Larger biting flies such as tsetse, horse flies, deer flies and stable flies cannot pass through most consumer products sold as mosquito netting or insect screening. If these are the only insects one wishes to catch, then a wide-mesh is the preferred choice. A wide mesh provides minimal wind resistance, improving trap stability. Wide mesh also allows small, non-target insects to escape capture.  Capture of non-target species with fine mesh is a problem near cattle and silage (Phoridae, AAFC dairy). Similar problems may occur in other situations, e.g.  near lakes or rivers with seasonal emergences of midges (Chironomidae) or other insects.

In North America, insect screening is typically sold with mesh size of about 200+ holes per square inch. This mesh is  suitable for most nuisance insects, except for biting midges ("Noseeums", Ceratopogonidae, e.g. Culicoides). To retain these small species requires a very fine mesh (e.g. 600+ holes per square inch).

Retail and wholesale sources often change suppliers; similarly manufacturers are always improving their products. Subtle changes in the appearance of the netting may affect the catch in traps, e.g. as a function of the presence of fluorescent brighteners, ultraviolet protectants, or changes in texture (shininess). Mesh sizes may also change with time in response to market demand or process-driven changes at the textile mill.

An important example of evolution of useful products is the netting adopted by many researchers in Africa for tsetse traps in the mid-1990's (VF or Vestergaard Frandsen, Denmark). This former VF product is now quite different and is used for insecticide-impregnated mosquito bed nets (Permanet ® 2.0). Impregnated netting (synthetic pyrethroids incorporated into polyethylene or polyester) is now being produced on a very large-scale for malaria control (World Health Organisation), but these special materials are not yet readily-available to the consumer.  Products that have obtained full or interim approval from WHO are  Olyset ®, Permanet ® 2.0 and Interceptor ®. See the WHO Pesticide Evaluation Scheme (WHOPES) for up-to-date information.