Tag Archives: classification

Oak leaf-rolling weevil (Homoeolabus analis)

If you’ve been to Florida and stared at any of the live oaks there, you’ve probably noticed the tiny, burrito-shaped structures on many of these leaves. If you haven’t seen them, you might have heard them — they accumulate under oak trees in sufficient numbers that you’ll hear crunching as you walk over them.

These structures are made by the oak leaf-rolling weevils in the subfamily Attelabinae (the “leaf rolling weevils”, appropriately) and they are called nidi (Latin for “nest” or “place where egg is placed”). Several species nidify (yes, it’s a verb) oak but perhaps the most common species is Homoeolabus analis. I caught a female in the act:

Zolfo Springs, FL.

This shows her fairly well along in the process but I really wish I could show you a video of her technique, which is amazing. Before this stage she’ll first survey the leaf compulsively, scissor the leaf in half at the midrib, then use mandibles and legs to feverishly roll it into a burrito. Midway through the nidification she’ll deposit an egg (sometimes two) and then, I gather, will guard the nidus from parasitic wasps while it hardens up a bit. She’s also guarding against intrusion by the the thief weevil (Pterocolus ovatus), a blueberry-like attelabid that sneaks into fresh nidi and eats the eggs. But that’s not all. Female thief weevils will leave their own egg inside the nidus and this theft of home is the source of their common name.

Here’s a male, by the way (you can tell because he has a longer neck):

On that note, here’s an egg I found inside one of the nidi. I think it’s Homoeolabus analis but it could be Pterocolus ovatus.

I opened up several dozen of these nidi and found all sorts of drama. Several had some sort of orange cecidomyiid larvae (more pics) in the middle layers of the nidi:

And found plenty of eggs that were definitely not weevil eggs but that are not photogenic enough to post. Suffice it to say that there are many parasitic wasps that have been known to attack this species. If I lived in Florida I’d have hundreds of these in vials just so I could watch the emergers. Better than television.

As a side note, if you have a beetle that looks like Homoeolabus analis, it easily could be Synolabus nigripes, a member of the Attelabinae that also has red, punctate elytra and pronotum; black legs with swollen femora; and long rostrum that is largely though variably black. And ranges overlap (see maps here and here). Below are some ways to tell them apart that I collected from a variety of sources. Many involve knowing which sex an individual is, but luckily males have longer necks. And if an individual is caught nidifying a leaf, it’s a female.

Homoeolabus analis

  • sides of neck parallel, not wider near pronotum (from Boris Büche)
  • males: distance between pronotum and eyes equal to length of rostrum (example)
  • males: pair of spines/projections on the submentum (p. 175 in The Insects and Arachnids of Canada; p. 707 in American Beetles); need a microscope
  • females: straight tibiae (see 2nd pic near top of this post)
  • on, eating, or nidifying Quercus spp.
  • black parts have a blue tinge (see above pic) (LeConte 1876, page 10); this characteristic seems ignored in all later descriptions … but I think it should be featured

Synolabus nigripes

  • width of neck behind eyes greater than width at tip of neck (from Boris Büche)
  • males: distance between pronotum and eyes less than length of rostrum (to me, they evoke the Spy vs Spy comic book characters from Mad Magazine)
  • males: large spine(s) on front femora (example)
  • females: “ventral rostral apex in lateral view with median conical prominence” (American Beetles, p. 707); need a microscope
  • on, eating, or nidifying Rhus spp.; usually sumac, sometimes poison ivy
  • no bluish tinge on black parts (Evans p. 464)

If you still need help IDing, submit a photograph to either iNaturalist (I’m @colinpurrington if you want to tag me in your observation) or BugGuide. Here are Homoeolabus analis observations on iNaturalist.

If you want more information on Homoeolabus analis or the parasites that attack it, here’s a great overview by Donald W. Hall and Lyle J. Buss (both at the University of Florida). And here’s a post by Charley Eiseman with pics and natural history of yet another (but not all-red) oak leaf-rolling weevil, Attelabus bipustulatus. If you want to see some nidifying, there are YouTube videos of various Attelabidae.

