Little Beasty Help!

Hi Everyone
This is my first post and already I want help! So with the warmer weather I have started doing some work on both my front and back garden eg laying turf, planting flower seeds and spring onions etc. I noticed yesterday millions (well quite a few at least) of flying beetle thingies - without wanting to sound too scientific :WINK1:. They were about the same size (perhaps a little smaller) than a normal house fly and seemed most interested in long grass. They also didn't like keeping still but (eventually) I managed to get a pic of one - see attached.

Just for info I live in Nottingham and it was a hot and sunny day.

Sooo my questions are:

1. What the heck are they?!

2. Are they harmless (or even helpful) or after all my hard work in the garden do they require 'putting to sleep'?!

in anticipation.

Jase.

 

http://www.nemasysinfo.com/chafers.shtml
Not good........

 

Arrrrrrrrhhhhhhhhhhhhhhhh!! *Looks outside to see hundreds of the things swarming around*!! My lovely new lawn! That's the feller. Exterminate!!! Having said that it seems as if there are chemicals available to kill the grubs but not the actual beetles?!

If possible I would kinda like to pre-empt them laying the grubs in the first place! Any ideas anyone?
Ty very much for the info Catztail

 

According to this, not all chafer beetles, or their grubs are necessarily enemies:

http://maria.fremlin.de/stagbeetles/larva-guide/index.html