Saturday, May 30, 2009

Beetles up to no good: Natives & Not in the HBG

Last night a Frost Warning was in place for the International Airport, but the City Centre was predicting a safe 6C. Since the Home Bug Garden is about halfway in between these two weather stations, and sometimes closely follows one more than the other, out came the old towels, throws, and sheets. In any case, we came through with a low of +4C (39F), about midway between the 1 & 7C reported at the two airports this morning. Being intermediate is more or less ‘normal’ here, and the HBG once again benefited from an ‘unnatural’ modification of the climate, an Urban Heat Island Effect (although not as strong as I would have wished). My friend in Gardening Zone 3b lives nearer the City Center, as one can seen by the numerous beautiful blooms with which his garden has already been blessed.

The Home Bug Garden is getting there, though, and has a few beauties of its own. The Buffalo Currants (Ribes odoratum) and Golden Currents (Ribes aureum) are our alternative to forsythia (an iffy plant in this climate) – covered in attractive yellow blossoms in early spring and with the added delights of a clove-like fragrance and tasty black berries. Some people think these two very similar plants are the same species and the USDA database lists the former as a variety of the latter. There is a difference that some might think important, however; Buffalo Currant (Ribes aureum var villosum) is not considered ‘native’ to Alberta, although Golden Currant (Ribes aureum var aureum) is. UPDATE - Just checked our two forms and the picture was mislabelled - now corrected to Buffalo Currant, which seems to have brighter orange dots in the flower centre and long hairs on the leaf petiole (and hence, one assumes, villosum) that are absent in Golden Currant.

Cold or not, the currants, cherries, marsh marigolds, pasque flowers, and numerous bulbs are in full bloom. That should be good, since the HBG was started with pollinators in mind and stocked with lots of plants that would get them off to a good start in the Spring. Several years ago the HBG would have been abuzz in assorted bees, flies, wasps, and beetles flitting or crashing from flower to flower. Unfortunately, the last couple of Springs have been cold and treacherous and this year pollinators are few and far between: an Andrena or two, a couple of hoverflies and small wasps, and bumblebees – but only the few queens just starting their broods. One wasp of interest; however, was the small, hollow twig nesting moth-hunter Lestica producticollis, a new record for the HBG. Less welcome is yet another beetle, one that eats spruce.

Yet to make an appearance is a most attractive soft-winged flower beetle (Melyridae) called the Scarlet Malachite (Malachius aeneus): a spectacular little scarlet and metallic green beetle, often aggregating in open flowers (marsh marigolds, poppies) and dusted in golden pollen (the picture is from last year on a fleece flower spike). One would guess that any insect with a common name would have at least one striking feature and that goes double for one that makes a conservation list. Once “local but widespread” but now rare in England, the Scarlet Malachite has its own Biodiversity Action Plan. Here, of course, it is an alien invader, and as someone who has worked on ‘invasive species’, I tend to always assume the worst about any ‘alien’. I don’t know how this clear cultural bias inserted itself into my otherwise (in theory) ruthlessly scientific mind. It must have been too much exposure to bloody cane toads, lantana, bumblebees, hornets, foxes, hares, and assorted other neo-Australian miscreants. For example, when my wife pointed out an article (BBC Wildlife June 2009, p. 62) about an extinct UK bumblebee (Bombus subterraneus) being re- introduced from exotic populations in New Zealand, my first response was a snarl at the ‘threat’ the same population posed to Australia. Or does it? I think this problem deserves its own post or three, so for now I will just say that I hope the Scarlet Malachites are just late this year and not all frozen.

Meanwhile we have some interesting beetles showing up, most more or less native as far as I know, if ‘native’ means apparently living in Alberta before European people arrived (but not too much earlier unless they fed on ice). The willow (actually an exotic Golden Willow – Salix alba probably ‘Vitellina’) seems to be supporting an interesting array of ‘native’ chrysomelid beetles. According to Laurent Lesage, a specialist on leaf beetles at the Canadian National Collection, the Chrysomelidae has about 50,000 known species of which about 1% (566) are known to occur in Canada and Alaska. Several of these are introduced pests – like the all too common and diverse flea beetles – and some are someone else’s problem, like the striking 12-spotted asparagus beetle (we don’t grow asparagus, so we just enjoy the beetle as it passes through to wreck havoc on a neighbour). The ‘native’ willow beetles can do a fair amount of damage too, but not so much that the willow seems to suffer – it is growing far too well and putting on at least a metre a year.

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