I hope you all had a wonderful Thanksgiving!
Bed Bugs were discussed at-length around the turkey here in Central New York. In a few weeks, I will post December’s newsletter article: how to prevent bringing bed bugs home from the holidays!
Perhaps the grateful group should have discussed a more pressing threat to those with leftovers from a family feast: Fruit Flies. I hear many small flies referred to as fruit flies…because a few types of flies will buzz around rotting fruit. Technically, the common name for today’s star is the Vinegar Fly.
Prevention is the best type of management, so if you haven’t done so already: consume, contain, or compost all that filled your cornucopia. I realize most residents don’t compost, but the alliteration was hard to resist…and chuck seems so wasteful.
If residents report “fruit flies” here’s what you do…
1. Inspect and identify
The adults are tiny (1/8”), but are easy to spot because they like to sit on the fruits and veggies they deem suitable for a nursery. When disturbed they will fly, but they prefer to be grounded. A noticeable characteristic of many adult Vinegar Flies is their red eyes. This isn’t set in stone though, they may have black eyes. During your inspection, make note of where there are a lot of them, this is your best clue for solving this pest problem.
Further investigation can lead to their source: some rotting fruit or veggies, the accumulated sludge that sticks to the bottom of the garbage can, bottles and cans that didn’t get rinsed, a mop that didn’t dry out, the "gelatinous scum" that builds up inside of drains, and the drain pan under a refrigerator. There should be lots of adults near the source, but more importantly: maggots! A maggot is a fly larva and its purpose in life is to eat goo, pupate (like a caterpillar going into a cocoon) and emerge as an adult Vinegar Fly. You may see the pupae (little horned packages) stuck near the goo where the maggots are doing their thing.
2. Determine if action is necessary
If you’ve found Vinegar Flies, you’ve probably found their source too—if not, keep looking. If you find a good breeding site where they’re flying around, action is necessary. Vinegar Flies do not bite humans but most people don’t want to live with them around. And as so many pests do, they indicate an underlying problem—rotting is not sanitary.
3. Plan treatment and take action
Cultural control: Vinegar Fly control is almost all about cultural control—cleaning! Sometimes finding and throwing out one piece of fruit will solve the problem. Focus efforts around where you find the flies, but while you’re at it, clean up all potential breeding sites too. If you think the source is the sink drain or trash compactor, check out the recommendations I gave in this section of my post on Drain Flies.
Mechanical control: The infestation won’t be stopped until you take away the spots where the flies are laying their eggs, but while you’re playing detective and maid, a trap can be constructed to capture adult flies. Create a paper funnel by rolling a piece of paper and securing it with a piece of tape. Place the funnel into a jar that contains a small amount of apple cider vinegar or red wine in the bottom. Instructables has a how-to on this process (but skip the hot glue gun & go for tape instead).
(Thanks to TX entomologist Wizzie Brown for this advice. Check out her blog at: http://urban-ipm.blogspot.com/2010/11/fruit-flies.html)
Biological Control: Finally a household pest for which we have biological control! If the source is hard to reach (drains, deep in cracks or crevices, etc.) Use a foam enzyme cleaner or microbe product that rapidly biodegrades the organic matter in the drain. These cleaners contain the stuff in nature that breaks down organic matter—the application just helps along the process. If you don’t know how to get a good cleaner for Vinegar Fly control, ask your PMP. Note that using harsh chemicals like bleach or a drain unclogger will make these natural cleaners not work. As always, follow the label!
Chemical Control: Pesticides aren’t usually needed for Vinegar Fly control and do not get at the underlying source. If your PMP recommends pesticides for Vinegar Flies, question him on whether non-toxic alternatives would be better both in terms of exposure to pesticide and sustainable control.
4. Evaluate effectiveness
If residents are still reporting these pests, keep cleaning daily. If the flies are gone, keep cleaning on a regular schedule and store food items so that pests can't get to them. Sanitation is the foundation of structural pest control.
Thanks to John Gideon of General Pest Control Co. in OH for his insights. I also got some information from the factsheet produced by the University of Kentucky.