Narrow Banded Pond Fly and rat-tailed maggots

Sericomyia militaris - The narrow banded pond fly - its larvae are rat-tailed maggots

Well, I learned something new today.  I have known about a fly larva called a rat-tailed maggot and I knew about hover flies, but I did not know that rat-tailed maggots were the larvae of hover flies, also called flower flies.  Now, not all flower flies have this kind of larvae, but those that belong to the group of syphids (family Syphidae) in the tribe Eristalini do.  If you want to see a photo of a rat-tailed maggot, click here.

The interesting thing about rat-tailed maggots is that they can thrive in polluted water.  And we're not talking about mildly polluted water, but heavily polluted, stinks to high heaven, filthy, disgusting water.  That's because they don't get their oxygen from the water, but rather from their "rat tail," which is a breathing tube that extends above the waterline.   The water itself, which can actually be more of a mire, contains organics that the maggots feed on.

Furthermore, the larvae don't stay there long.  As is common with most maggots, the time they spend in the larva stage is relatively short, often only as long as two weeks.  After this, they pupate.  The larvae crawl out of their watery habitat and find a relatively dry, protected area to undergo their final moult.  They spend another few weeks (depending on the weather) in this state before emerging as adults.

Flower flies are remarkably beneficial insects.  In their adult stage, they are important pollinators and part of the food web.  In their aquatic stage, they convert organic wastes into usable biomatter and are preyed upon by numerous aquatic organisms.  So, the next time you see a fly that looks bee-like, show it a little love.

Thanks for reading.

Eric Svendsen     www.ericspix.com