I have a {white} birch tree in my backyard. Recently ive noticed that the tree in infested with little 1/8 inch long bugs, the top of the tree is almost dead and they r working there way down. they are a brownish red in colour .

anyone please help..

There are several types of insects that fit your description, some harmful and so me not. They might not be related to the dieback.

I suggest that you contact a local International Society of Arboriculture (ISA) Certified Arborist to check the tree and help you diagnose the real problem. Bronze Birch Borers are a common pest, and are seldom seen since they tunnel under the bark. They often cause dieback of branches or even the death of the trees. Go to www.isa-arbor.org to find a certified arborist in your area.