Friday, October 26, 2012

Not yet Native of the Week: English Daisy

A nymphal ('larval') Tarnished Plant Bug on an English Daisy
In south eastern Australia, the English Daisy Bellis perennis L. is very common, so common that without knowing its origin, one might think it native. Like the Dandelion, the English Daisy is low growing and rather impervious to lawn mowers. Hence another common name is Lawn Daisy (aka Lawndaisy). However, it does very well in national parks that have been over-grazed by too many kangaroos too. Although weedy in Australia and naturalized in much of North America, it is rather pretty and not especially noxious unless one is very much the purist about their flora. 
Overbred and not hardy, but nice
The wild forms quickly revert to a plain white daisy, but numerous often very attractive horticultural forms are available at nurseries and they bloom for a long time. Summer before last we succumbed to some of these attractions, although knowing of the daisy's weedy potential. Fortunately, a rather mild central Alberta winter proved too much for these well-bred daisies and nothing re-sprouted in the spring. I suppose that means we could try again next summer and enjoy a few months of pretty blooms without worrying about letting loose a weed. Well, assuming no hardy genes showed up.
The nymphs of bugs slowly develop their wings, moult by moult

Sunday, October 21, 2012

From Gladioli to Gobo: Flowers, Food & Friendship

1st Blooms of a hardy gladiolus - a gift from a friend
When we first moved to Alberta from sunny, frost-free Brisbane, the Home Bug Gardeners hadn't much of a clue as to what we could or should grow, just a vague idea about making our yard a nice place for bugs, birds, and people. We extirpated lawns and planted the major trees and shrubs under the guidance of our friend Adrian, but the rest was up to us. We wandered the local greenhouses with starry eyes, quickly disposed of our disposable dollars, and carted home many beautiful plants in ugly black plastic pots. We still have the pots stacked high in the garage, but hardly one of those early perennial purchases survives. As to produce, we got little: mostly woody celeriac, zucchini covered with downy mildew, and green tomatoes.
Leafy bounty at the Snagwood garden
Fortunately, we soon made friend with others of like mind and far more Zone 3 experience. The Currah's garden, Snagwood, is far outside the Urban Heat Island benefits of the city, but each year they raise a stunning bounty. Even better, they meld two horticultural traditions with an interest in experimentation and are happy to share it, even with strange bug people.
Red-leghorn & Snagwood's summer flowers
The first benefit to the HBG was Gladiolus imbricatus, the flower at the top of the post. The most recent, gobo (Arctium lappa), a crunchy and yummy root crop. In between, we've been treated to innumerable tasty treats, from ginger cookies to roasted rooster, and many lively discussions. We haven't been able to return much in kind, but we would like to devote a special issue of the Home Bug Garden to Satomi: some virtual vegetables, flowers, and chickens to wish you a happy birthday!
Salt, rice, saki from Satomi to Gopher Hill

