Friday, June 29, 2012

Thursday Blue Butterfly

Puddling Silvery Blue
It's always nice when an insect lives up to its name and the small blue butterflies now common around fields with Wild Vetch and Creamy Pea Vine are called Silvery Blues Glaucopsyche lygdamus (Doubleday, 1841). The males are more silvery and, perhaps, more likely to be seen, since they patrol the areas around the plants that their caterpillars would like to eat.
Silvery Blue exposed
The reason that butterflies, and especially male butterflies, may be found sipping mud rather than flowers (a behaviour called: puddling) is a bit obscure, but seems to be somewhat similar to taking vitamin pills in humans. Essential nutrients and salts not overabundant in the larval food, mostly plants, may be present in wet soil or less savory (to us) wet organic substrates. Males have a hard life flying back and forth, chasing away other males, and chasing females, so a puddle of mud may be a pleasant and invigorating break.
Silvery Blues are grey and spotted underneath
The reason for the often striking differences between the upper and lower wing surfaces of many butterflies is a bit obscure too, but one reason is most likely obscurity. It is easier to blend into a background when not boldly coloured, especially if the colour can suddenly disappear with the fold of the wings. Flashing the upper colours may also be useful to startle enemies, tell other males to get lost, and advertise one's beauty to the opposite sex.
Nectering is good for the vetch, but leaving behind eggs, maybe not so good
Energy for all the fluttering activity comes mostly from nectar and the butterflies may pay the plants back for their sugary rewards by transferring pollen. However, this Wild Vetch might much rather be pollinated by one of the bumble bees or carpenter bees that also were visiting, because the larvae of the Silvery Blue feed on assorted wild legumes such as this vetch. As the caterpillars feed they secrete a sugary substance that is very attractive to ants. The ants become addicted to their tasty reward and vigorously defend the larvae against other insects, including parasitoids. That seems a pretty exceptional life history, but if you look closely enough at any insect and you are likely to find equally unexpected and fascinating stories.

Sunday, June 24, 2012

Adventures in Spider Misidentification: Sac Spiders

Sac spiders don't mind the dew
Ever had one of those nights when you had too much fun and awoke the next morning damp with dew? Well, looks like it can happen to Sac Spiders too. At least we think these are Sac Spiders, male to the left, female to the right, in the family Clubionidae. With only two genera in our area, we have a fifty-fifty chance of being right in calling these damply amorous two Clubiona, Leaf-curling Sac Spiders, but that requires the assumption we have the right family.
Sac Spider or Ground Spider?
We used to think this wandering female might be a Clubiona too, but now wonder if it isn't a member of the highly diverse Ground Spider family Gnaphosidae?
A curled leaf?
Well, when in doubt, stick to some definitive character if you can find one - and Leaf-curling Spiders should curl leaves, right?
And what lies in wait?
What else but a Leaf-curling Spider Clubiona sp.!
Well, Clubiona, no doubt, but the species still remains uncertain. It didn't feel right collecting mom before all the kiddies had hatched, at least not with any purpose better than idle curiosity. So, someday a pit fall may give us a definitive answer, but for the moment we are happy with Clubiona.
A young Clubiona? Maybe or may be not.

Friday, June 22, 2012

Bee-learned, not Bee-clowned: White-tailed Bumble Bee vs Globeflower

Bombus moderatus thinking about food
What does one do when a week of lectures need to be revised, a paper finished, hundreds of identifications proposed, dinner cooked, and a host of other chores gathers on the horizon? Why watch bees learn, of course.
The examination begins
Without flowers, flowering plants would have no offspring, or what they had would be monotonously similar clones from generation to generation. Ergo, one might assume that those plants that require insects for pollination would not be shy about initiating the mating dance. But many flowers seem to be of two minds, proclaiming 'here I am, come get me' but providing no obvious means of ingress. Bottle Gentians are one well known example of such coy flowers, and the European Globeflower seems to be another.
And she's in!
But things may not be all that they seem. In Finland and the European Alps, the Globeflower has been shown to have an obligate pollination relationship with Globeflower Flies (Chiastocheta spp., Anthomyiidae). Both sexes of the flies penetrate the flower, females lay eggs, and the resulting maggots eat the globeflower seeds. Globeflower must feed many of its offspring to maggots to ensure that some survive. That's all well and good (if creepy) in Europe, but how about in the Home Bug Garden where horticultural varieties of globeflower abound, but the flies seem to have missed the boat? One of the great advantages of bumble bees (Bombus spp.) as pollinators is that they can learn to pollinate even the most indifferent of flowers from beans to buzz pollinated peppers to bottled gentians to horticultural globeflowers.

