Hawthorn Lace Bugs – Corythuca cydoniae

Hawthorn Lace Bugs (Corythuca cydoniae) Common Name: Hawthorn Lace Bugs Latin Name: Corythuca cydoniae Appearance: Adults: The adults are delicate and lace-like, with a brown double crossbar pattern on the hemelytrons (front wings). Eggs: The eggs are 0.3 mm long, smooth, pale, glossy, semitransparent, and oval. The wide end is placed gently into the leaf. The egg’s top end is truncated and covered with brown. According to Comstock, the eggs are occasionally mistaken with specific types of fungus, such as Phoma sp., or with certain types of hemipterous galls. Nymphs: The adults are delicate and lace-like, with a brown double crossbar pattern on the hemelytrons (front wings). Host plant: This species lives in Manitoba and Saskatchewan and feeds on saskatoon. Other lace insect species may consume saskatoon or chokecherry. Territory: The hawthorn lace (Corythucha cydoniae) beetle is found over much of the continental United States, southern Canada, and northern Mexico. Damages caused by Hawthorn Lace Bugs: Lace bug-feeding leaves are stippled or mottled with several lace-winged insects present. These insects eat in vast numbers and deposit their feces on the leaves. The economic impact of these insects is not evaluated. Life history and habits: Lace bugs overwinter as adults and have two generations every year on average. Adults are little (3 mm) beetles with a lace-like coating. In early spring, the black eggs are placed in clusters on the underside of leaves and are visible. After around three weeks, nymphs emerge and feed on the undersides of the leaves. The final of the five nymphal stages (instars) is black with bright markings. The first generation of adults emerges around midsummer, and the second generation matures in the fall. These insects eat by penetrating the leaves and drawing out plant fluids using their mouthparts.