An Appreciation Of The Cluster Fly

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(Host)  Spring peepers, songbirds and babbling brooks: these are some of the sounds of spring. 

But there’s another one that may not be so welcome:  the buzzing of the pollenia rudis – better known as the cluster fly. 

VPR’s Steve Zind has this…appreciation.

(Zind) For such a hapless-seeming insect, the slow moving cluster fly can really be annoying. 

Just one of them dive bombing a lampshade is bad enough, but when they gather in rock festival numbers in a sunny window in the kitchen you want to pick up the phone and holler for help.

(Turmel) "We get a lot of calls on cluster flies."

(Zind) More often than not that someone is Jon Turmel, the state entomologist – probably the only person around who finds something to love about cluster flies.

"Oh absolutely.  Keeps me employed!"

(Zind) That might be a bit of an exaggeration, but over the years, Turmel has collected some fascinating cluster fly stories. 

(Turmel) "I had a friend that said that he had the president of a local university at his house and had a cluster fly fall in his wine at dinner and he was totally embarrassed." 

(Zind) And Turmel knows some great cluster fly trivia.  For example, if you’ve never investigated what a dead cluster fly smells like, we can save you the trouble. 

(Turmel) "When you crush them, or hit them with a flyswatter, they have buckwheat honey smell.  Most flies don’t have that."

(music ‘Never Swat A Fly") 

(Zind) Before you break out the flyswatter or vacuum them into oblivion, think about this:  Mr. and Mrs. Cluster Fly are pretty harmless- as flies go.

(Turmel) "The cluster fly does not breed in the house.  It does not feed in the house.  It doesn’t spread diseases.  They’re freeloaders." 

(Zind) Because basically they’re in your house just to hibernate.  And after spending the winter in your nice cozy walls or attic, the cluster fly wants nothing more than to get outside.  But a poor sense of direction means a lot of them take a wrong turn and end up inside, with you. 

The ones that do make it outdoors spend the summer laying eggs in the soil and playing the bad guys in a story line that resembles invasion of the body snatchers. 

(Turmel)  "The eggs hatch and become little maggots that then bore into earthworms. There they spend the maggot stage feeding inside of that earthworm where it will eventually kill it.  It’ll then come out of the earthworm, pupate, then crawl out as an adult and start it all over again."

(Zind) This process repeats itself four or five times in the course of the summer.  So the cluster fly that squeezes into a tiny opening on the outside of your house in the fall to spend the winter inside might be the great, great grandchild of the one that was banging against your window in the spring until you let it outside. 

Turmel says cluster flies are found all over the country, but there’s some evidence the Northeast has a greater number.  Which brings to mind another story – about the time he found a layer of dead cluster flies inches thick in someone’s attic.

(Turmel) "And we literally had to shovel them out of the attic.  In fact some houses we found if we took the cluster flies out we wouldn’t have any insulation." 

(Zind) That’s not the kind of thing that’s going to endear them to anyone, but maybe you’ll see those cluster flies buzzing in your sunny window a little more sympathetically if you consider this.

(Turmel) "They’re just so happy that its spring.  Just like we are!" 

(music up:  "Fly Trouble")

For VPR news, I’m Steve Zind. 

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