Monday, March 12, 2012

They are Dragonflies, not Dragon Flies

Once in a while I’ll see someone refer to “dragon flies” or a “dragon fly” which causes a brief piercing sensation in my head. Just kidding—it’s more of an open-handed thump to the back of the skull. Just kidding again! It really isn’t a big deal, but I thought I would explain the protocol regarding whether the fly part of the name is separate or not.

Maybe referring to this as protocol is a bit strong, since it really seems to be more of an unwritten guideline as far as I can tell, but I’m happy to be corrected if I’m wrong about that. So here’s the guideline: the fly part of the name is a separate word for insects in the order Diptera—the two-winged insects which are also known as true flies. For insects in other orders which include fly in their name, it is not a separate word (dragonfly, for example).

From Wikimedia Commons
The Diptera include house flies, crane flies, robber flies, march flies, deer flies, horse flies, black flies, fruit flies, blow flies, bot flies, and lots of other flies including some that we don’t even call flies like mosquitoes, gnats, and midges (it’s a very diverse order of insects). In each of these cases which include fly in the name, it is a separate word.

There are many non-Diptera insects that include fly in the name, but these are not true flies, so fly is not a separate word. These include dragonflies and damselflies (of course!), as well as mayflies, caddisflies, stoneflies, butterflies, snakeflies, scorpionflies, alderflies, dobsonflies, and sawflies. No doubt there are many other examples which don’t leap to mind at the moment.

This concept extends to other cases. Ladybugs are not true bugs in the order Hemiptera, so bug in that case is not a separate word. Of course, there are those who say that ladybug shouldn’t be used at all because of the fact that they are not true bugs, but it rolls off the tongue so much more easily than ladybird beetle and it saves two syllables. Insects in the order Hemiptera are true bugs, so they are lace bugs, stink bugs, ambush bugs, leaf-footed bugs, boxelder bugs, et cetera.

From Wikimedia Commons
Even outside the world of arthropods we have the starfish—not a fish, so fish is not a separate word. Maybe sea star is a better name than starfish, but starfish has a quality that seems to appeal to the general public much the way ladybug does, so it may never go away. On the other hand, there are the sea cucumbers which, of course, are not true cucumbers or even a vegetable of any kind—they are animals in the same phylum as starfish...  ...I mean, sea stars. So there’s a case where this guideline doesn’t seem to apply.

Anyway, now you know the fly guideline. Remember, if you want to save me from that painful mental jab, use dragonfly and damselfly, not dragon fly and damsel fly, and we’ll all get along just fine.

6 comments:

  1. The Syrphid-studiers throw a spanner in the works though, as they refer to their organisms as 'hoverflies', without the space.

    As for the Coccinellidae, my understanding was that 'ladybird beetle' is basically an artificial construct to get around the fact that we call them ladybirds, and you call them ladybugs

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    1. I never did trust Syrphid-studiers. :-) All the more reason to consider these guidelines rather than rules!

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  2. Ha! I, too, have had issues with this and blogged about it 2 years ago: http://natureid.blogspot.com/2010/02/bat-star-patiria-miniata-its-always-fun.html. I had a medical entomology professor who was just as anal about proper grammar and common names as he was about Leishmaniasis. The bugger is when Hemiptera and Homoptera got reclassified under Hemiptera with a split to suborders Heteroptera and Homoptera: http://natureid.blogspot.com/2010/08/seed-bug-lygaeidae-family-i-thought.html. So, is it now mealybug or mealy bug?

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    1. I don't think anything should be called "mealy", so I don't like either name!

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  3. I see "stinkbug" more often than "stink bug", which really stinks.

    There is no suborder Homoptera, as the group was demonstrated to be paraphyletic - i.e., parts of it are more closely related to the Heteroptera than they are to other former Homoptera. The order Hemiptera now includes several suborders - some formerly placed in the separate order Homoptera.

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    1. Oh, Ted, I can't keep up with all these changes - 3 to 5 suborders now? Several university websites and online dictionaries haven't updated the suborder Homoptera, either. Um, thanks, once again, for correcting me.

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