Plant lice

Since I scattered the chicken dung instead self made compost, I see lots of plant lice on the garland chrysanthemum. It is said that the veteran farmers prefer the compost made from grass not from animal dung. Nitrogen included in animal dung effects quickly so that the plants grow quickly, on the other hands the surplus nitrogen on the growing point attracts the insects like plant lice. Once the plant lice come, it is not easy to wipe them all.
What Should I do?