Friday, October 19, 2012

Friday Bug: Pine cones, molehills, and gophers

Spruce with cones, snow, and setting sun
The Home Bug Garden is situated in the Aspen Parklands of Alberta, so although spruce trees (White Spruce Picea glauca and Black Spruce Picea mariana) survive in protected areas of the landscape, the natural fire frequency tends to keep them from dominating and favours the patchwork of grasslands and aspen forests that give the parkland region its name. So, for example, if you walk through the Saskatchewan River Valley, you might notice that spruce trees grow mostly on the sheltered, wetter north-facing slopes of the ravine - and in the parks and yards.
Strange "Pine Cone" on my spruce
Actually, you are likely to find many kinds of spruce growing in peoples' yards. The Home Bug Garden has White Spruce, Black Spruce, and (not a native) Colorado Blue Spruce Picea pungens. Like all members of the Pinaceae, spruce produce male and female cones, and each of these cones are distinctive. But our White Spruce produces a third kind of "cone" and although these look very much like cones, they are not 'pine cones' or even spruce cones, but Cooley Spruce Galls caused by an aphid-like bug Adelges cooleyi (Gillette, 1907). 
Developing Cooley Spruce Gall on White Spruce
Blue Spruce are often considered the primary host of the Cooley Spruce Gall 'Aphid', but like many aphids and aphid-like bugs, these insects have a complicated life cycle where they alternate between two different hosts. In this case it is usually a generation on Blue Spruce and then a generation on Douglas Fir (Pseudotsuga menziesii). In Edmonton Blue Spruce does fine in yards, but I can't say I've seen a Doug Fir hereabouts, perhaps because they are only marginally hardy (Zone 4). In any case, only our White Spruce produces spruce galls, so something strange is going on. Most likely a cryptic species or host-specific strain that can get by on just spruce trees is present and it just isn't enough of a pest to have stimulated the research needed to clarify the situation.
Very cone-like gall- but who is it fooling?
In any case, why these tiny bugs make homes that look like cones, I have no idea. Who do they think they are fooling? Well, they do fool most people, even some entomologists the first time they see one, but they don't seem to fool the squirrels. I have yet to see a Red Squirrel feeding on a Cooley Spruce Gall. Perhaps they are too stuffed with spruce seeds, acorns, and baby birds, but I think they know the difference between a gall and a cone.
Do Red Squirrels know a gall from a spruce cone from a pine cone?
Not knowing such a difference or using an  incorrect name are the kinds of things that tend to annoy scientists. So, although Adelges cooleyi was once an aphid (family Aphididae) and called the Cooley Spruce Gall Aphid, these strange aphid-like bugs are better referred to as 'adelgids' now that they have their own family, Adelgidae. Since it is a common name, though, 'aphid' can be argued to be as correct as it needs to be. But the local custom of calling cone-like structures on spruce trees 'pine cones' always leaves me perplexed. Logically, pine cones grow on pines and spruce cones on spruce! Yet, the common name for all cones in my neighbourhood is 'pine cone', no matter what kind of tree it grows on. I don't want to make a mountain out of a molehill, but when I hear 'pine cone' I expect to see one.
Neither mountain nor molehill, but pocket gopher mound
Speaking of molehills, Alberta has none. True moles are small, burrowing mammals related to shrews that feed on insects and worms. Alas, none of the six species of true moles known to live in Canada is found in Alberta. If something  that looks like a molehill is thrown-up in your yard in the Edmonton area, it is a mound created by a pesky, root and top-feeding Northern Pocket Gopher. Therefore, with irrefutable logic, I say this must be a gopher mound! Yet my neighbours looks at me and sadly shake their heads at the ignorance on display, tax dollars wasted, and say 'Gophers don't make mounds, they dig holes!'
If this head could speak, it would declaim: "I am not a gopher!"
"Those are ground squirrels, not gophers, Richardson's Ground Squirrels", I insist to yet more head-shaking. 'Squirrels live in trees. Those are gophers, or you can call them pickets if you want, but they don't make mounds. You can go to the Gopher Hole Museum in Torrington and see for yourself.'  is the response that I get. 
If you can't beat 'em, join 'em: Two Gophers in Torrington, AB
About then, things are starting to get uncomfortable. Either the neighbour thinks I'm an idiot or that I'm pulling their leg. It's time to talk about the weather - something that everyone agrees on. It's as obvious as the snow on your cap or the picket in the pasture.
Gopher, Picket, or if you're argumentative, Ground Squirrel

