Figure of Eighty

The Figure of Eighty (Tethea ocularis) is a moth species belonging to the family Drepanidae. Known as a pest in forestry and ornamental arboriculture, its common name is derived from the distinctive markings on its forewings that resemble the number 80. It represents a recurring challenge for maintainers of specific deciduous plantations.

This species primarily feeds on various poplar species (genus Populus), including aspen. It is commonly found in temperate forest zones where host availability is high. While generally not considered a severe economic pest, outbreaks in nurseries can cause significant damage to the foliage of young saplings and ornamental trees.

The life cycle involves a single or double generation per year. The insect overwinters as a pupa protected within a cocoon, often located in bark crevices or among leaf litter on the ground. Adult moths emerge in late spring or early summer, and the subsequent larval stage feeds during the warmer months, causing the primary damage to the host plant.

The damage caused by the larvae is characterized by defoliation. As the larvae feed, they consume the leaf tissue, which reduces the tree's photosynthetic capacity. Severe infestations can weaken the trees, making them more susceptible to secondary stressors, such as drought, viral infections, or secondary pest colonization.

Effective management strategies focus on monitoring and early intervention. The following measures are generally recommended:

• Regular inspection of poplar stands during the larval feeding season.
• Application of bio-rational pesticides, such as Bacillus thuringiensis, which target larvae without harming beneficial pollinators.
• Maintenance of plant health through proper irrigation and soil management to increase tree resistance to pest pressure.