Last week as our lilac bushes were beginning to bud, my husband and I noticed some teeny tiny insects all over the newly budding leaves. I've watched them over the course of the week. Their numbers seemed to have gone down dramatically since the leaves have been growing larger, but there are still a few insects here and there. I have no idea what they could be and was wondering if it might be a harmful pest. I understand that lilacs generally don't have too many pest problems. I took a macro shot this morning and kindly ask if anyone here might know what it is. I live in Northern Wisconsin, Zone 3. Thanks in advance for any advice! I estimate the size of each bug to be about 1-2 mm long.