Friday, June 15, 2012

Pollinator of the Week: A Buzzing Bonanza

Scots Rose & White-tailed Bumblebee
June can be  beautiful month in Edmonton, or so they tell me. In my experience, the beauty comes in small doses, with the breaks in the clouds as rain-laden low after low rolls across. Oh yeah, I know, I'm always whinging about the weather here, but take a look for yourself.
When the sun does break through, though, things start popping. In the first two weeks of June, it is the Scots Rose (Rosa spinonissima 'Grandiflora') that pops the most. Our heirloom monster came with the house and is about 4 meters of spiny canes in every direction. Sometime between June 1st  and 16 June (the cold spring of 2009), the thorny mound becomes covered with large (7-8 cm diameter) single white roses - and bees galore, at least when the sun is shining.
The new, and currently most common, Bombus in town
Wednesday afternoon the sun was shining and the bees buzzing. The most common was also the most recent addition to the Edmonton Bumble Bee Fauna: the White-tailed Bumblebee, variously known as Bombus cryptarum, lucorum, and moderatus. The genetics seems to favour the latter, so that is what I am sticking with.
Red-belted Bumblebee Queen
Although apparently the most common bee at the Scots Rose - and with unusually large workers for this time of year - the White-tailed was only one of at least 6 species of Bumblebee harvesting the pollen and nectar.
Half-black Bumblebee worker
Second most common was old-reliable: the Half-black Bumblebee (Bombus vagans), both queens and new workers. But also present were queens of the Red-belted Bumblebee (B. rufocinctus - thanks to John Ascher for the id), the Tricoloured Bumblebee (B. ternarius), and a single queen each of the Yellow-banded Bumblebee (B. terricola) and what I'm tentatively calling the Black-and-Gold Bumblebee (B. auricomis). The latter seemed more interested in the lilacs, but was not above a blurry dive into a rose.
Maybe Black & Gold Bumblebee
But wait! There's more! A half-dozen or more other bees were also harvesting the bounty.
Halictus rubicundus - Banded Sweat Bee
A large and a small species of sweat bee (Halictidae) were zooming in and out and I'm pretty sure the larger one was Halictus rubicundus. She seems to lack a common name, but I will call her after her most striking character: the Banded Sweat Bee.
Leaf-cutting Bee Megachile sp.
A leaf-cutting bee was also in on the harvest, although collecting pollen on the underside of her abdomen, rather than on the hind legs. Then there were all the mystery bees.
Mystery bee in Scots Rose
Perhaps anthophorines, perhaps andrenids, perhaps halictids. Who knows? I think one may have been a yellow-faced bee and another an Andrena. There was so much rapid buzzing in and out that it was hard to keep track, but at least a dozen types of bee ended up in my notebook.
Probably a Digger Bee Andrena sp.
Alas, bees were not the only animals on hand to share in the bounty and not every bee made it home to its nest.
Digger bee becomes one with Misumena vatia
Oh well, it's not a Disney world in the Home Bug Garden, and there seemed bees enough for flowers and crab spiders.
Small worker of, maybe, B. centralis or flavifrons
Well, yet again, the showers have stopped for the moment and the sun is shining. Time to push through the wet vegetation and see if something interesting is buzzing about.
Rosa spinonissima 'Grandiflora'

Sunday, June 10, 2012

Adventures in Spider Misidentification: Strife or Pearl?

Balloon Flower in balloon stage with male jumping spider
Rain is a drag, especially on weekends, but rainy periods are good for gardens and excellent for transplanting. Unfortunately, the Home Bug Gardener doesn't like getting wet and absolutely cringes at the thought of black clay mud. Thus, a certain discord reigns during extended rainy periods. Yes, I just disposed of my disposable income on perennials to replace those that died this winter. Yes, now is a perfect time to plant them out. No, I don't want to get any damper and muddier than I am now. Ergo, I offer a spider that may be an Eris CL Koch, 1846, apparently named for the Greek Goddess of Strife and Discord.
Perhaps the spider of Military Strife?
My best guess is that this ballon-flower-perching male jumping spider is Eris militaris (Hentz, 1845). It looks about right and the species is known from Alberta. However, there is another genus of Salticidae, Pelegrina, that looks very similar, especially P. exigua (Banks, 1892). 'Exigua' is Latin for 'small', and this spider is small. Pelegrina Franganillo, 1930, however, is obscure. Perhaps, it was named for the famous La Pelegrina Pearl, whose history is almost as fascinating as that of the Maltese Falcon.
Two Balloon Flowers
Well, I'm not the one to give a definitive spider identification and perhaps some reader will offer a more expert opinion. I do, however, claim that the perch is in fact a Balloon Flower, Platycodon grandiflorus (Great-flowered Broad Bell). Balloon flowers come up very late, so I'm not sure if my exemplar survived this winter or not. However, I know the last Viburnum trilobum has succumbed to root crown borers and that two Northline Saskatoons were victims of Wooly Elm Aphid. I suppose it is time to get muddy.
Balloon flower opening

