Friday, May 02, 2008

oil beetles


This is the female of the violet (or bluish) oil beetle (Meloe violaceus). Spot reads that this unusual beetle lays its eggs on the ground in leaf mould (as here). These hatch into long legged small larvae (triungulins) that swarm over plants in hot weather (they may have to wait a long time this year). They then attach themselves to a wild bee and are carried back to the bee's nest where they set about devouring the eggs and grubs. As they change into grubs themselves they eat the honey. They pass the winter as fat headless legless maggots then metamorphose one last time and crawl out in the Spring as adults to feed on buttercup plants. They also act as models for Alien. When picked up or otherwise irritated by inquisitive dogs they exude a foul fluid from their joints. They have overlapping wing cases. This one is distinctly blue.

6 comments:

Anonymous said...

Spot,

Thanks for letting me enter the fascinating world of the blister beetle. The young larvae are also known as triungulins after their three claws. A new word for me: hypermetamorphosis. Each growth stage of the blister beetle is different in appearance and habits. Apparently, some members of this family are traditionally used to make aphrodisiacs and other drugs.
Is there such a thing as Cornish Fly?

spot said...

We did wonder about that; doombar perhaps. is that the correct spelling of Tri(u)ngulins. It certainly makes more sense than tringulins which sounds like something they might ride round on. Interestingly, it is similarly spelt in several web sites. I will check.

spot said...

triungulins it is...they can even make themselves into the shape of a bee. Amazing.

Anonymous said...

Spot,

This paper has a couple of clips in the supplement:
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1599908

As you say, amazing.

spot said...

I had already read the precis of the paper in my search for the correct spelling and found the pictures of triungulins trying to look like bees. As I understand it the imitation is more apparent than real and male bees are actually attracted by a pheromone given off by the hypermetamorphosing cunning little imps. The fact that we can access the same paper by different routes goes to show how interconnected we have become and how easy it is to get information; even more amazing. Bees around here seem unusually sluggish to me, is something affecting them?

Anonymous said...

Hi Spot,

Maybe the temperatures are not warm enough quite yet for the bees? Or are they just reflecting a more relaxed approach to life than previously?