Sunday, May 23, 2010

Rain, Snow & Arachnophobia: An Ode to Spiders in the HBG

As I expected, yet another cold front has hit Edmonton. Below normal and wet is dragging through its 6th day and making a muddy mess of the May Long Weekend – traditional time to plant-out one’s annuals & veggies here on the northern edge of Zone 3. Oh well, the basement spiders don’t seem to mind the snow mixed with rain. The wet grey does tend to bring out the green and certainly has been good for all the plants I’ve already impatiently planted-out. No frost yet and we wish Itztlacoliuhqui full speed south (from the predictions, though, tomorrow morning is iffy). I’ve dead-headed the spent tulips and daffodils, but it is too muddy and cold to do more. Perhaps I should be doing responsible things like Spring cleaning, and then there is that mountain of unfinished work, but instead I’ve been irresponsibly indulging myself in the bug blogs.
Best discovery so far, thanks to an old 2008 post by Chris Taylor at Catalogue of Organisms has been Attercopus fimbriunguis - a Devonian fossil on the way to (or perhaps just in) the spiders. Problematic characters include a whip-tail, no distinct spinnerets (but fossil silk), and no poison glands (although modern segmented spiders apparently never had poison glands and at least one more modern family, Uloboridae, does without them). According to the Wikipedia article (at least at this moment) the generic name is from the Old English attorcoppa for "poison-head", clearly a misnomer in this case.

Fear of “poison-heads” is called arachnophobia – and it is true that most modern spiders produce venom. Few, however, have venoms that we need to be afraid of, which makes the apparently widespread fear of spiders amongst bug bloggers even more interesting. Today’s surprise confession was from the Dragonfly Woman, but it reminded me that arachnophobia runs the bug blog gamut from the bug-photography god-like heights of myrmecos to rock-bottom-up The Geek in Question. “Very interesting” (as former colleague and mammal-tooth-fancier Gordon Sanson might put it).
The Dragonfly Woman’s story comes from her teenage years and a fishing spider in her pool. So, perfect chance for me to drag up our own cherished male Dolomedes triton hanging out around our year old pond. Alas, I fear the male found no fair female and had to bugger off to an uncertain future (probably a more common fate for wandering male spiders than being eaten by their objects of desire). My wife and I, however, were delighted that he stopped by and only wish that more and bigger spiders would take up residence. Yes, we have no Arachnophobia (but are considering buying a dvd of the movie – which features an impressive cast of mostly Australian spiders, a moderately entertaining [if factually confused] script, and good, campy acting).
So, before I get serious about not enjoying my wet weeked and get out my kneepads and start cleaning out the lower kitchen cabinets, let me showcase a few of the interesting spiders that have been lurking around the Home Bug Garden. This is Alberta, so usually the only big scary spiders occur in the Autumn (especially the Jewel Spider) or in the basement (and those introduced buggers, Tegenaria domestica, and perhaps a hobo or two, do get big, hairy, and disconcerting - although the cats like them). Also, smaller spiders seem more likely to ignore a big black camera being poked at them, and so, are more photogenic.
Actually Araneus trifolium - gemmoides has two humps on its abdomen
The discerning viewer will note that all of the pictures are credited to my wife. That’s because she has the great Nikon and macro lens, not because I tend to stand a metre behind her saying “go on, get closer, it won’t bite”. Also, many are wandering males – again, “very interesting”, but in this case, I think, not unexpected. Movement and moving on to digital immortality are not unconnected.

Actually a theridiid - probably Crustulina sticta 

Tetragnatha is the correct spelling

Phylonetta impressa (formerly Theridion impressum)

Sunday, May 16, 2010

May, Means & Extremes: Bowing to the Frost Gods

I knew it wasn’t good when I saw a flock of sandhill cranes flying south on the evening of 3 May, but April had been anything but a cruel month, so I wasn’t really expecting the blizzard of 4 May. Edmonton’s last frost is expected around 6 May, well, except for that alleged 10% chance of a later one. But then that is the downtown airport predicting and well surrounded by tarmac, buildings, and residual heat. The HBG has had last spring frosts on or before May 6th, but in only 3 of the 8 years for which I have records. There is a difference between frost and blizzard, though, and on 4 May we had the latter with about 20 cm of snow accumulating and followed by about a week of well below “normal” temperatures.

Environment Canada’s Edmonton Temperature “Normals”, presumably means daily high and low temperatures, but means are of little use in this climate. Measures of central tendencies in a truly normal distribution can be informative, but the weather here swings from one extreme to the next, often on a 10-14 [day] roll, and “normal” temperatures are rarely experienced except in passing. The snow stuck around for almost a week, frosts and flurries dominated the well below normal weather, and things looked bleak for the early bloomers and recently transplanted perennials.
But what do I know – except for a few burned branch tips and blasted tulips, most plants came through just fine. What most impressed me was the palm-leafed coltsfoot Petasites frigidus palmatus. Some plants avoid damage to their cells from ice crystals by shedding water when the temperatures plunge. This causes a loss of turgor - leaves and herbaceous stems become limp. Under the snow and even after the snow finally melted but the temperatures remained low, the coltsfoot looked like it had been beaten down by the weather. But it was just doing the obligatory obeisance to the Frost Gods. Perhaps to the Aztec god Itztlacoliuhqui, which Wikipedia tells me is best translated as "Everything Has Become Bent by Means of Coldness".

Since Wednesday 12 May, the temperatures have been well above normal, the snow is gone, the ground got a good drenching, and the bees and coltsfoot are together again. The heat has seeds and shoots popping up all over. The butterflies, beetles, wasps, hornets, and flies that also disappeared last week have reappeared with a vengeance – and the mozzies started biting yesterday 15 May, only a little on the late side (8-22 May is the range I have recorded). Although another cold front is undoubtedly waiting to swing through this week or next, one can hope it will just be coolly abnormal, maybe drop a little rain for the garden, and Itztlacoliuhqui will tend to his worshipers in the Southern Hemisphere until some time after the next equinox.