Saturday, June 9, 2012

Wildflower of the Week: A Mystery in Spurs

Spurred mystery plant
Last summer Mrs Home Bug Gardener and I, while walking a trail on our land that we had traipsed a hundred times before, encountered a plant that we'd never seen before. We had no idea what it might be, but it was very strange indeed: purplish, spurred, and square-stemmed with somewhat fleshy opposite leaves - more like a visitor from another planet, than a normal denizen of the Great North Woods.
Scrophulariaceae, not
Alas, none of our pretty picture books of Albertan flowers was of any use. So, it was off to the flora of last resort: EH Moss's completely picture-free Flora of Alberta. Alas and alack, it wouldn't key to family! Not a mint, not a snap-dragon (Scrophulariaceae - the family I thought most likely), not any of the families with 4 stamens and 4 petals! That left only leafing through each family and trying the generic keys - and final success on p. 455: Halenia deflexa (Sm.) Griseb., American Spurred Gentian.
American Spurred Gentian Halenia deflexa
Well, gentians aren't always 5-merous, a good thing to know, and finding a flaw in a key always makes me feel virtuously smug, but why spurs? Obviously there must be some interesting long-tongued pollinators coming to the spurs. So, off to the literature - for a frustrating round of fruitless research. Although there are 22 species of spurred gentians around the world, and one is considered an important medicinal plant (Tibetan Medicine - Halenia elliptica), and there are many papers published on the anti-oxidants the plants possess, their pollination ecology is a complete mystery!

KB von Hagen & JW Kadereit. 2003. The Diversification of Halenia (GENTIANACEAE): Ecological Opportunitey versus Key Innovation. Evolution 57(11): 2507–2518 

Wednesday, June 6, 2012

Wet Wednesday Beetle: The Firefly that couldn't

A firefly that flies, but doesn't fire
The genus name, Ellychnia, of this luminescently challenged firefly (a beetle in the family Lampyridae) apparently is derived from the Greek for a lantern or lantern wick, but it has no light-making organ. I suppose the common name of Diurnal Firefly gives us a hint of why this may be so. We call this beetle Ellychnia corrusca s.l. The appendage stands for 'sense broad' in Latin (sensu lato), because 'corrusca' seems to be a complex of species.
Ellychnia corrusca or a close relative
Diurnal Fireflies are common on flowers such as goldenrod in the fall, overwinter as adults, and show up early in the late central Alberta spring. Although they don't shine, we like them anyway. At our place in the country, there is a firefly that shines in the vegetation along the shores of the lake and marsh. This is undoubtedly a species of Pyractomena, Alberta's only glowing glow-worms, but which of the two species we are not sure. I suppose some summer night we should brave the bog and beavers and try to get a picture and specimen. But so far, we've just been happy to watch them flicker in the dusk.

Friday, June 1, 2012

How to know a fly: Mozzies & Midges

Male midge: plumose antennae, no beak
For the last few weeks the woods near lakes and rivers have been humming with midges. In spots where they swarm in numbers, the noise can be loud enough to cause comment and the size of the swarms may cause dread in those who confuse them with mosquitoes.
Male mosquito: plumose antenna + beak
Fortunately, midges (Chironomidae) do no harm and are integral parts of aquatic ecosystems. Like mosquitoes (Culicidae), male midges have plumose antennae used to follow a female's hum, but they lack the long beaks in between that define mosquitoes. Not that anyone need worry about being bitten by a male mosquito - they use their beaks to feed at flowers and do not take blood.
Female Ochlerotatus spencerii - arrow points to proboscis, stylets inserted
In the Edmonton area, we mostly have two types of mosquitoes. Species of Culex, Culiseta, and Anopheles overwinter as adult females and start biting in the spring. I sometimes see one in my backyard in the spring, but rarely. Usually they don't start showing up until later in the year. I think this is because they breed in lakes and marshes and it is a long way from the HBG to the closest lake. Around Elk Island, though, some of the very large and rather scary Culiseta have been landing and trying to bite the last two weeks. Fortunately, they have been few, rather clumsy, and mostly ended up as splats.
Female Aedes vexans - our most annoying puddle mozzie
The second type of mosquito is the snow melt/ flood water breeders in the genera Aedes and Ochlerotatus.  These overwinter as eggs laid in wet soil next to puddles of water from melting snow and heavy rains. The eggs need to be flooded to hatch. I keep track of when the first of these start biting in the Home Bug Garden and this year it was 14 May - intermediate between 8 May (2005) and 22 May (2009) - another indication that this is a moderate Spring. The other good news is that only one mozzie has shown up so far.
Male mozzie waiting for flower to open or female to fly by
After last year's horror mosquito summer, it seems a blessing, but a bit strange, that there have been so few snow melt mozzies. Perhaps the City's mosquito abatement program is working very well this year. Alternatively, the small spring snowpack and relatively dry May may mean that last year's eggs are sitting high and dry around the rims of last year's much larger puddles. I suppose that if we get heavy rains this summer, we will find out, but that is one hypothesis I'd rather not test. Especially, since there is another kind of mosquito, Culex tarsalis, that breeds in grassy puddles in the summer and transmits the West Nile Virus.