Cypress lappet

The cypress lappet (Latin Pachypasa otus) is a large nocturnal moth belonging to the family Lasiocampidae within the order Lepidoptera. This species is recognized as a significant pest of various evergreen coniferous trees, capable of causing substantial damage to forests and ornamental plantings during periods of outbreak.

The primary hosts for the larvae of this species are members of the cypress family (Cupressaceae), including the Mediterranean cypress, juniper, and arborvitae (thuja). On rare occasions, the pest may be found on other coniferous species, where it consumes needles, ultimately leading to tree decline and potential mortality.

The biology of this species involves a single generation per year. Larvae overwinter in early instars, sheltering within the dense foliage of host trees. In the spring, as temperatures rise, they resume active feeding, consuming both young and mature needles voraciously. Adult flight typically occurs in the summer, followed by oviposition on the foliage or branches of host plants.

Damage symptoms include severe defoliation, which severely reduces the tree's photosynthetic capacity. When population densities are high, larvae can completely strip the crown, causing massive needle drop and overall physiological stress. This weakening makes the trees highly susceptible to secondary infestation by bark beetles and wood-boring insects.

Management strategies rely on an integrated approach:

• Regular monitoring of tree health during the spring months.
• Deployment of light traps to capture and monitor adult moths.
• Application of biological insecticides based on Bacillus thuringiensis targeting early larval stages.
• Use of systemic insecticides in severe cases during peak larval activity.

Proactive cultural practices, such as maintaining optimal tree vigor and cleaning up debris, are also essential for long-term population suppression and prevention of severe outbreaks in sensitive landscape areas.