No see ums are a species of fly that get their common name from their tiny size and from the fact that most people cannot see them. Other common names, like sand fly or biting midges, come from the fact that they are considered a major pest in coastal areas and because they are parasitic insects. They are considered a severe nuisance pest because of their painful bites. No see ums can also be vectors of disease in livestock. Even though no see ums are found throughout Canada and the United States, they primarily infest coastal areas, waterways and other areas that are near large bodies of water.>> Read More
Adult no see ums are generally 1 – 3 mm in size. Some may be slender but usually, their shape is robust. They are dark in color and sometimes, even some areas of their wings are shaded into a dark color. When no see ums are at rest, their wings are flattened over their body. No see ums have fairly long and slender legs and also obtain multi – segmented antennae.
There are several similar species of flies. They are often times confused for each other or misidentified. Some of these similar groups of flies are midges, black flies and mosquitoes. Physical attributes, resemblance in shape and size and similar biological habits may be reasons why they are often times incorrectly identified.
Female no see ums lay their eggs in batches that vary in egg count from about 30 eggs to 40 eggs. Sometimes, they may have huge batches that have an egg count of up to 450 eggs in just one batch. A unique characteristic of this species of fly is that larvae burrow in the soil. Some of the areas that the larvae burrow in are coastal and inland beaches or very dry areas. Some species actually make use of the period of seasonal rains and the dry spells in between those rainy seasons. They burrow in the soil as it dries out and resume the rest of their development as the seasonal rains begin. There are some species that do not need dry soil to burrow in and are able to burrow in moist soil and are even fully aquatic. The larval stage takes about anywhere from about 3 weeks to even 2 years to complete. However, despite their long larval period, their pupa stage is very short. The color of the pupa will range anywhere between a pale yellow to a dark brown and the pupa stage only lasts about 5 – 10 days. After they emerge as fully mature adults, they immediately begin to feed and reproduce and will only live for a few days. The only difference between males and females besides physical attributes is that females typically require a blood meal before they are able to lay their eggs.
In some of the more temperate regions or northern regions of the country, no see um activity begins early in the spring and ends near the end of the summer season around late June. However, the more tropical the area is, the longer the adult activity lasts. In some of the southern regions like Southern Florida, Texas, or California, no see um activity is virtually active all year long. The times during the day that no see ums are active will vary between species. For instance, some species are just active during sunset and other species are active at both sunrise and sunset. Other species are active during the daytime whereas others are nocturnal and only active during the night.
The preference of their food source will also vary between species and even sexes. Most female no see ums require a blood meal before they are able to lay eggs, however, males are not required to feed on blood before they mate. Both sexes will feed on nectar and in some species of no see ums, males do not feed at all. Some species of no see ums feed on the blood of large animals like mammals and birds, including humans. Other species may only feed on the blood of larger insects like dragonflies or moths.
Many species of the no see um flies will gather in swarms during mating season. Therefore, some people may describe their experience with no see ums as witnessing a large black cloud above water or over a bush. There are a few species that do not fly or “dance” before mating and will mate on a substrate, like the ground.
The main reason why no see ums are considered such a severe nuisance pest is because of the pain that they inflict as they bite to feed. They’re mouth parts are very different to their cousin mosquitoes. Rather than a needle – like, sucking mouthpart that mosquitoes possess, no see ums have saw – like, biting mouthparts, which causes a sharp pain as they pierce the skin. The itching sensation is intense and will last for several days. Many people are surprised to find that the aftermath of their bite is on a much larger scale than their actual physical size. They are also very avid and persistent feeders, which is often times extremely aggravating and tormenting.
To get rid of a no see um infestation, mechanical control in conjunction with a chemical control, will provide the most complete system of removal. Also, both indoor and outdoor control is required to gain a complete control over no see ums. Indoor control will mainly consist of mechanical control with little chemical control and outdoor control will consist of habitat modification in conjunction with mechanical and chemical control. Due to their small size, no see ums can fit through most standard screens. A fine mesh screening is available to keep no see ums out of structures. Replace window screens and door screens as necessary. In commercial areas, air curtains may prove to be effective for exclusion. Outdoors, habitat modification may need to take place to maintain low levels of no see um populations. Such things as keeping water levels at least 2 – 3 inches above mud surfaces at all times will be crucial. By avoiding dry spells, you will eliminate breeding sites for no see ums and ultimately, prevent future infestations. Properly labeled liquid concentrate insecticides that are microencapsulated can be applied to surfaces around the structure to create a barrier. By focusing on windows, door frames and other possible points of entry, a liquid insecticide barrier is applied to prevent an infestation from invading indoors.