OCR Text |
Show 186 caught in the eye, or crawl into the ear channel." ( Hansen, 1969) Adult brine flies are widely distributed on the Lake but are more concentrated in certain areas. Figure 27 shows the location of reefs producing brine flies. Wind direction and velocity seem to have a direct affect on their distribution. They first appear in April and continue to late September. The population peak is during' July and August with a decrease in numbers as daily temperatures drop. ( Vorhies, 1917) The tremendous number of brine flies produced in the Great Salt Lake is attributed to a response to a simple ecological law: a species thrives when there is an abundance of food consisting basically of a few species but great numbers ( algae and bacteria), competition of a limited number of species ( one brine shrimp and two brine flies), reproduction unhindered by competition from other animals competing for food or living space, and few natural enemies ( Wirth, 1970). In addition to being a great source of annoyance to man, the brine flies play a very important role in the ecosystem of the Lake and vicinity. In the water, they eat great quantities of algae, bacteria and organic refuse from brine shrimp and their own life processes that could become more abundant and objectionable than the brine flies themselves if they were completely destroyed. The brine flies are also a major source of food for bird life associated with the Lake and many land animals inhabiting the shores of the Lake. Brine Fly Control Natural control by unfavorable physical conditions, predators and parasites is apparently inadequate to reduce the population to numbers |