Ponds make the ideal environment for various living animals. Some of these animals are welcomed guests while some are annoying insects. Gnats are among the more annoying guests that will use your pond to maximize their numbers. Before you can rid your pond of those nuisances, you have to first identify which sort of gnat you are coping with.
Biting Midges
Biting midges measures between 1 and 3 millimeters long with a grayish body that develops a reddish hue after feeding. The adult biting midge lays its eggs in water or on moist surfaces. Two to seven days later, the eggs hatch and worm or caterpillarlike larvae emerge. The larval phase takes anywhere from two weeks to a year to grow into the pupa stage, which lasts two to three times. Both the female and male adult midge feed on nectar. The female adult midge, nevertheless, also absorbs the blood of humans, domesticated animals, wildlife and livestock. Though small, the bite of the midge is debilitating and produces a burning, itching bump. Biting midges transmit the livestock disease blue tongue, which can destroy the infected livestock.
Nonbiting Midges
Nonbiting midges have a look similar to a little mosquito but do not bite humans, mammals or livestock. These annoying insects lay their eggs on the surface of various bodies of water, including streams, ditches and ponds. Their eggs sink to the bottom, where they hatch in a few days. The nonbiting midge larva creates tunnels in the mud in which it lives underwater consuming organic matter. After two to seven weeks, the larvae transform into a pupa that — after three days — will swim to the surface to emerge as an adult. Nonbiting midges have a few beneficial aspects such as being a food source for fish and consuming organic matter to maintain the pond clean.
Buffalo Gnats
Buffalo gnats — also called black bows — commonly feed on livestock and birds but have been known to bite humans too. The adult buffalo gnat is black with a humpbacklike look. The female attaches its eggs to plants or rocks underwater. Once hatched, the larvae will pupate underwater until it emerges as an adult many weeks later. Buffalo gnats require running water and therefore are generally not found in ponds unless the pond includes a water feature — such as a waterfall — that maintains the water flowing.
Deer Flies and Horse Flies
Deer flies possess a grayish to brown-colored, patterned body and produce painful bites that can draw bloodcirculation Adult deer flies normally only live for about three weeks and will lay their eggs on aquatic vegetation or grasses growing at the edge of slopes. After the eggs hatch, the deer fly larvae develop in the muddy place feeding on the decaying plant matter. Deer flies utilize the plants growing close to the pond to rest on. Horse flies are a little larger than deer flies, switching between 3/4 and one inch long. Despite their title, horse flies are not confined to feeding on just horses. They will bite humans and other mammals too. Horse flies lay their eggs on plants that hang over ponds and if the eggs hatch, the horse fly larvae falls to the muddy dirt burrowing itself. The horse fly larvae feed on snails, plant debris, earthworms and other larvae.
Control
Based on the species, controlling gnats on your pond could be a bit difficult. One choice to controlling nonbiting midges would be to add predatory fish — such as carp or catfish — to the pond. These fish will absorb the larvae. The bacterium Bacillus thuringiensis var. Israelensis — when implemented into the water and surrounding soil — will control the larval stages of various kinds of gnats and mosquitoes, including buffalo gnats, nonbiting midges and biting midges. This soil-borne bacterium is safe to use in ponds and — if used in accordance with the manufacturer’s directions — generally wo not harm fish, birds or other wildlife. Another option is to pull dragonflies and damselflies to the pond. Both the larval and adult phase of the predatory insects will prey on gnats, midges, flies and mosquitoes. Adding floating, submerged and marginal aquatic plants in and around the pond will offer the ideal environment for dragonflies and damselflies.