Question
My weeping willow has had an infestation for last season and it has begun again this year.  There seem to be 2 types of bugs, one a dark greenish/blue beetle and also thin black bugs approx. 3-5mm long with many legs.  The leaves are being eaten almost entirely where these bugs are.  The nursey I went to last year told me to use SEVEN spray off and on but it has not helped at all.  The first beetle will only get bigger.  Any help would be greatly appreciated!!!

Answer
I would use  a spray insecticide called Orthene. Make sure you spray all the foliage. IF the tree is too large to spray use a soil applied insecticide called Bayer Advanced Tree and Shrub Insect control. Apply to the soil around the tree and the roots will carry it to the leaves and when the insects feed they are killed. The Orthene is a contact insecticide but has longer lasting effect than Sevin. Either of these will kill the beetle adults and larvae.