Sunday, October 30, 2011

A long reach: Daddy-long-legs aka Harvestmen

Meet Phalangium opilio Linnaeus, 1758
I've been trying to decide if a Daddy-long-legs would make a good Halloween costume, but I think the 'face' would be too strange to be scary and the legs far too long and cumbersome for walking around.  Even capturing the legs in a photo of the body can be a problem.
Phalangium opilio has only one generation a year in the Home Bug Garden. At the moment they occur only as eggs hidden in the soil by the ovipositor of the female. In the spring, usually in late May, the tiny young can be seen scurrying around the garden, but one has to look closely to see them. By the end of June they are large enough to be noticed as they nonchalantly wander around feeding on small live insects, dead insects, bits of rotting fruit, and probably from pollen in the flowers they frequent. By the harvest season, they seem to be everywhere, and hence, their other common name.
Daddy-long-legs live up to their name - a front leg, about 6x the length of the body, reaches into the upper left corner of the picture.
Alberta is home to a half dozen or more 'native' species of Opiliones, the order of arachnids to which the Daddy-long-legs belongs, but our species isn't one of them. Phalangium opilio apparently came from Eurasian with the more recent waves of Eurasian colonists and, like the sowbugs in last week's post, is found mostly around people in cities and suburbs. We quite like ours, and can't see any reason not to. They don't bite, they don't bother, and they don't do any damage to the garden. Besides, I was told as a child that if you are lost, catch one, and knock off a leg, it will twitch in the direction of home.
Alien but inoffensive
Several other arthropods are called Daddy-long-legs including flies in the family Tipulidae and spiders in the family Pholcidae such as Pholcus phalangioides  Fuesslin, 1775. These arthropods are easy to tell apart since the spider has a spider's waist and the crane fly has a pair of wings, unlike Phalangium opilio, which has neither waist nor wings at all. We have lots of craneflies in Alberta, but I have yet to see a daddy-long-legs spider. Although this is another of our arthropod synanthropes that have been moved around the world by people, they haven't made it to our basement.
Another kind of daddy-long-legs: Crane Fly (Tipulidae)
A bit of sun, an absence of wind, and the promise (but not yet the reality) of double digit temperatures (in Celsius) this Sunday, perhaps the last positive double digits we will see until April. Good reasons to get out into the garden, or what is left of it. Alas, it is a sad day for the birds - we have taken advantage of the relative warmth to turn off the bubbler, break the crust of ice, and pull the pump and filter out of the pond. The birds will continue to return for a couple of days, peering down the fountain hole, but no more water will be forthcoming until next spring.

1 comment:

  1. I know this isn't a very scientific response but here it is: I'm just glad they are small! :)