Eulecanium cerasorum

Description

Calico scale is a soft scale insect that is distinguished by its stiking black and white striped shell. Crawlers emerge in late June to early July and will feed all summer before overwintering as nymphs. Calico scale produces honeydew which covers plant material and other objects below the infected foliage. Calico scale has one generation per year.

Symptoms & Diagnosis

The adult shell is a noticable indicator of infestation. During severe infestations, branch dieback and large amounts of honeydew will rain on foliage and surrounding structures. Honeydew is colonized by sooty black mold which causes further damage by impeding photosynthesis and causing stress.

Treatment

Calico scale has proven to be difficult to treat despite being a soft scale insect. Studies have shown that the most effective time to apply treatments is during crawler emergence. Vigilant scouting is required as crawlers are most vulnerable for only one week every year.

Management

Managing tree stress is a crucial component of insect management. Tree can remain healthier and aesthetically pleasing longer by properly managing water, avoiding compaction and grade changes, and controlling insects. Fertilization improves tree vigor.

Affected Species

• Acer spp. (Maple)
• Liquidamber spp. (Sweetgum)
• Gleditisia spp. (Honey Locust)
• Zelkova spp. (Zelkova)
• Malus spp. (Crabapple)