Ambrosia Beetle Portrait

svalley · Post by **svalley** » Mon Jan 01, 2007 11:49 am

This is Gnathotrichus sulcatus (LeConte). It belongs to the bark beetle family Scolytidae. The common name is the Western Hemlock Wood Stainer. The male of this species carries 3 different symbiotic fungi species in enlarged cavities in the forecoxa. Their larvae eat the fungi. Beetles that infect wood with fungi are generally called Ambrosia Beetles, even thoght they may belong to different beetle families.

I shot this image to illustrate the fan shaped grooves on the frons which are used to differentiate it from a close relative Gnathotrichus retusus. Note how the prothorax surrounds the head, almost like a helmet.

Leica MZ16 stereomicroscope w/extended depth of field imaging system

beetleman · Post by **beetleman** » Mon Jan 01, 2007 3:43 pm

That is a very strange looking beetle Steve. I we looking at the top of the head or underside? These beetles always remind me of small tunneling machines. What they eat up front in the wood comes right out of the back

They are small beetles and I have never looked that close at the head until now. Great shots on these.
Welcome to the forums also, We have a great group of people who really enjoy what they are doing. Please make yourself at home.

svalley · Post by **svalley** » Mon Jan 01, 2007 5:08 pm

Doug, this a ventral shot. Their mouth points downward. You cannot even see their head in a dorsal view. These guys produce galleries in the wood, but they do not actually eat the wood. They eat the fungi that they infect the wood with.

Thanks for the welcome.

Ken Ramos · Post by **Ken Ramos** » Mon Jan 01, 2007 6:41 pm

This is one awesome photograph, your gonna fit right in here, no doubt

That thing caught me off guard at first. I thought I was looking down the throat of some nasty little critter with needle sharp teeth and a round Charlie Brown head, until I noticed the eyes and where the antennae were positioned. Some shot SteveV!