My 2 lilac trees that are near one another(1white and 1 purple)Have a brown bug the size of a small fly,looks like maybe hard shell,flys and i believe has antennas on them and the new tip growth and the new flower clusters have all the life taken from them and are now dead and black.The other lilac tree that i hardly ever fertilize is doing o.k. but it is quite a distance from them.Any help would be greatly appreciated,thanks in advance,Leona.