Question
A number of holes have appeared in my lawn almost as though someone has been poking a pencil in all over, and the grass has started to turn brown.
Can you possibly give me an explanation.
                Thankyou
                        Dave.  

Answer
Good Morning Dave:
From the description you have provided, I have come to the conclusion that you have Sod Webworms in your lawn.
The small holes that you are observing are probably from birds (such as starlings and Robins) pecking your lawn to get at the webworms. If you notice birds gathering on your lawn periodically that is a good sign that the webworm is there.
You need to water your lawn as soon as possible to begin control.  Water approximately one inch of water per week during the hot summer months. Set your lawnmower height to a minimum of 2 ?inches, preferably 3 inches. Mow frequently so that you cut off no more than 1/3 of the grass blades at each mowing. You need to do this to get a more dense stand of grass.

I have provided some web sites that will give much more detailed information about Sod Webworms. Copy and paste these to your browser at hit "Go"

Sod Webworm Management in Lawns: (Ohio)
http://ohioline.osu.edu/hyg-fact/2000/2011.html

Sod Weworm Control: (Colorado)
http://www.ext.colostate.edu/pubs/insect/05509.html

Sod Webworm: (Kansas)
http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/sodwebwm.htm

Have a Good Lawn!
Floyd McMahon