Hi guys, Im new here and also VERY new to gardening!!

Ive recently moved into my first home and am currently trying to sort out the garden so we can enjoy this lovely weather properly!!

Anyway, firstly, please take a look at the attached photographs I took of the conifers. As you can see, they are very patchy with browny grey dead sections, tiny bugs to appear to fly out of these areas when 'trimming' the connifers to!?

Im sure I am in the right place to find out what the problem is, and if it is possible to overcome this?

Any advice would be much appreciated!