Aventis Environmental Science

Houseflies

Description

Order: Diptera (‘two-winged’) Characteristics: Single pair of membranous wings; hindwings modified as ; suctorial mouthparts, piercing or non-piercing; large compound eyes; tarsi, 5-segmented; metamorphosis complete with egg, larval, pupal and adult stages. Common 14mm wingspan Family:

Species characteristics: liquefy food by regurgitating digestive Common Housefly (Musca domestica) Distribution Common (M. domestica) are juices and their stomach contents on to the Adults, 6-8mm long with 13-15mm wingspan; ubiquitous , with a flight range of at least food substance. This ‘liquid’ is then drawn up by grey with 4 longitudinal dark stripes; 8 kilometres (5 miles). They are highly active the suctorial mouthparts and in so doing the basal half of abdomen buff-coloured and indoors. In colder climates breeding generally insects pick up pathogenic organisms, which occasionally transparent at sides, with central ceases before winter, whereupon the insects may collect on their bodies to be transferred on dark band broadening to cover last abdominal overwinter either as pupae or adults. However, contact with other surfaces or survive passage segments; at rest, wings are spread; venation in warm environments houseflies remain active through the gut to be deposited as spots. Fly shows a sharp upward bend of 4th vein at apical and reproduce throughout the year. spotting, produced when the feeds or end. defecates, results in rejection of contaminated Lesser houseflies (F. canicularis) are frequently farm produce, for example eggs, at point of sale. Lesser Housefly (Fannia canicularis) encountered in poultry houses. They have an Furthermore, flies are frequently the subject of Adults, 6mm long with 12mm wingspan; grey erratic flight pattern and are often seen flying in complaints to environmental health authorities, thorax with 3 longitudinal stripes, less large numbers around indoor light fittings. The causing major problems where infestations over- pronounced than those of Common housefly; Lesser housefly is more tolerant of cool spill from breeding sites such as rubbish tips extensive yellow patch at base of abdomen; at conditions than the Common housefly. This and animal houses. rest, wings are folded along back; venation species survives the winter mainly in the form of shows 4th vein extending straight to wing pupae, although, as with the Common housefly, The Lesser housefly makes longer flights and margin. adults remain active and reproduce throughout spends less time resting than the Common the year in warm conditions. housefly. Females of the species tend to remain near the breeding sites and only the males Significance migrate. For these reasons F. canicularis is less Houseflies can transmit intestinal worms, or prone to transmit disease than M. domestica, their eggs, and are potential vectors of diseases but large populations and similar feeding habits such as dysentery, gastroenteritis, typhoid, mean that this insect, too, has a considerable cholera and tuberculosis. They will frequent and potential to act as a vector of disease. It has feed indiscriminately on any liquefiable solid occasionally been implicated as a vector of food, which may equally be moist, putrefying intestinal or urinary myiasis. material or food stored for human consumption.

Lesser Housefly 12mm wingspan Life-Cycle Control Common Housefly Flies have rapid, prolific breeding habits and Forty-eight hours after emergence as an adult, high mobility. In order to break the life-cycle, the female commences egg laying. During her control measures should be directed against adult life of 1-3 months she is capable of larval and adult flies. producing 4-5 batches of 100-150 eggs. The pearly-white cylindrical eggs, 1mm in length, a) Hygiene/management are laid in moist decaying matter such as Satisfactory hygiene is necessary to limit household refuse, compost or dung. The eggs potential breeding sites and food sources. hatch in 8-48 hours, giving the smooth, white, legless maggot larvae. These burrow away from Domestic refuse: this must be stored in well light, seeking an optimal temperature of 21- sealed bins, for early removal to disposal sites. 32°C, and after 3 moults reach maturity at a High-risk material should be sealed in bags and length of 10-12mm. burnt wherever possible. Refuse tips should be covered with earth, to a depth of at least In the summer larval development may be 230mm (9 inches), and then compacted. This completed within a few days, but in winter this will minimise larval emergence and promote process may take more than a month. When fermentation temperatures at which larvae mature, the larvae leave the breeding site for cannot survive. the cooler surrounding areas; e.g. soil. Here they develop as yellow, brown or black pupae 6mm Farm manure: manure should be kept as dry as long. Depending upon conditions, adults possible, especially in poultry houses, where emerge 3 days to 4 weeks later. The full cycle is leaking water feeders can provide ideal, moist generally completed between one and 4 weeks, breeding conditions. The Biothermic method of depending upon temperature. storing dung involves compacting manure into a cuboid stack, a method particularly suited to It is clear that there is considerable potential for horse manure. This form of storage promotes the development of huge populations. Under uniform, persistent fermentation throughout the temperate conditions as many as 12 generations dung, which is lethal to larvae. Tarpaulins can of flies may breed in one season whilst under also be used to cover heaps, in order to prevent tropical conditions even this rate of egg laying and conserve the heat of reproduction will be exceeded. fermentation.

Lesser Housefly Entry of adult flies into buildings can be Lesser houseflies are prolific breeders in poultry prevented by 1.18mm-mesh fly-screens (which manure, but will also breed in other moist can easily be removed for cleaning), air curtains, decaying matter. Egg laying commences when bead screens or self-closing doors equipped with the female is 10 days old. The eggs are banana- rubber flaps. Glossary of terms shaped, 1mm in length and bear a pair of Halteres: Club-shaped balancing organs. longitudinal ridges which assist flotation in a b) Physical control using maggot traps Suctorial: Capable of sucking. liquid medium. The flattened, legless, grey- Maggot traps take advantage of the fact that Tarsus (Tarsi): Apical section of leg (the foot). brown maggots hatch within 24-48 hours. Hairy larvae need to migrate from breeding sites to protuberances on their dorsal surface are cooler surroundings in order to pupate. A simple thought to aid progression and floating in a trap consists of a concrete platform, on which Advice semi-liquid medium. The newly hatched larvae manure or refuse is stored, surrounded by a Aventis has an extensive range of products frequently wander for a time before burrowing water-filled moat in which migrating larvae are specifically formulated for the control of flying into a suitable food. Larval development trapped. and crawling insect pests. requires a minimum period of 8 days, during which time the larva passes through 3 stages, c) Insecticides Further information on all Aventis eventually attaining a length of 6mm. Pupation In order to obtain the best results, insecticidal Environmental Science professional pest control requires a drier location and lasts for at least 10 control measures should be integrated with products is available from: days. Development from egg to adult good hygiene. Aventis Environmental Science emergence takes 3 weeks, although cooler Fyfield Road, Ongar, Essex, CM5 0HW conditions prolong this period. United Kingdom Tel: +44 1277 301116 Fax: +44 1277 301119

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