Double Kidney

The Double Kidney moth (Ipimorpha retusa) is a member of the Noctuidae family. This moth is primarily recognized as a specialized forest pest that targets specific deciduous tree species, impacting their physiological health and aesthetic value in landscape plantings.

The primary host plants for Ipimorpha retusa include species of the genus Populus (poplars, especially aspen) and Salix (willows). It is commonly found in riparian corridors and deciduous woodland ecosystems where these trees are abundant.

The life cycle is characterized by a single generation per year. The insect overwinters in the egg stage, which is deposited on the twigs of host plants. Larvae emerge in the spring, coinciding with leaf budding. They undergo several molts before pupating, often within a folded or silken leaf structure.

Damage occurs primarily through larval feeding. The caterpillars are known to fold or roll leaves, binding them with silk, and feeding from within this protective shelter. This behavior leads to skeletonization or complete defoliation, which can stress the tree, particularly in young plantations or nurseries under drought conditions.

Integrated Pest Management (IPM) strategies for controlling Ipimorpha retusa include:

• Early detection through visual inspections of foliage during the spring to identify leaf-rolling activities.
• Application of Bacillus thuringiensis based products to control young larvae with minimal environmental impact.
• Targeted use of insecticides if infestation levels exceed economic injury thresholds in commercial forestry operations.