Etymology of garter snake

Even though “garter snake” has been the common name for Thamnophis sirtalis for over 200 years, I discovered this week that people who know a lot about garter snakes don’t agree on why. There are two theories: (1) the snakes were named after stocking garters and (2) sirtalis is the Latin word for stocking garters and thus the common name was derived from the Latin binomial. I know, not a burning question for most, but I was curious given that snake fans seem to choose one or the other without further mentioning why. So I looked into it.

Garter holding up a woman's stocking (from The Practical Costumer)
Photograph of an embroidered garter. Image from the The Pragmatic Costumer (click image to read her article).

(1) Most articles, books, and websites explaining the common name suggest it’s because the snakes resemble garters, pieces of fabric that were fastened right below one’s knee (the garet, in Celtic) to keep stockings from falling down (that used to be a huge problem). The resemblance is lost on most people today, especially guys who don’t know their lingerie history, because garters are now frilly and made of silk or satin and thus not at all snake-like. But back in early Europe they often had lines and patterns that could easily remind somebody of the stripes and scales of a snake. And everyone wore them: women, men, even kings, so they were ubiquitous, visible, and probably conversation starters. So it’s not surprising that somebody eventually referred to a particular type of snake as a “garter” snake. 

In etymology it’s important to establish when a particular word first appears, so I consulted the Online Etymology Dictionary and learned that garter snake first shows up in 1775, in the United States. The Online Etymology Dictionary says the name is related to stocking garter but doesn’t provide proof of this or any links. Curious, I found that “garter snake” shows up even earlier, in 1773, in a description of specimens in somebody’s collection in Lichfield, England. Again, there is no explanation of why the common name was garter. I’m sure the first usage of “garter snake” goes back even further, too, if you had access to a good database of letters and newspaper articles from the time. I don’t.

(2) A potentially related hypothesis for the common name is that sirtalis means “like a garter”. This is exactly the claim thousands of scientists and naturalists make. If true, then the common name might have been launched when Linnaeus published his classification in 1758. Alternatively, maybe it just confirms that he knew of the common name and simply applied the Latin cognate for the species. But I was suspicious of this claim because when Latin was a living language there weren’t stockings or the need for garters. Sure enough, when you look up sirtalis in a Latin dictionary, it’s not there. Like many of words Linnaeus used in his binomials, he made it up by combining Latin and Greek roots, leaving us to guess at what the new word might mean. Kraig Adler theorizes that the word might be a combination of siro (Greek for cord, rope, or string) and talis (Latin for such, the like), and thus might mean “ropelike”. So when people claim that sirtalis means “like a garter”, they are incorrect. The first appearance of the “like a garter” claim seems to in 1976, in Robert Parker Hodge’s Amphibians and reptiles in Alaska, the Yukon, and Northwest Territories. I don’t own the book so I’m not sure if he cites somebody, in turn.

Although sirtalis does not mean “like a garter”, I guess it’s possible that Linnaeus had garters in mind when he concocted a rope-like species name for the snake. He probably wore garters, and perhaps called these snakes “garter snakes” before he officially named them. The question, then, is whether the common name predates his scientific name. In looking into this I discovered a second common name that I think was borrowed from German or Dutch: kouse band. The French use serpent jarretier (jarretier means garter), and Swedes use strumpebandssnok. Anyway, it seems that everyone in 1790s Europe, regardless of language, called them snakes-that-look-like-garters. Would be nice to know which language first started to call them by the respective name, but to do that I think I’d need something other than Google’s English-based book search. Note that the 1773 date I mentioned above was found with Google, and thus is probably simply related to my usage of the English-language version. There are likely other databases out there without such language problems.

A deservedly rare explanation for how the garter snake got its name is that it is a misspelling of guarder snake, garden snake, gardener snake, or garten snake. Some of these variants are quite common on the internet, and I think most people can blame their parents.