Flies can cause hassles at production facilities, says John Stewart, technical training manager at Pelsis Group – (c) Robert Spriggs_Shutterstock
Infestations of flying insects in production environments can affect the overall hygiene and cleanliness of an operation. Here’s how facilities managers can ensure their premises stay free of flying insects.
1. Monitor fly activity
Fly killers supply insight into the pest activity of a building, which should be checked regularly for the number of insects caught and what species they have caught. The correct identification is key to understanding where to find the breeding site, what it is feeding on, how to treat it and how best to monitor for future activity.
For example, if fruit flies are breeding in organic material in the sink waste pipes, understanding the biology of the insects will help you identify breeding sites and eliminate it.
Disconnect the sink trap and overflow then clean with a large bottle brush to remove the gelatinous biofilm. This is how to get rid of the larvae. Using cleaning agents alone will not suffice.
2. Prevent ingress of insects
Exclusion is the best form of prevention for insects. Placing fly screens on doors, windows, chain link curtains, air curtains and strip curtains can prevent pests from entering. The use of fly screens also allows for ventilation and helps to comply with the General/Food Hygiene Regulations 2004 & 2006.
It is important to get a company to perform a proper survey of the doors and windows that are to be screened. The doors should be manufactured to fit the doors and windows on the site. Kits are available that can be built on site, but these tend not to last very long due to poor construction.
3. Reduce breeding sites
Limiting food sources, such as overripe fruit left in a communal kitchen, plants being overwatered in offices leading to fungus gnats becoming a problem, and improper disposal of food waste leading to a house fly issue, is an effective pest management strategy.
4. Regular cleaning and maintenance
Cleaning of a site must be frequent, as in a clean-as-you-go policy with a weekly deep clean. There must also be good building maintenance, such as having walls and floors free of cracks to limit harbourage locations for pests.
However, water and debris will get trapped in cracks, providing an ideal breeding site for some fly species. Internal drains in food processing factories with traps should be cleaned and disinfected daily to prevent infestations, and waste bins should also be situated well away from the building to prevent breeding sites.
The bins should be washed and cleaned each time they are emptied to prevent the build-up of liquid and semiliquid residue build-up. The base of the bin should also have a drainage bung, however, if this is missing then rats can gain access to food stuffs.
5. Maintain landscaping
Vegetation and ornamental shrubbery in close proximity to the building may encourage plant parasitic insects and, in turn, predatory insects that will consume them, such as garden ants.
Lasius niger will be attracted to plants with aphids feeding on them. The ants protect the aphids and gather the honey dew excreted from the abdomen. Having large numbers of ant colonies around the building will encourage internal ant activity. Ants by their habits will enter bins and transfer pathogenic bacteria across food preparation surfaces, and contaminate products.
Most landscaping is placed for aesthetic reasons and poor maintenance and using the wrong types of plants are common. Pest control professionals should be consulted regarding the correct species of plants and placement, and as a rule of thumb it should be sparse and slow-growing to allow inspection for rodents. Sodden wet ground will also encourage fly activity, so areas where drainage is poor should have field drainage installed.
7. Reconsider external lighting
Lights should not be attached to the building fabric where possible as this will encourage night flying insects to the building.
External lights should be mounted on lampposts directed towards the building around 50 to 60 metres from the building. The type of external lighting can make a significant difference to the insect attraction to the building.
Mosquitoes, Culicoides midges and sand flies have generally been found to be attracted in higher numbers by short wavelengths, such as UV, blue (450–495 nm) and green (495–570 nm). Warm, yellow and orange lighting is widely believed to be less attractive to most species of flying insects than cold blue and green colours.
Bright white lights (spotlights), UV, or mercury vapour lights attract insects; they may be placed 50 to 60 metres from buildings to attract some pests away from the structures themselves or to intercept incoming insects. Lights away from buildings can be blocked in the direction from which insects typically come, and the light can be directed toward important building zones to minimise attracted pests thus not compromising safety and security.
John Stewart, technical training manager at Pelsis Group
