Pandemis pyrusana

Distinguished from similar leafroller moths by forewing size and pattern, geographic range, and host associations. Males identified by presence of costal fold. Genitalia examination may be required for definitive separation from congeners. Distinguished from sympatric Choristoneura rosaceana by species-specific pheromone blend composition and courtship behavior.

Forewings 8–12.5 mm in males, 9.5–14 mm in females. Adults have mottled brown forewings with variable darker markings. Wing pattern includes a distinct costal fold in males. Resting posture characteristic of Tortricidae, with wings held roof-like over body.

Forests with deciduous trees and shrubs. Found in riparian corridors, orchards, and wooded areas where host plants occur.

Western North America: Alberta and British Columbia south through Idaho, Utah, Colorado, and California. Also present in Washington State apple-growing regions.

Adults active May to July, with second generation September to November in coastal California. One or two generations per year depending on latitude and elevation.

Larvae feed on leaves of deciduous woody plants, rolling and tying leaves together to form shelters.

• Alnus - larval food plantmultiple species
• Betula occidentalis - larval food plant
• Lonicera - larval food plantmultiple species
• Cornus sericea - larval food plant
• Ribes - larval food plantmultiple species
• Ceanothus cuneatus - larval food plant
• Malus - larval food plantincluding Malus pumila (apple)
• Prunus - larval food plantincluding Prunus avium and Prunus virginiana
• Pyrus - larval food plantmultiple species
• Rosa - larval food plantmultiple species
• Populus tremuloides - larval food plant
• Salix - larval food plantincluding Salix lasiolepis and Salix sessilifolia

Complete metamorphosis with egg, larva, pupa, and adult stages. One or two generations per year. Overwintering stage not specified in available sources.

Larvae are leafrollers, constructing shelters by rolling and tying leaves with silk. Males initiate courtship by approaching females, with stereotyped sequence including wing fanning and antennal contact. Pheromone-mediated communication guides mate location. Males show reduced source contact and attraction when exposed to specific pheromone inhibitor blends, possibly functioning in reproductive isolation from sympatric species.

Herbivore on deciduous woody plants. Larval feeding damage can defoliate host plants. Susceptible to granulovirus (PapyGV) infection, which increases mortality and alters feeding behavior.

Pest of apple (Malus pumila), pear, cherry (Prunus avium), and other deciduous fruit crops. Leaf rolling and feeding damage reduce fruit quality and tree vigor. Target of pheromone-based monitoring and mating disruption in integrated pest management programs. Pheromone inhibitor research has been conducted to improve species-specific control.

• Choristoneura rosaceanaSympatric and synchronic leafroller pest in Washington apple orchards; distinguished by different pheromone blend composition and species-specific courtship behaviors including distinct male wing fanning patterns.
• Other Pandemis speciesCongeners may overlap in range; identification requires examination of genitalia or pheromone analysis.

• leafroller
• pest
• tortricid
• fruit pest
• western North America
• pheromone
• biological control

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Short communication. Pheromone inhibitors for Pandemis pyrusana males (Lepidoptera: Tortricidae)
• The effect of the granulovirus (PapyGV) on larval mortality and feeding behaviour of the Pandemis leafroller,Pandemis pyrusana(Lepidoptera: Tortricidae)
• Courtship Behavior in <I>Choristoneura rosaceana</I> and <I>Pandemis pyrusana</I> (Lepidoptera: Tortricidae)