Monday, October 8, 2012

Flies for Thanksgiving

A pair of Leafminers (Liriomyza sp.) celebrate Spring in the Home Bug Garden
Thanksgiving is a time for giving thanks for many things; but historically, a good harvest has to rank near the top. In the Home Bug Garden the harvest is what the hail, drought, floods, frost, slugs, pathogens, birds, and bugs have left for us to eat. Of all of these kleptoparasites and vagaries of the weather, the bugs steal the least. The caterpillars of the Cabbage White Butterfly devastate my kohlrabi and kale. Flea beetles and root worms prevent me from growing broccoli, turnips, and radishes. Leaf miners make chard, beets, and spinach unprofitable use of limited space. But most other insect 'pests' don't do enough damage to make a difference. I suppose that is one advantage of gardening in the cold, short growing seasons of Zone 3.
House Sparrows do more damage to peas in the HBG than leafminers
The pair of mating flies at the top may be one of those minor HBG pests, perhaps the same fly that makes leaf mines in my peas. But unless I use row covers, the House Sparrows eat most of the young peas leaves, so pea leaf-miners are rather rare and more interesting than pesky. These particular Leaf-mining Flies (Agromyzidae) belong to the very large genus Liriomyza which contains many of the important agricultural pests. The family itself is very successful - the third largest family of acalyptrate flies according to another of my reasons for giving thanks today: a new book by Steve Marshall: Flies, the Natural History and Diversity of Diptera (2012, Firefly Books) and the time to peruse it. And not just agromyzids, but 10 other families of Diptera have maggots that munch through the middle cell layers of leaves.
Lauxania shewelli Pérusse & Wheeler, 2000
Maggots munch dead leaves to, as demonstrated by another highly successful family of acalyptrates (i.e. 'higher' Diptera with an organ called a ptilinum but without calypters) the Lauxaniidae. Like many Diptera, the larvae of Lauxania shewelli Pérusse and Wheeler, 2000, feed on decaying matter. I'm not sure exactly what detritus Lauxania maggots feed on, this is often the case when a fly has not come under close scrutiny for eating us or our livestock or our plants, but many lauxaniid maggots have the interesting habit of mining dead leaves. Adults scrape spores and mycelia of fungi from live leaves (Marshall 2012), probably what is going on in the picture above. As Steve Marshall points out, adult flies are not known for eating leaves - they seem to never have managed that evolutionary leap.
Scathophaga cf stercoraria (Linnaeus, 1758) predator as adult, saprophage as maggot
So we have numerous maggots that find leaves, dead or alive, perfectly acceptable as food, but no adult flies with the ability to eat vegetation. I find that curious. Many flies, like the Golden Dung Fly Scathophaga cf stercoraria (Linnaeus, 1758) above, are predators of insects that piece and suck their haemolymph. Far too many flies have the ability to suck our blood. But adult flies don't eat leaves or suck the sap of plants, unless it is oozing from a wound. I guess that is something else to give thanks for.
Lecanocerus compressiceps Borgmeier, 1962
Well, there is the caveat that we don't actually know what all that many flies do. Take the Scuttle Fly (Phoridae) aboveLecanocerus compressiceps Borgmeier, 1962. Unfortunately, the common name 'Antler Fly' is already taken by some fascinating little flies that feed only on the discarded antlers of moose and deer and a strange fruit fly from New Guinea. The generic name 'Lecano-cerus' seems to mean 'plate-horn', which is descriptive, but hardly evocative. I'm sure these male ornaments are used for something interesting, but google and Marshall both fail when it comes to explaining just what. Yet another mysterious fly! Well, nothing so interesting seems to be on the wing at the moment and I'd better do something with all those harvested tomatoes before they turn into dew-loving flies. So Happy Thanksgiving to all my Canadian readers!
A plate-horn to the genus author, but an Albertan Antler Fly to me

