Regardless if you are treating a residential or commercial account for small flies, all buildings have plumbing and pipes. “We get not only food debris down in these lines, but biofilm,” said Dr. Gerry Wegner.

No matter the fly, Wegner, former technical director for Varment Guard Environmental Services, said eggs are always laid in the food source. The type of small fly depends on the location of the food source. Wegner used drains and pipelines as examples. If organic matter is on top of the drain, fruit flies are likely to be the culprit. Inside the drain, however, Wegner said PMPs will be looking at phorid flies or moth flies depending on how deep the organic matter is on the sides.

DOS AND DONT’S. Wegner said bleaching drains and pipes to get rid of flies is a misconception. “Insect eggs can tolerate bleach, particularly if the eggs and larvae are deeply embedded in the biofilm,” Wegner said. “They pour down the bleach water and it’s pretty much going to use gravity and go straight down here.”

To help eliminate the breeding source, eliminate the organic matter and biofilm that collects in and on top of the drain, Wegner said. “Solve the problem with a live biological product eating away at the residues,” he said. This may include unscrewing drains and scrubbing the sides if larvae and flies are closer to the top. Foams help eliminate fruit fly and moth fly larvae down in drain lines, however, make sure the floor has been cleaned before you apply the foam or else the treatment will be washed away. “You’re going to want to leave those bacterial cultures or enzymes working,” he said. “Time it so you’re working after the floor and most of the drainage has occurred from the mop water.”

BE THE EXPERT. In some cases, when breeding is in areas below slabs and in broken pipes, Wegner said customers will try to avoid a multi-thousand dollar bill and ask you not to open up the slab. Use your expertise and tell the client drilling holes and filling the floor with insecticides is not a long-term solution — you must break the slab.

“All sorts of nasty, decaying organic material in the fill really needs to be excavated out,” he said. “Insecticides alone may slow things down for a while, but consider you’re going to have continued leakage from the broken line, causing more water and decaying material. There will always be a number of flies that continue to lay eggs, repeating their life cycle down in there.”

MORE ACCESS. The job sometimes comes down to having enough confidence in your knowledge to take on challenging accounts that require special permissions. For example, Wegner recalled a phorid fly problem at a mausoleum that required temporarily opening a façade covering multiple casket vaults in order to access the vault with a broken seal. “You may not get very good cooperation with your client in opening up sections. There’s also certain rules and regulations honoring the rights of the family.”

Phorid flies can breed inside vaults and caskets. Wegner had to do some convincing to get mausoleum staff to access and reseal the errant vault. “When relatives come to mourn the dead, they’re not going to allow little flies skipping around.”

TAKE ADVANTAGE. Wegner said make friends with a plumber if drainage cleanouts are necessary. He or she can help unscrew the cap and give you access.

In the case of fungus gnats, Wegner said check to see if your state requires a license to deal with “plantscapes,” where fungus gnats often breed. Standing water can occur on flat roofs and fungus gnats can breed there, so get permission to access the roof if you suspect flies are present.

PACKAGE IT UP. Accounts aren’t keen on buying fly service as an add-on, so Wegner suggests building it into the service and simply charging more. “Small flies are going to be problematic and time consuming,” he said. “Too often, technicians are rushed through their day. They’re not doing a thorough enough job inspecting these accounts that deal with food and beverages.”

Pest control companies that have their own sales team should be trained side-by-side with service technicians on knowing how to sell fly control, he added. Accounts to target include those that manufacture pharmaceutical drugs and also medical facilities. “Owners and managers definitely need to be on board with selling fly control and charging more for it,” he said.