OCR Text |
Show 192 which may be inflicted even through summer clothing, lacerate the skin and produce a painful wound which may be irritating for hours or days. In addition, they are important as incriminated vectors of disease. Franoisoella tularensis causes tularemia, a disease of man and animals. Several cases of ulcero- glandular type of tularemia in man have resulted from bites of infected deer flies near the Great Salt Lake. Deer flies and horse flies are strong fliers and the females forage for a blood meal miles from their breeding sites. The females follow potential hosts for great distances. They feed only during daylight and are less active as wind velocity increases. Eight species of tabanids have been reported in the areas as the result of a study reported by Rees and Knudsen ( 1969): Chrysops disoalis Will.; Hybomitra sonornensis Osten Sacken; Tabanus punctifer Osten Sacken; Tabanus productus Hine; Tabanus Similis Macquart; Chrysops aestuan van der Wulp; Chrysops fulvaster Osten Sacken; and Atylotus incisuralis ( Macq.). There may also be other species present. Of these eight species, Chrysops d'isca'lis, the winged deer fly, is the most abundant pest and principal vector of the tularemis pathegen. The horse fly, Hybomitra sonornensis, is second in number and importance. Tabanid Control Tabanids in all stages are destroyed by numerous predators and parasites. Birds have been found to feed on tabanids, destroying great numbers of immatures and adults. The populations of C. disoal'is and H. ponornensis vary but remain sufficiently high to require applied control on the marshes near the Lake. |