Answer to the Monday Limerick: Horntail

Tremex columba (Urbana, Illinois).

As many of you surmised, yesterday’s limerick referred to Siricid sawflies, also known as horntails. These insects are wasp-like in appearance, partly because they belong to the same order as wasps, Hymenoptera, and partly because the coloration of some species has converged on wasp-like stripes.

Horntails belong to an older radiation, though, one that never developed the characteristic wasp waist nor the typical wasp carnivory. Horntail larvae feed on dead wood, and the fierce appearance of the adults belies a gentle disposition. The long “tail” cannot sting, being merely an egg-laying structure.

Tremex columba – the pigeon horntail (Urbana, Illinois).

Points are awarded as follows: 5 to Chris Murrow for being the first to pick the suborder, and 5 each to Josh King and Jesse Hardin for being roughly tied here and on FB for guessing Siricidae.


7 thoughts on “Answer to the Monday Limerick: Horntail”

  1. Amazing how a white box can make even a tattered-winged critter look amazing. Love the blue (sky?) background.

    By coincidence, I found some photos of this same species in my archives and was thinking to do a post. Not nearly as good as these, although it is in the act of ovipositing – think I’ll wait a bit now 🙂

  2. I’ve been working on the invasive sirex noctilio, and at least for the sirex species the consensus is that they feed on the fungus (and wood) thats concurrently deposited during oviposition with the egg and mucus. The cooler part of the siricid story are the nematodes associated with them…the females also deposit the nematodes when ovipositing, and the nemas also feed on the fungus deposited by the siricid. The nematodes have two forms, a fungus feeding form and then a parasitic form. They change into the parasitic form when they get close to a siricid larva, penetrate the larva and make their way to the ovaries around pupation. And then it starts all over again 😉

      1. Sterilizes the females. Doesn’t sterilize the males, but it’s a dead end for the nematodes bc they don’t make it back into the wood from parasitizing the males. Check out some of Robin Bedding’s papers if your interest is peaked 🙂 it’s a pretty neat system for an insect that leads a relatively boring adult life (don’t feed, don’t need to mate with a male)…all the real fun happens inside the trees.

  3. How interesting that there are hymenopterans w/out the cinched in waist. Apparently they opted for athletic vs. dainty builds. Good for them. =)

    I don’t suppose if one’s not an entomologist (or brainy, disciplined amateur) there’s any handy, dandy way to figure out if a bug is safe to handle? Speaking of pain-wielding or benign ovipositors. Particularly among those inverts. with visible legs, mandibles, pokey behinds, etc.? Guess it’d be hard to know whether a pokey tube had aggressive chemicals in it or not just by eyeballing it…

    Really enjoyed the exchange w/Kez, too. COOL stuff!!! (p.s. just realized Kez made a pun, intentionally or otherwise–a relatively boring adult life?? An animal that drills holes into and lives within trees? =))

  4. >> “Horntails belong to an older radiation, though, one that never developed the characteristic wasp waist nor the typical wasp carnivory ” [ even if their taxon placement is problematic ].

    Probably not a good idea to make categorical statements about insects like above considering how rapidly evolutionary adaptations develop in insects (25 generations or so).

    Consider the diet of the family Orussidae (parasitoids), the ‘wasp-waists’ of some fossils attributed to the Symphyta, the many members of the Apocrita with nectar/pollen diets (bees) which are hardly carnivores but could be called reasonably typical. Considering my ignorance about the full range of Apocrita morphology, it would not surprize me if there were not a large number of groups within that also lacked the “wasp-waist” configuration.

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