Face Like A Plasterer's Radio?

The field rose attracts lots of insects. I have seen longhorn beetles there every day since the flowers opened. They used one as their marriage bed. :) A bumble bee visits regularly, I haven't been able to identify it but it's the busiest bee I have ever seen. My normal macro settings are no good as it's constantly scuttling about at speed.

Today I spotted a very tiny solitary bee on one of the flowers which turned out to be a yellow-faced bee. I might be confused but I think I read somewhere that such bees smell of lemons. I took a big sniff and nearly Hoovered it up my nose. No lemon smell. :( I can't find reference to this online so maybe I was dreaming? These bees belong to the Colletidae family and are often referred to collectively as plasterer bees due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secretions dry into a cellophane-like lining. 

I photographed what might be my first Essex skipper butterfly of the season today. Going to try again for one tomorrow to be sure. 

PS I wasn't dreaming, it was a Tweet from Ian Beavis which mentioned the lemony pheromones. :)