Flying Insects - Flies & Wasps

Flying insects - Preferred Breeding Ground

Image of a Fly, Flying Insects, Fly Control by Aderyn

Musca domestica (Housefly) - rubbish tips, moist foods, damp mops.

Fannia canicurlaris (Lesser Housefly) - semi-liquid decaying organic matter.

Culicidae (Midges and Mosquitoes) - requires water for larval and purpae stages.

Pollenia rudis (Cluster Fly) - eggs in soil, larval and purpae stages in earthworms. Adults cluster in roof spaces in autumn.

Calliphoridae (Blow Flies, Blue and Green bottles) - meat products, dead animals including rodetns.

Drosophila spp (Fruit Flies) - fermenting vegetable matter.

Psychodidae (Filter Flies) - sewage, wet, rotting material.

Ceratopogonidae (Biting Midges) - damp soil, boggy areas.

Control of Fly Infestation

Identify the species
Locate the breeding sites
Instigate removal of breeding sites
Insecticidal control measures
Use of Electric Fly Killers
Adults can sometimes be controlled by treatment with fogs or smokes
Identification of species will guide you to likely breeding sites. Adults can be prevented from entering premises via screening off
Find breeding sites if possible and remove. Virtually impossible in poultry houses but it has been achieved in intensive animal breeding stations. Locating where adults congregate may lead to nearby breeding site. Look for fly marks on light and alighting surfaces
Larval food must be moist so look for areas where this accumulates e.e. drainage channels, under equipment. Anywehre where waste food tends to accumulate. Is there a soggy residue in the base of bins? Look in residues for larvae
Encourage removal of breeding sites as a priority. Treat alighting and breeding sites with insecticides. For large numbers of flying insects use Microgen. Sprays of dust are useful in treatment of refuse

Control of Wasps

Wasps (Vespula species) belong to the same order of insects as Ants (the Hymenoptera). They are a highly evolved order of insects with a caste system, where workers (sterile females) build the nests, raise the young and forage for food under the direction of the queen wasp.

All pest wasps have a narrow waist which gives the abdomen great mobility, elbowed antennae, mouthparts with powerful mandibles and fore and hind wings, linked by minute. They also have a characteristic black and yellow colour and the ovipositor is modified to form a sting.

Image of a Wasp, Flying Insects, Wasp Control by Aderyn

The Importance of the Control of Wasps

Prevention of contamination e.g. wasps in food products.
Loss of goodwill. Adverse publicity due to prosecution or the prescence of wasps in restaurants etc.
Prosecution for selling contaminated foodstuffs.
Discontent. Staff working in presmises infested by wasps are agitated by them.
Fear and discomfort. Wasps stings are unpleasant and painful and can be dangerous, especially to susceptible people.

There are two common wasp species, Vespula vulgaris (The Common Wasp) and Vesppula germanica (the German Wasp). Both species prefer to form their nest or colony in the ground, but become pests when they nest in caves, outhouses and cavity walls. Wasps also achieve pest status when they forage for food around waste containers and manufaturing areas of confectionery and preserve factories and cake shops.

Wasp Life Cycle

A single fertilised female or 'queen' begins each colony in the spring. Having mated the previous autumn she emerges from her winter hiding place and seeks a suitable site or nest. This is usually in April, depending upon the weather conditions. The queen scrapes shavings of wood from fence posts, dead trees etc. and chews them to make 'wasp paper'. The wood fragments bound together with adhesive saliva frm a thin but strong paper when dry.

The female begins her nest with a few hexagonal cells suspended at the end of a small stalk or pedestal attached to a ceiling or surface. Over this is an umbrella-like cover.

Side view through a wasp nest, Wasp Control by Aderyn

The queen lays her eggs, one in each of these cels. They hatch in 3-5 days. When the larvae emerges she feeds them with fragments of insects she has captured. The life cycle from egg to adult takes between 3 and 4 weeks.

The next generation emerges as sterile workers who take over the work of nest building and food gathering. New cells are formed in a horizontal layer of "comb". When this has reached a certain size a similar layer is constructed, suspended from the preceding layer by short columns of stalks. Six or seven "combs" may be formed and covered by an evelope of paper.

The shape of the nests varies and each cell may be used tow or three times. An average nest may produce 25,000 - 30,000 wasps during the season.

In the summer months special large cells are constructed, containing the larvae destined to become "queens". At the end of the summer the "queen" lays unfertilised eggs. Some workers also reproduce without fferilisation. These unfertilised eggs all develop into makes and mate with the young "queens". Fertilised young "queens" fly away to find a resting-place to hibernate. The rest of the colony dies out in autumn. The nest is never re-used the next year.