What's eating my celosia argentea var. plumosa 'fresh look yellow'?

Celosia 'Fresh Look Yellow' (plume type) is most at risk from spider mites and aphids in summer. The feathery flower plumes are also targeted by caterpillars that hide inside them. Fungus gnats attack roots in waterlogged conditions. Early scouting of the dense plumes is essential as pests can go unnoticed.

Stippled, bronzed foliage with webbing on undersides; plumes may dry and bleach prematurely in infested plants. Neem oil or miticide spray on all leaf and stem surfaces; water consistently; avoid overhead watering.

Soft colonies on stems and at the base of plumes; honeydew causes sticky residue and black sooty mould. Insecticidal soap or neem oil spray; strong water jet; repeat treatment until colonies are eliminated.

Holes in leaves and plumes; caterpillars conceal themselves in the dense feathery flower heads. Hand-pick larvae; apply Bt (Bacillus thuringiensis) spray; check plumes weekly during summer.

Root feeding by larvae weakens plants; yellowing lower leaves and wilting despite adequate moisture. Water from the base and let the top inch of soil dry out; yellow sticky traps; Steinernema feltiae nematodes.