What's eating my greater coreopsis?

Greater Coreopsis, native to the southeastern US, is a low-maintenance perennial with few serious pests. Aphids colonise tender growth and flower buds most seasons. Leafhoppers occasionally introduce aster yellows disease, which is fatal to affected stems. Spider mites may appear in hot, dry summers. Deer and rabbits generally avoid the aromatic foliage.

Soft colonies on tips and buds; honeydew; mild distortion; rarely devastating on established plants. Hose off; treat with insecticidal soap or neem; tolerate low levels where beneficial insects are present.

Greening and distortion of flower petals; stunted, witches'-broom-like growth; no recovery possible. Promptly remove and dispose of infected plants; manage surrounding weeds; apply insecticidal soap to reduce leafhopper numbers.

Fine webbing on undersides of leaves; stippled, bronzed foliage in hot dry spells. Increase humidity with overhead watering in dry weather; apply neem oil or horticultural oil spray.