What's eating my catalpa speciosa?

Northern catalpa faces the same primary threat as its southern cousin: the catalpa sphinx moth caterpillar can strip the entire canopy in a season. Catalpa midge causes leaf blistering, and in the US Midwest, Japanese beetles skeletonise leaves in summer. Established trees recover from defoliation but repeated attacks cause long-term decline.

Complete or near-complete defoliation; large caterpillars in groups on leaf undersides; weakened growth and reduced flowering the following year Apply Bt kurstaki when caterpillars are small; hand-pick or knock into soapy water; conserve parasitic braconid wasps by avoiding synthetic pyrethroids

Skeletonised leaves with only the veins remaining; bronze iridescent beetles feeding in groups on foliage in July–August Hand-pick beetles in the morning when sluggish; apply kaolin clay as a deterrent; neem oil is moderately effective; avoid Japanese beetle traps near the tree

Blister-like galls and puckered, discoloured patches across the leaf surface; cosmetic rather than life-threatening Collect and bin fallen leaves in autumn; no pesticide intervention needed for established trees