Pest guests: How to fend off flies and other unwelcome critters

By Alice Sinia

Flies are the most frequently encountered pest at restaurants. According to survey findings released by Orkin, half of restaurant patrons reported a pest sighting in the past year, and 95 per cent of those included flies. While they may not seem as threatening as wasps, flies can carry twice as many disease-causing pathogens as cockroaches.

The summer months will only turn up the heat on pest pressures, even on the patio. Though outdoors, pests on the patio can still make customers think twice about visiting your restaurant again. They can lead to negative online reviews, less-than-stellar media coverage or even a failed health inspection. Toronto Public Health classifies pest infestation as a crucial infraction, only one of which can lead to the immediate shutdown of a restaurant. The same holds true for other major cities as well. Pests spread bacteria and jeopardize food safety. They put guests at risk.

Now is the time to take action to prevent incursions of flies, wasps and ants before they become a problem. Environment and Climate Change Canada recommends an integrated pest management approach to controlling such pests. It’s a proactive approach that emphasizes preventative techniques like good sanitation, habitat modification, exclusion and non-chemical pest control methods that targets the sources of pest infestation, like food, drains and other potential pest shelters. Restaurant owners and managers can implement this holistic approach that identifies and addresses why pests are attracted to foodservice establishments in the first place. It’s an environmentally-conscious solution to effectively manage pests.

Check out the following integrated pest management tips to help prevent pests in outdoor dining areas:

Proper Sanitation

  • Flies and wasps are attracted to food odours and garbage, so good sanitation is key. Flies can carry more than 100 pathogens and transmit bacteria like E. coli and salmonella every time they land. Stinging pests are more a threat to your customers than food safety, and you should take precautions since reactions to stings can vary – from an infection at the site of the sting to severe allergic reactions.
  • Cover all trash cans with tightly sealed lids to prevent odours from escaping and be sure to empty trash cans regularly. Odour neutralizing agents can be used inside trash receptacles.
  • Clear customer plates as quickly as possible. Otherwise, this can serve as an open invitation for pests.
  • Wipe down tables and chairs in between customers to keep crumbs at a minimum.
  • Do a thorough sweep in between shifts and before closing.
  • Clean up spills immediately, even if it’s just water. Ants and cockroaches look for crumbs left behind by diners and spills not properly cleaned.

Exclusion and Maintenance

  • Eliminate sources of stagnant water, which can attract mosquitoes, midges, crane flies and fungus gnats.
  • Clean gutters to avoid rainwater build up.
  • Use less lighting if possible and replace fluorescent lights with sodium vapour bulbs. At night when the lights come on, flies are less attracted to sodium vapour lights, cutting down on flying action around the patio.
  • Keep doors closed when not in use, and install door sweeps and weather stripping around all entrances to eliminate potential entry points – and to keep pests from migrating to inside your restaurant. Ants, for example, aren’t picky when it comes to finding a meal, but are especially attracted to the grease that can be found in restaurant kitchens.
  • Work with your pest management professional to install insect light traps or baited traps as needed to help control flies and wasps.

Landscaping and Decor

  • When making landscaping decisions, be aware that flower beds, mulch, shrubs, bushes and trees all lead to an increased risk of spiders, ground beetles, centipedes and even rodents.
  • Avoid planting brightly coloured or fragrant flowers and fruity or bushy shrubs.
  • Keep bushes and other branches cut away from your patio.
  • Work with a pest management professional to assess any decorative water features and determine the need for additions such as mosquito-eating fish to eliminate mosquito larvae. Make sure the water is changed and circulated as mosquitoes can breed in just an inch of standing water and are known to lay their eggs there.
  • Choose umbrellas, awnings or outdoor décor with dark or neutral colors to further discourage stinging pests.
  • Avoid overwatering plants and allow soil to dry in between watering. Otherwise, overly-wet potted soil, flower beds and mulch can provide habourage for crawling pests and breeding spots for gnats and midges.

The tips above will help fend off flies and other patio pests from becoming regulars at your restaurant. By working with your pest management professional to implement your own integrated pest management plan, you’ll be able to make your patio an oasis for guests — not pests — this summer.

Alice Sinia, Ph.D. is quality assurance manager of regulatory/lab Services for Orkin Canada focusing on government regulations pertaining to the pest control industry. With more than 20 years of experience, she manages the quality assurance laboratory for Orkin Canada and performs analytical entomology as well as provides technical support in pest/insect identification to branch offices and clients. For more information, email Alice Sinia at or visit

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