My Twitter feed alerted me to a new interaction – I’d been flagged in a tweet by @MarconiRebus containing a most intriguing photo:

An earlier tweet provided a little more info:

Whoa. That is one weird bug!
Aquatic insects do have a tendency to look weird and wriggly, but this long-tailed beastie was nothing I was familiar with; also, the photo was coming from overseas, making this ID challenge potentially tricky.
Luckily, that snorkel-butt was an incredibly useful character for narrowing the ID down to one insect Family. There are a number of aquatic insects that use a similar apparatus for breathing, but none that I’m aware of that look quite so wormy. A search turned up a most awesomely-named fly larva:
“Rat-tailed Maggot”
You gotta love that name; it conjures up so much “EW”! π
The Rat-tailed Maggot is the larva of a drone fly (Eristalis sp., Syrphidae).Β Syrphids are generally known as “hover flies” for their ability to fly in place. The adults tend to hang out near or on flowers, and many mimic bees.
I actually encountered some large bee-mimicking hover flies (possibly drone flies, but difficult to tell from my photos) while camping last week; this isn’t the most awesome photo ever, but it gives you the general idea of the nature of the beast:
See Miles’ comment about this photo, below – I made a boo-boo! Thanks, Miles!

There were ample ponds and quiet pools in the area, which would have made perfect breeding grounds for these fascinating flies!
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The flying insect looks more like a tabanid?
Miles, I never would have placed this as a Tabanid, but I see now that you’re right! I didn’t know about this hovering behaviour of the males! I’ll note the error in my post π
Heh no problem, I only knew this because I’ve made the same mistake before. π
π
Also, awesome flight shot! That’s not an easy photo to get, and yours is fantastic!
For once in my life, I actually knew what the mystery critter was!
Awesome! π
Well, at least these large tabanids sound like bees and it is likely the larvae live in ponds or their edges. I’ve had a Hybomitra emerge from the backyard pond (right into the killing jar, nasty buggers). I can still remember (with significant envy) Tom Eisner’s Science cover photo of a tabanid larva eating a frog from underneath. Great, if annoying, animals. Matthias Buck was just telling me about the habit males have of hovering in convenient localities and waiting for females. I wonder if he reads your blog?
I have to find a copy of that photo by Tom…I’ve definitely never seen it before! Also, I doubt that Matthias reads my blog, or he probably would have corrected me on my mistake just as quickly as Miles did π