Plant of the week... Eriogonum

As some of you may know, I am still not done with my thesis. I fell into the trap of getting a full time job before I finished. Many of my friends fell into this same trap, I guess I the high cost of living is the main cause. The problem with working a full time job is when you get home the last thing you want to do is work on a thesis. But I have found the time and I am almost done with the next round of edits. I have been struggling on proving what insect visitor pollinates my flowers.
On Monday, I made progress.

A little background... My thesis deals with pollination of dioecious Eriogonum. I compared 3 species of Eriogonum, E. diclinum, gynodioecious, E. umbellatum var. modocense, and hermaphriditc E. u. var. argus.

Here is a photo of a male E.diclinum inflorescence

and here is a photo of a E. u. modocense inflorescence...

On Monday I took my flowers and select insects to the Scanning Electron Microscope we have at the academy. I was able to take amazing photos of pollen grain by themselves and on the insets. The photos are amazing. Pollen grains for E. diclunum look like blunt footballs.

Pollen grains for E. u.modocense have a similar shape but are more pointed and have less of the dimples. The SEM is amazing. These single pollen grains are on the scale of microns but we were able to take photos of their texture. Quite a handy tool.
One of the main floral visitors was this guy. Lopidia sp. Here is one on a E. diclinum inflorescence. Even though the insets were very common, my observations showed these guys were not good pollinators. Their foraging behavior on the flowers did not seem to indicate they were great at moving pollen from flower to flower.
The SEM showed this may actually be true. This photo of the head of a Lopida is sparsely hairy and no Eriogonum pollen.
What the observational data showed was a small beetle, Amerocerus sp. is the main pollinator. This small beetle collects pollen on its head and thorax. When foraging, these are the areas that come into contact with the stigmas which would mean successful pollination.

This photo is one of the beetle covered in pollen. But what kind of pollen?

The SEM took a great photo of the insect body.
but a closer shot indicated all the pollen grains were the same.

We need to take more photos of other insects but the results look good. These photos show Amerocerus is main pollinator. All these pollen grains look like they are from E diclinum flowers which is also good. Amerocerus sp is the main pollinator for E. diclinum and these photos strengthens my argument. Success