What are all the black specks in this thistle head?

The prairie is covered this week in shining flower beetles (Olibrus, in the family Phalacridae). They are aggregating in nearly every composite flower head, with a fair number just floating about among the grasses. The adults feed on pollen, and their sheer numbers make me wonder if there will be enough pollen left over to perform the plants’ reproductive functions. Here are some shots from Meadowbrook park.

Scaling the stamens

Getting busy.

Olibrus, up close

photo details
Canon EOS 7d camera
(top 2) Canon 100mm f2.8 macro lens
ISO 800 f/5.6-f/10 1/160 sec
(bottom 2) Canon MP-E 65mm 1-5x macro lens
ISO 100 f/13 1/250 sec