Our 15 year-old house is infested with subterranean termites. We delayed treatment due to a report that there may be hazards in the use of chlordane. Are there other means of treatment of termites that avoid chlordane and still are effective? I have heard of an insecticide called methoprene which the Department of Agriculture suggests may be less toxic.
Thomas F. Carlisle Selma, Ore.
I'd recommend no further delay in eliminating those subterranean termite residents at your address. In my opinion, calling on duly licensed professional termite-control companies is the safest, most practical way to eliminate termites. These firms must use only government-approved insecticides.
''A structure with no heating system embedded in or under the floor, slab, can be treated effectively with chlordane, providing long-lasting protection and elimination of present infestations,'' says a director of the National Pest Control Association Inc. in Dunn Loring, Va.
''There are other termiticides. Dursban has been used as an alternative, but lacks the extended use in the industry that chlordane has.
''The pesticide methoprene is a growth regulator, and is registered only for flea and ant control. It has only been used experimentally on termites, and is not available.''
Note: When there are underslab heating systems, subterranean termite control is fussy but not impossible.
Concerning the professional application of insecticides, we received the following note from Sue Cotty, extension assistant at the College of Agriculture , Council for Environmental Studies, University of Arizona, Tucson.
''If applied correctly, an individual will not be adversely affected,'' she writes.
''The concern lies in the fact that these insecticides are fat-soluble and remain in the environment for many years. This persistent characteristic also makes them desirable for residual termite control.
''Clearly, one must weigh the risks involved with pesticide use vs. no control at all.''