Flying insect identification guide

Use our handy guide to help you identify your customers' flying insect problems, select appropriate products and service solutions, and analyse your fly catch.

Need assistance with fly identification? Our technical team are on hand to offer a full insect identification service. Call 0800 988 5359 or email customercare@pelsis.com to find out more.

© All images copyright of Peter Meaney, Harvard Pest Consultancy

 

COMMON HOUSE FLY (Musca domestica)

 

Identification

6mm long, wingspan of 10mm, grey/black chequered abdomen which is slightly hairy, blackish stripes on thorax, distance between eyes wide in female and narrow in male, vein bends sharply before reaching edge of wing. At rest wings are spread. Larvae are white and opaque and pointed.

 

Habitat and breeding

This fly is found around dustbins, compactors and where there are poor hygiene practices. Up to 150 eggs, each 1mm long, laid in batches at a time in the selected foodstuffs and larvae starts putrefaction that is spread by the adults with bacteria on their bodies. Up to five batches are laid in their lifetime, larvae (maggots) hatch in eight to 48 hours and are 1mm long depending on temperature. The larvae have three moults and reach 12mm in length. The larva then travels some distance to pupate and will crawl up smooth surfaces if moist. It prefers to pupate in the soil and buries itself 7cm-60cm depending on the medium. The larval skin is cast turning into a puparium, this is 5mm-6mm long. The adult fly hatches three to four weeks later. The fly lives for 25-52 days and is found from April to November normally. 

Control

The presence of this fly is always an indicator of a proofing defect and possibly a hygiene problem. Flykillers can be sited to catch insects that have breached barrier methods employed, but they should not be used as the first line in defence against flies. Insecticidal spray treatment should only be employed to alighting surfaces, door and window frames but no surface coming into contact with food. Treat bin areas with a residual insecticide after cleaning. Improvements in general hygiene will be necessary. All Insect-O-Cutor flykillers are highly effective at controlling the common house fly. 

LESSER HOUSE FLY (Fannia canicularius)

 

Identification

Slightly smaller than the common house fly, 5-6mm long with a 12mm wingspan, grey thorax with three longitudinal stripes, extensive yellow patch at base of abdomen, at rest wings are folded along back, venation shows fourth vein extending straight to wing margin. The larvae is dull grey-brown and is fairly flat with feathery growths.

 

Habitat and breeding

These flies mainly breed in poultry manure which the farmers spread on the fields from poultry houses seasonally, this is the reason why numbers of adult flies are found in or around factories and properties if located in a rural area. Approx. 50 eggs are laid in batches when female is ten days old, they are 1mm in length they hatch in 24-48 hours, larval development eight days and three skin moults, larvae 6mm when full grown, egg to adult normally three weeks. The pupae stage lasts from one to four weeks.

Control

The presence of this fly is always an indicator of a proofing defect and possibly a hygiene problem. The main control measures are as follows: Treatment for this species is not the same as the house fly - this insect is associated with poultry and animal houses and is less attracted to ultra violet irradiance than in the same way as its cousin. Exclusion is the best method of control but spray treatments with residual insecticide to any alighting areas can be carried out after the removal of food spillages. Compactor areas and waste assembly sections need to be scrutinised. Insect-O-Cutor flykillers can form an important part in the control of the lesser house fly as part of an IPM programme.

CLUSTER FLY (Pollenia rudis)

 

Identification

6mm long, wingspan 10mm, a largish fly with a distinctive bristly yellowish and black marked abdomen, the thorax is covered with yellow-gold hairs, large reddish compound eyes.

 

Habitat and breeding

Cluster flies are most commonly encountered around September/October, when they come indoors seeking harbourage. South west and mainly south facing buildings are favoured; the flies will invade cladded buildings and silos, and will enter roof spaces and voids via small gaps and crevices in the fabric. They will cluster on the exterior of buildings in huge numbers prior to crawling into the harbourages. In the spring the warmth revives them and they start to leave buildings in numbers. Eggs laid loosely on damp soil and in leaf litter, larvae hatch after a week and seek out earthworms, they bore through the wall of the victim’s body. After it has grown to full size it bores its way out of the worm and pupates in the soil. Depending on the weather two generations are normal but up to four are possible, flies hatch from the pupae and live outdoors; they start to enter buildings in large numbers in late September onwards into November when the temperature begins to fall.

