Saturday, March 13, 2010

What if and What is it? Mystery Beetles of the Moose Pasture

Gray and chilly this morning in Edmonton, only a week until the end of calendar winter. Of course, here in central Alberta, the calendar is never more than theory until May, a wistful picture over a grid of snow white blocks. Alberta Bugs has had rumours of insects in flight in Calgary, but not even a Mourning Cloak has shown up here. Still, the snow cover is in retreat, the southern exposures are becoming exposed, and one can always hope that El NiƱo will grant us an early Spring.

But Spring isn’t here and An Inordinate Fondness is all set for its second issue. Alas, I seem to have plundered most of our digital beetle collection for previous postings, leaving little new to add. But, when the facts are inconvenient, it is time to turn to theory, and the theory of the Home Bug Garden (HBG) is that I can create an oasis of biological diversity in urban Edmonton. As a test of how well I have succeeded to date, lets compare the HBG diversity to – well, the Moose Pasture. This seems appropriate since the Moose Pasture is our theoretical escape in the country, a quarter section of bush land near Elk Island National Park where we take our bugpersons’ holidays, putter around appreciating the biological diversity of central Alberta, and daydream that some day we will do more than putter. Sometimes we can even put a name on a beetle, like this wasp-mimicking long-horned beetle Clytus ruricola (Olivier) that probably uses some of our aspen or birch logs as a larva (thanks to Eric Eaton and Kenn Kaufman in the Kaufman Field Guide for the information that they breed in decaying deciduous trees).

You may recall from the When Alien meets Alien: De gustibus ... posting, the HBG claimed 339 species of animals identified from its environs including 28 beetles. Not bad for a quarter acre urban lot, but not really a strong showing for the beetles. I am happy to say this total has risen in the last month to 362 species of animals – but, alas, the beetles have failed to budge. In fact, almost all the increase has been due to moths, thanks to Feralia – the annual celebration of Lepidoptera identification, music, and the usual shenanigans hosted by John Acorn in February. In comparison, our Moose Pasture ‘boasts’ 492 identified animal species including – what, only 31 beetle species! Well, our Inordinate Fondness obviously needs some work and we don’t have a beetle equivalent to Feralia. But, we do have a beetle carnival to appeal to and perhaps its readers can shed some light on a few Moose Pasture mystery beetles.
Here’s one example (with Ted MacRae in mind), a beetle we have labeled Dicerca possibly tenebrosa (Kirby). However, we note that the Strickland Entomological Museum says “Dicerca tenebrosa is easily confused with other Dicerca species” (e.g. Dicerca crassicollis LeConte (Kirby)) and that one character for this species is “a short second segment on the antennae”. Characters like this always make me ask - How short and in comparison to what? Since both of the bupers above bore in conifers, I wonder if we aren’t on the wrong track? The Moose Pasture is full of aspen but has only a handful of spruce (I think most burned up in the early 1900s when the last large fire swept through the Beaver Hills Region), so I wonder if this may not be the Bronze Aspen Borer Dicerca callosa Casey? In case this flat headed borer is too easy, here is a mystery weevil that has no guess at all.

We would be especially pleased with an id on the weevil, but we know there are lots of them and they tend to look alike. So, how about a few of the more colourful Chrysomelidae. Below are a few guesses and one we just don’t know.

Carrying on with the colourful – a few gay beetles on a gray winter day – here’s one Scarabaeidae we think we know and one we don’t.

Well, the sun seems to be trying to peep through the clouds, the temperature is above zero, and if I don’t get outside, then I won’t have any chance to see my first Mourning Cloak, Ring-billed Gull, or other hopeful sign of Spring. One thing that I have noticed in pouring over our Moose Pasture insects is that from the few we have identified, there isn’t much overlap with the Home Bug Garden fauna, and the two sites are a mere 53 km (33 miles) apart. I think this has implications for what I am trying to achieve, but that is something I will need to think about. In the meantime, it seems most appropriate to end, not with a beetle, but with an eponymous Moose Pasture beastie. When the thaw does come, there will be lots of reminders of this animal dotting the landscape - and ones that some scarabs will no doubt find attractive.


  1. The Donacia sp., with her legs dangling over the leaf edges, looks exhausted with her burden! The different metallic hues on the pair is interesting.

    Was the moose taken with a camera trap? I hope so, as it looks a bit close to be safe!

  2. Hey nobones,

    Yes, the sexual dimorphism in the hues is interesting. Haven't been able to find out anything about it though.

    Moose was captured on a trail camera. There are at least 3 male moose that wander the Moose Pasture. Except during the rut, the females with young are probably more of a worry, but so far the moose move on when we encounter them and let us play with the bugs.



  3. Just over a week ago I returned to my office after a noon hour stroll and a ladybug was crawling on my coat - must be a good sign of spring! :)

  4. I'm also inclined to go with Dicerca callosa, based on the antennomeres 2 and 3 of equal lengths (in tenebrosa 2 is shorter than 3). Good job using host info to deduce a likely ID.

    Can't help with the weevil, but the "Zygogramma" has more of a "Chrysomela" look to it (the former are usually more convex and solid). Orange and black chryso #2 looks like Phyllobrotica, but I don't know the species well enough to be more specific.

    I agree with Trichiotinus assimilis, and your melolonthine looks like Dichelonyx - the genus is a mess.

  5. I think I'm going with Ted's id for the Dicerca (that is one of his groups of speciality), but I think the Zygogramma/Chrysomela may be Calligrapha californica corepsivora Brown.

    At least (1) that is what it keys to at:

    (2) Looks right; and (3) I collected something just like it off Nodding Beggarticks (Bidens cernua) last Fall.

  6. Yep, I agree with Calligrapha now that I look more closely. Good job!

  7. "One thing that I have noticed in pouring over our Moose Pasture insects is that from the few we have identified, there isn’t much overlap with the Home Bug Garden fauna..,"

    I'm curious what percent overlap you have found i.e. 1%? 10%? 30%? Would be interesting to compare your yard biodiversity survey with other Alberta ecosystems other than the ‘Moose Pasture’ such as the more prairie-like landscapes to see if more or less overlap.

    I guess in the end increased biodiversity in your yard is a good thing, even if unique only to your yard or urban environments (and provided harmful species not finding ideal breeding grounds of course!)

  8. Hi Middle Earth,

    That is a good question. For the beetles, ignoring a couple that I have identified only to family, only 2 of 55 species are shared in common - so, less than 4% overlap (7% if the ones with only family ids are the same species).

    Some of the differences have obvious explanations - at home we have only a small pond (just turned the bubbler on this afternoon), but the Moose Pasture is about 1/5th water (or was before the drought). So, not much in the way of water beetles here at home. Also, there are lots of moose, deer, coyote etc. at the Moose Pasture and so we have some dung beetles not found at home. The leaf beetles are pretty different too - because the plants are mostly different.

    I really need to do a more thorough survey at both sites to have much authority, but I'd be surprised if beetle similarity between the two sites reached 20%.

    In comparison, 4/14 species of Vespidae (the family that includes the yellow jackets and hornets) are shared - almost 30%. Wasps like flowers, so the Home Bug Garden has twice as many species recorded as the Moose Pasture. I guess I like flowers more than Nature does.