Trap (Equine Health Laboratory Trap)

Abstract

Previously the authors reported that favorable results had been obtained from a collecting test of horse flies by using a trap remodeled partially from Kitaoka's and Shinohara's traps in 1968. In 1969, a newly improved trap, or the Equine Health Laboratory (EHL) trap was made by referring to the results obtained in the previous year (Figs. 1 and 2). Then, collecting tests of horse flies were performed by the EHL trap in the Niigata Race Course and the Joban Branch of the Equine Health Laboratory. The results obtained are as follows. 1) Over a period from July 24 to August 21, 5, 276 horse flies were col lected by 10 EHL traps in the Niigata Race Course. Over a period from August 1 to 28, 6, 445 horse flies were caught by 7 EHL traps in the Joban Branch. Although the numbers of collected horse flies were related to the growth of horse flies in the habitat, it was recognized that the EHL trap had a very excellent effect on the collection of horse flies, taking the results mentioned above and Hayakawa's report2) into consideration. 2) Traps were installed at the following three sites. Site A was in a very wide place without obstacles near stable, race track, or wet low zone. Site B was in a relatively narrow place near the same place as site A. Site C was in a very narrow place among trees and houses. Then, a trap installed at A was found to have a more excellent effect than one at B or C. A trap at C gave a worse effect than any other. 3) It is considered from the results of the present test that at least one trap should be installed in two hectares of the controling area of horse flies.