Sunday, December 16, 2012

Adventures in Spider Misidentification: The Ravenous Ravened

A young orb weaver is more than a match for a Ravenous Leaf Beetle
I think this is a very young orb weaver, but I could be wrong. The web looks more crosshatched than orb-like, but I think I see radiating strands. In any case, the body sorta looks right (but remember the title of this series). I'm more sure about the victim, having spent much time and effort sorting it out: a Ravenous Leaf Beetle Orsodacne atra (Knoch in Ahrens, 1810).
3 pairs of Orsodacne atra being a bit excessive in a saskatoon flower
The colour patterns in Orsodacne atra vary quite a bit, but all are now considered to represent one species. The common name seems a bit off, but presumably somewhere some species in this family voraciously plunders a plant that people value. Orsodacne atra has been reported from birch and willow, but more as a curiosity than a pest. The adults, however, do seem to 'raven', i.e. devour voraciously, the reproductive parts of flowers, especially in the Rosaceae. 'Raven' and 'ravenous' come from the Old French raviner - to take by force, via the Latin rapina, from which we get several terms for unfettered excess.
A pair of Australian Ravens (Corvus coronoides) up to no good
Surprisingly, though, the crow-like bird called a 'Raven' (Corvus corax
Linnaeus, 1758comes to use from a different origin: Old High German, Middle Dutch, and Old English equivalents of raban, the name for a big, black bird. So, even though ravens are known for plundering, Danish Vikings flew a raven flag, and many cultures fear ravens as bearers of ill omen, the similarity in words is a coincidence. The Raven is one of the few large birds to brave the Alberta winter and when they start moving into town from the countryside (once the Crows [Corvus brachyrhynchoshave moved south), you know winter has arrived.
American Raven with classic wingspread and boat-tail

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