Friday, October 5, 2012

Bee Gone until Spring: Itztlacoliuhqui Returns

Two well worn Leaf-cutter Bees making sunflower seeds as the Equinox looms
Alas, Itztlacoliuhqui has awakened and the season of hard frosts has begun. It seems peevish to complain after what seemed a relatively long and mild Autumn, but was it? Determining the First Fall Frost isn't as easy as it sounds given the variable nature of climate, the movement of winds, and the effects of concrete and buildings. Officially, frost is when the air drops to 0 degrees Celsius at 150 cm above the ground as measured in a standardized instrument shelter. These weather stations tend to be located at airports or other official facilities. The Alberta Agriculture and Rural Development site gives the average First Fall Frost Date for three such facilities around Edmonton: the International Airport (Sept 10) located in the open fields well to the south of town, the Canadian Forces Namao Base downtown (21 Sept), and Stony Plain (21 Sept) well to the west. Another commonly given date is for Edmonton's FFF is 23 September, just after the Autumnal Equinox.
Leaf-cutters use their hairy bellies to hold pollen, something sunflowers must appreciate
The Home Bug Garden isn't particularly close to any of the official sites and doesn't have an official weather station of its own. What I use are a thermometer on the porch railing, the garage roof, and the crop plants originating in South America to determine First Fall Frost and First Killing Frost. This year the first frosty roof was 16 September (thermometer < 1 C). The average for the last 8 years is 12 September (range 28 Aug to 23 Sept). The beans, tomatoes, and peppers died on the morning of 4 October (-4 C). The average for the Killing Frost for the last 8 years is 2 October (range 17 Sept to 15 Oct). I guess a week or two after the Equinox is the best I can expect.
Scarlet Runners, tomatoes and peppers know when Itztlacoliuhqui has returned
So, this Autumn hasn't been unusually long. I guess it just seemed that way by way of memories of previous less pleasant Septembers. Another influence has been that the flowers have been essentially bee-free for two weeks. Flowers with no bees seems wrong, and the few honeybees to be found don't make it quite right. I don't begrudge honey bees the bit of honey they may make, after all they've just been robbed of their summer's savings and have nothing but sugar water to look forward to until spring. But where are the native bees?
Where have all the bees gone? Gone to graveyards every one?
Sadly, most bees have a life that is nasty, brutish, and short. Well, short at least. It's hard to think of days wallowing in flowers as being all that brutish and they do seem to enjoy their work. Bees never seem bored, at least not until late in the season. Then they do tend to bludge a bit, but by then they are old and worn as the tattered wings in the pictures of the Leaf Cutter Bees (Megachile sp.) above attest. Most of our native bees are active for but one season. They spend the winter in an immature stage (typically a pupa) in a nest, emerge from their nest holes in the spring or summer, make plants set seed and new bees grow for as long as they can, and then die.
Cleptoparasite Coelioxys - a bad bee if you are a Megachile
Not all of their nests will produce new bees in the spring, or at least not the bees that they hoped. Some will freeze, some will dry out, some will be dug up, some will turn into fungi or bacteria, and some will transform into different kinds of bees or wasps or flies or other kinds of parasitic insects. Our leaf-cutter bees have to run the gauntlet of all of these woes, but perhaps the most insidious club-strike is the robbing and murder by Cuckoo Leaf-cutter Bees in the genus Coelioxys. These bees invade a nest of a Megachile (a close relative), deposit their own egg, and their larva then eats the provisions collected by the Megachile and kill her young. As fascinating as this 'theft parasitism' (kleptoparasitism) may be, I'm sure that even Aesops would have found it difficult to draw a moral lesson. 
Spring and this Megachile wants what the Bombus borealis is monopolizing
Oh well, at least some bees build their own bed of roses and some get to see both Fall and Spring. Bumble bees (Bombus spp.) are an exception to the work hard and die in the Fall of beedom. Worker and drone bumble bees are all pretty much at permanent rest now, but next year's queens are huddled down in an old mouse burrow or some other refuge waiting for next spring. Unless someone accidentally digs one up while gardening, these queens will emerge as early as warmth permits and start new colonies in May. A bit later the Megachile that survived will emerge and join the growing legions of busy pollinators, and of course, their parasites and predators. And Itztlacoliuhqui will go to sleep until around the next Equinox.
Mystery male parasitoid enjoys the summer's bounty