Cerura occidentalis

Cerura occidentalis, commonly known as a type of puss moth, is an insect species belonging to the family Notodontidae within the order Lepidoptera. This moth is recognized primarily for its larval stage, which can act as a defoliator of specific host plants, impacting forest health and urban ornamental landscapes.

The primary host plants for this species include trees within the family Salicaceae, with a strong preference for Salix (willow) and Populus (poplar) species. These trees serve as both food sources for the larvae and substrates for the entire developmental cycle of the moth.

The biological development follows a complete metamorphosis: egg, larva, pupa, and adult. The larvae exhibit distinctive behavioral traits, including specialized defensive structures at the posterior end of the body, which they display when threatened. This adaptation is a key characteristic used in identification by entomologists.

The economic and ecological impact of the pest is defined by larval feeding damage, which results in leaf tissue loss. Significant defoliation can reduce the photosynthetic capacity of the trees, lead to reduced annual growth rates, and potentially cause branch dieback in young or highly stressed specimens during heavy infestation years.

Effective management requires integrated pest management (IPM) strategies. Monitoring adult moth flight periods and scouting for larval activity are essential first steps. Control measures include:

• Targeted application of biological insecticides such as Bacillus thuringiensis.
• Enhancing natural biological control by protecting predator habitats.
• Applying conventional insecticides only when outbreaks threaten the survival or aesthetic value of the host trees.
• Maintaining healthy tree stands to increase vigor and resilience against pest pressure.