Fly control for Long Beach kitchens, drains, trash areas and restaurant back doors

The inside of a kitchen or bathroom drain is lined with a soft layer of grease, soap, hair and food that never fully washes away. Drain fly and fruit fly larvae live in that film. Pouring bleach down the drain kills a few larvae in the top inch of the pipe, but it runs past the film without breaking it up, and the flies keep coming.

Mechanical cleaning is what works. A long, stiff drain brush scrubs the film loose, and a biological or enzyme drain treatment digests what remains over several days. In commercial kitchens, floor drains under dish machines, ice machines and soda lines are some of the worst sources, along with mop sinks and floor sinks.

If the drains are clean and flies still appear near a floor drain or slab crack, a broken or separated pipe under the slab may be leaking into the soil below. Phorid flies breed in that wet, organic soil, and the fix is a plumbing repair rather than any amount of treatment.

Fruit flies need only a thin layer of fermenting sugar to breed. A single overripe tomato, the juice at the bottom of a recycling bin or a damp sponge can raise a new generation. Once the source is gone, adults die off within about a week or two.

• Refrigerate ripe produce or keep it covered during warm months
• Rinse bottles and cans before putting them in recycling
• Empty the kitchen trash daily when fruit flies are active
• Run the garbage disposal with cold water and scrub the splash guard
• Replace or wash sponges, dish rags and mop heads often
• Check potato and onion bins for a hidden soft or rotting item

Outdoor bug zappers mostly kill moths and beetles and very few biting flies, and electrocuting insects near food can scatter fragments. Indoor fly sprays knock down adults for a moment but do nothing about larvae in drains or garbage, and spraying near food prep is not appropriate in a home or a restaurant.

Indoor commercial light traps are different. They use glue boards rather than electric grids, are mounted away from food prep areas and catch flies without scattering them. They work best as a monitor and a backup to sanitation, showing whether a problem is building and which part of the building it comes from. Fly baits placed in trash enclosures and outdoor areas reduce house flies where they gather, without being applied near food.

Fly problems climb in Long Beach from late spring through early fall, when warm days speed up breeding and doors stay open to the ocean breeze. Older courtyard apartments in Rose Park, Alamitos Beach and Belmont Shore have original cast iron drain lines and shared trash areas in alleys, both reliable fly sources. In the 1920s bungalows of Wrigley and Belmont Heights, old drains under kitchen and bathroom floors can crack and leak into the crawlspace, which draws phorid flies.

Restaurants and bars along Pine Avenue, Second Street, Fourth Street and the East Village Arts District deal with flies at back doors, grease traps and dumpster enclosures shared with neighbors. Homes with backyard chickens, compost or dog runs in Bixby Knolls, Los Cerritos and North Long Beach see more house flies in summer. A dead roof rat in an attic, common after rodent work or a neglected trap, is a frequent cause of sudden blow fly outbreaks in homes across the city.