Ivan B. Gluckman of Reston thinks it's time that Fairfax County faced the gnat problem. So does County Executive Leonard Whorton.

When they meet next Monday, the Fairfax County Board of Supervisors will get a sheaf of documents detailing what Gluckman calls the "plague of gnats that infects this part of the county".

Gnats, or black flies, are small insects that divebomb people's eyes, noses, ears, and limbs. If the attacker is a female, she sucks blood. Recorded history produces lamentations about gnats dating back to the 5th century.

Fairfax Supervisor Martha V. Pennino (D.Centreville) in response to Gluckman's plea has asked Whorton what could be done to control the gnats.

Not surprisingly, the Fairfax County staff proposed a study. The memo sent to Mrs Pennino and the other supervisors estimated the study would cost about $10,000 and the last two years. It is needed to identify the exact species and breeding site of gnats before controls can be undertaken, the memo said.

The solution, in the language of entomologists, is larvicide, or killing the gnats in their earliest stage of development.

Because gnats apparently breed in the Potomac River from Great Falls to a considerable distance upstream, the water would have to be dosed with a poison, organophosphate, which is used to control mosquitos.

But this would involve getting an approval from the State Water Control Board and the federal Environmental Protection Agency because the Potomac is a source of drinking water for more than 2 million people in metropolitian Washington.

Such a solution seems to be doubleful, S.G.McCausland, an entomologist with the Virgina Health Deparment said in a letter last month to John Clayton, the county's director of environmental health: ". . . Unless the nuisance factor were extremely high or black fly (transmitted) diesease became important, the cost of control is probably prohibitive at this time".

Fairfax residents may be forced back to traditional remidies. These range from wearing wide-brimmed hats to using insect repellents, although they are only marginally effectivee, according to Dr. Richard K. Miller, director of county health services. "There is no permanent solution to the gnat problem in the Washington area".

Nevertheless, Gluckman, thinks efforts should go forward. "The value of living in Fairfax County is greatly diminished" because of gnats, Gluckman wrote recently in a letter to the Reston Times.