Morrill lace bug

The Morrill lace bug (Corythucha morrilli) is a member of the Tingidae family, belonging to the order Hemiptera. These insects are easily recognized by the intricate, lace-like appearance of their pronotum and hemelytra. They are piercing-sucking pests that primarily target the foliage of various host plants, causing significant cosmetic and physiological damage over time.

This species has a specific preference for plants within the Asteraceae family. It is frequently observed on various species of sagebrush (Artemisia), ragweed, and other related ornamental or wild plants. Due to its feeding habits, it can thrive in both natural habitats and managed landscapes, often becoming a nuisance in home gardens and nursery production facilities.

The life cycle of Corythucha morrilli consists of egg, nymph, and adult stages. Females typically deposit their eggs in small clusters on the undersides of leaves, often covering them with fecal material for protection. Nymphs remain gregarious during their early stages, feeding in colonies. Depending on the climate, the species may complete several generations per year, with adults typically overwintering in plant debris or bark crevices.

Feeding damage is characterized by chlorotic stippling, where the leaves become speckled with small white or yellow spots. As the infestation progresses, these spots coalesce, leading to severe yellowing, curling, and early leaf drop. Beyond the direct loss of plant vigor, the presence of black frass spots on the leaf underside further degrades the health and appearance of the plant, hindering photosynthesis.

Integrated Pest Management (IPM) is the most effective approach to handling Corythucha morrilli. Key tactics include:

• Regular inspection of the foliage, especially the undersides of leaves.
• Removal of heavily infested plant material during the early stages of an outbreak.
• Implementation of botanical or synthetic insecticides labeled for lace bug control.
• Cultural practices like proper irrigation to reduce plant stress.