In late summer and in spring, treat the ground around affected roses with a grub-controlling insecticide or with milky spore. Leaves become dry and have a full bronze sheen. Tiny specks may be visible on the undersides of the leaves. Eventually, thin webbing appears on the foliage. Spider mites, nearly microscopic pests that may be red, black, yellow or green.
Mites proliferate in hot, dry weather.
Knock adults off plants with a strong stream of water. Spray with a miticide three times, three days apart. Mites produce new generations in a few days, so repeat treatments will be necessary. Small circles or ovals appear in leaf margins. Leafcutter bees, which are shiny black, blue or purple bees.