RESIDENCES,STRUCTURES
AND
COMMUNITIES
RESIDENCES,
The information and recommendations in this newsletter are applicable to
North Carolina and may not apply in other areas.
If you live in the mountains or the Piedmont region of North Carolina and you are bothered by small flies, chances are that they are black flies. Black flies breed in flowing water, such as creeks and streams. The larvae attached to rocks, aquatic vegetation, or woody debris. Bacteria and organic material that are filtered from the water by large fan-like structures are used as food. Black flies begin to emerge in April and continue throughout the summer depending on water temperature. In the Piedmont, emergence ceases in July in small streams, but in rivers black flies will continue to emerge into August and September. Some species of black flies will readily attack people, while other species of flies are attracted to people but only fly around the face.
A bacterial larvicide, Bacillus thurengiensis var. israelensis, can be used to control black fly larvae. When applied as a "slug" treatment, control of larvae can be achieved 1/4 to 1/2 mile down stream. Repeated treatments will be needed to reduce adult populations below nuisance thresholds. A treatment protocol for black flies is available on request. Needless to say, biting flies (adults and larvae) should be collected and identified before any treatment procedures are recommended.
Mosquito problems with vary as usual. Currently in flood plain areas adjoining rivers, particularly in the mountains, there are several species of mosquitoes that are out in high numbers. Local (individual homeowner) control is not really effective or possible because these insects can fly significant distances from breeding sites in search of blood meals. Fortunately, these mosquitoes have one generation per year and their populations should dwindle over the next few weeks.
On the other hand, asian tiger mosquito populations will become more noticeable, particularly in residential areas and particularly if the periodic rain showers continue. Again, pesticide spraying by individual homeowners is a waste time, money and pesticide. The best approach is habitat modification (or elimination). Remember that asian tiger mosquito breeds in places that fill rainwater. NOW is the time to look around your property for areas that collect rainwater, e.g., clogged drainage ditches, deep tire ruts, and low lying areas in fields are among the common breeding places. Try to improve drainage in these areas (or fill in ruts). Then there are all of those artificial breeding sites -- old tires, empty cans, canoes (and small boats) stored upright and uncovered, tarps covering boats or other objects, bird baths and even potted plants (the dishes underneath them). Empty the water, flush out birdbaths with fresh water, and discard junk on the property. It is a good idea to turn this into a neighborhood or community project. In ornamental fish ponds or aquatic gardens, the Mosquito Dunks containing Bacillus thuringiensis (B.t.), available at many retail outlets, can be used.
Regarding the use of repellents, we strongly recommend very
conservative use on children and pregnant woman.
Web page last updated on June 8, 1998 by Stephen J. Toth, Jr..