Control

The best method of control is the proofing of a favoured building to keep them out, although this is seldom 100% effective a reduction in numbers might be achieved. If found in numbers in the loft space, treatment should be with a smoke generator placed on a heatproof surface. It is also worth remembering to ensure that the water tanks are sealed/covered, that there are no bats in residence in the roof space.In some situations it may be best to treat a localised area with a residual insecticide, vacuum up all accessible dead insects. A follow up visit may be necessary in the spring if the initial treatment was in the autumn, this is when survivors start to leave harbourages warmed by the sun, and re-infestation is reported. Entry is likely from the end of August to November and activity is likely when they exit from March to May. Insect-O-Cutor flykillers specifically designed for cluster flies, such as an Exocutor with optional cluster fly tray, can form a key part of an IPM approach to control. NB.Ensure that there are no bats present, which often can be found living in areas where cluster flies congregate.

FRUIT & VINEGAR FLIES (Drosophila spp)

 

Identification

2mm long, 3mm-4mm wingspan, fat bulbous body greyish yellow, some have large often red or orange eyes, simple wing venation, feathery antennae, cross-striped abdomen.

 

Habitat and breeding

Vinegar factories, breweries, wine producers, dried fruit washing plants, tomato processors, fruit/drink producers and warehouses where spillage has occurred or when stock has become damaged on pallets. Returned stock sometimes supports infestations. Found in bars around optics and where beer or soft drinks have been spilt or empty bottles stored in bins etc. 500 eggs laid at 20-25 per day in the foodstuff for the hatching larvae, larvae have three moults and they migrate to pupate. The egg to adult stage can be as short as eight days at 30°C.

Control

Control is achieved by the removal of their breeding medium and the food attraction source. Drains and gullies need to be kept clean of trapped material and dead spaces under mixers and provers in bakeries also need regular attention. Where found in fruit wash plants removal of trapped fermenting material will help in their control. In bars and kitchen areas, remove or cap all fruit juice bottles and similar attractive receptacles. Ensure improved hygiene around beer, fruit juice and other drinks dispensers. Misting will knockdown insects on the wing but residual spraying is not recommended. Screening windows can help with control. Glueboard Insect-O-Cutor flykillers are highly effective at controlling fruit flies and other small fly species.

FILTER / DRAIN FLIES (Psychoda spp)

 

Identification

Tiny flies up to 2mm long. Grey adults with hairy wings held roof-like over the body.

 

Habitat and breeding

When emergence takes place the flies can often be seen swarming on the drier parts of the filter bed walls. 200 eggs laid in batches on decaying and wet matter, particularly in drains, gullies or where sludge has been allowed to accumulate. Larvae live in this matter feeding until pupation. They have a siphon at the end of their bodies, which sometimes is seen breaking the surface film. The eggs take one to six days to hatch; the larvae grow from 1mm-9mm and develop from ten to 50 days according to temperature. There can be as many as eight generations per annum.

Control

This is often difficult to achieve, generally you should isolate plants likely to support the flies and ensure that they are in good order before being reintroduced. A plant specialist or horticulturist can carry out a treatment in the void below the plant. Sometimes extreme action has to be taken because of complaints and the area affected treated with a fog or mist using ULV insecticidal material. Residual spray treatment is not often effective. Glueboard Insect-O-Cutor flykillers form an important part of control as part of an IPM programme.

COMMON WASP (Vespula vulgaris)

 

Identification

10mm to 20mm, narrow waist, distinctive banding in bright yellow and black, two pairs of membranous wings. Both wasps are very similar to look at.

 

Habitat and breeding

Queen emerges from hibernation in mid-April, constructs 10-20 chambers and lays eggs in each one. Sterile female workers hatch and by late summer the colony reaches 3,000 to 30,000 individuals. Males and new queens are produced in late summer, males mate with the new queens and then die. The queen wasps in turn fly off to find an over winter hibernation site usually inside buildings or hollow trees.

Control

The primary control method is to locate nests on site and carrying out a treatment with a residual insecticide formulation, however control can be achieved by using the following methods: Proofing doors, windows and openings, with screens and curtains as appropriate; Cleaning spillage from a delivery point, e.g. syrup/sugar from intake pipes in a wall; All Insect-O-Cutor flykillers are highly effective at controlling the common wasp. For 'in food counter' control, use a specialist product such as the Insect-O-Cutor Nectar with food safe attractant.