• Chelle Hartzer

This isn't the Deathly Hallows (AKA: Everyone's on a deadline)

Too soon?

I had a death in the extended family recently. It’s always hard to lose someone and be with others who are grieving too. However, it also brings up some interesting pest information.

This week, I’m going to talk about coffin flies. Yep, just like they sound! These are often called phorid flies, humpbacked flies, and scuttle flies. I think they should also get the name “death eaters”! This is an entire family (Phoridae) of small flies and most can be found developing on dead and decaying organic material. In North America, there are over 375 species. They get the name “humpbacked” because of the humpback appearance and “scuttle” comes from the distinct way they run instead of flying most times. No matter what you call them, they are a small fly that is often misidentified as fruit flies, fungus gnats, and other tiny flies.

Phorid fly

It may sound a bit morbid, talking about death and flies, but in pest control, this is pretty important. In residential settings, small animals may die in crawlspaces, wall voids, attics, etc. When these flies show up, they can be traced back (hopefully) to the source and that carcass can be removed. This can occur in commercial facilities as well, particularly older structures that may not be sealed well. Since females can lay about 750 eggs in their short lifespan, it doesn’t take long for populations to increase and for people to notice them.

If small flies feasting on the recently dead isn’t really your thing, the other place scuttle flies are often found is in sewage. Just like decomposing carrion, sewage is wet, decaying organic material. If these are found inside structures, the likely breeding ground is probably a broken pipe. Under perfect conditions, these can develop from egg to adult in as little as fourteen days. If a pipe is leaking in the soil under a structure, it doesn’t take long for these to reach infestation levels. Also, they manage to squeeze through the tiniest cracks. When the larvae are almost ready to pupate, they start to crawl upwards, towards drier ground. The soft little body squishes itself through minuscule cracks in the floor and then the adults are seen. Along with sewage breaks, humpbacked flies are found around water treatment plants. Makes sense with the “dirty” water coming in to be cleaned.

Since we are talking about death, we have to talk about coffin flies and …well…coffins! Coffins that are buried typically don’t have many insect issues, they are far enough underground and sealed fairly well. Plus, in cemeteries, there is plenty of open air, even when coffin flies get to a body, when they come out, there is plenty of room for them to disperse. Mausoleums, on the other hand, provide excellent habitat and food resources for coffin flies. These are enclosed and the flies have a more difficult time getting out, so they are much more obvious flying around in the confined space. Obviously, this can be distressing to those mourning loved ones.

One other interesting place phorid flies are a major pest issue is mushroom farms. Like mausoleums, these are enclosed (though much larger!) and have plenty of decaying organic material that mushrooms need to grow. Since the substrate needs to be kept damp and has that rich decaying material the mushrooms need, it is a perfect breeding ground for the phorids. Fun fact: in Pennsylvania, the phorid flies at mushroom farms get so bad, surrounding residential areas have major issues with them!

Because of what phorid flies are feeding on and breeding in, there is the risk of them spreading diseases. Think of how much bacteria and other pathogens are on carrion and sewage. It’s especially important to manage these flies in sensitive accounts like hospitals, restaurants, and food processing sites among many others.

Death is fascinating (though depressing, I admit) when you consider how insects and natural conditions can break down a body and return those nutrients to the soil. If you have a scuttle/humpback/coffin/phorid fly issues and feel you’ve hit a dead end, don’t be a deadbeat, contact me to see how I can help!

Lagniappe – this is some of the absolute COOLEST research going on! (of course I am biased though!)

And I can't resist: not all phorids eat the dead, some eat the living!!!

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