February Pest of the Month DRAIN FLIES

There are many species of "drain flies" in San Antonio, but they all have very similar life cycles and characteristics. Drain flies get their name from the fact that they are found in and around drains. These tiny insects do not enter the house from the drain, but they breed in the drain.

The slime and organic matter that builds up in the drain is a prime site for drain flies to lay their eggs. The larvae that hatch feed on the sludge and eventually emerge as adult flies. The average lifecycle of a typical drain fly is 2 weeks, so their numbers increase rapidly.

To reduce drain flies, you must eliminate their food source and breeding sites. You can stuff your disposal with ice cubes and run the disposal to help break up the organic matter in the drain. But you should also take a steel brush or a brush with strong bristles and clean out the drain as best you can. This should be repeated every 3-5 days until the flies are eliminated.

Drain cleaners (such as Drano®) will help, but for the best results, purchase products similar to RID-X. These products contain bacteria that naturally break down the organic matter coating the drain.

Restaurants often have drain flies breeding in unclean mops and brooms. Check those items in your home and remove them as needed. To eliminate food sources for drain flies, place food left on the counter in tightly sealed containers or in the refrigerator.

The best control for drain flies is a combination of eliminating breeding sites and adult food sources.

For more information contact IPM Program Specialist and Entomologist, Molly Keck at 210-467-6575 or email at mekeck@ag.tamu.edu