Question
This year, for the first time, we have noticed that all of the wild rose bushes in the area are laden with what looks like a large brown fur ball.  Is this a fungus?  If so, what causes it and what should we do?

Answer
The "fur ball" is called Robins Pincushion and is caused by a mother wasp laying her eggs on an area of the rose bush. Here is a picture of a pin cushion. The wasps are the good guys of the garden but if you don't like the look of the ball, just cut it off and put it somewhere else in the garden as the little wasps eat many of the nasty insects in the garden.
http://homepage.ntlworld.com/ray.hamblett1/nature/rosa.html