Yponomeuta cagnagella

Distinguished from other Yponomeuta species by forewing pattern: four longitudinal series of black dots with specific arrangement (first series not reaching middle, second beginning near before middle, lowest with 4–7 dots). Distinguished from Y. plumbella and Y. irrorella by specific dot configuration and association with European spindle as host. Dark grey hindwings contrast with white forewings. Larval webbing on spindle branches is characteristic.

Adults have white forewings with four longitudinal series of black dots; the first series does not reach the middle of the wing, the second begins near before the middle, and the lowest series contains 4–7 dots. Additional black dots appear before the termen. The hindwings are dark grey. The head is white, and wing cilia are white. Wingspan ranges from 19 to 26 mm. Larvae are pale greyish-yellow with black spots and a black head.

Flight period from end of June to October.

Larvae feed on European spindle (Euonymus europaeus).

• European spindle - larval food plantEuonymus europaeus; shared with Y. plumbella and Y. irrorella

Larvae produce extensive protective webbing covering branches of host plants. Pupation occurs within slightly transparent, grid-like silk cocoons consisting of a single layer of thin silk filaments (2.6–2.8 µm diameter, arranged in doublets). Cocoons have relatively low adhesive content compared to other moth species.

Adults are attracted to light, though urban populations show significantly reduced flight-to-light behavior compared to rural populations due to natural selection in light-polluted environments. Females in all populations show lower light attraction than males. During occasional outbreaks, larvae can defoliate entire trees and cover them with silk within days.

Used as model organism in studies of urban evolution and light pollution adaptation. Subject of genomic and silkomics research due to its phylogenetic position as an early diverging ditrysian lepidopteran. Larval outbreaks can cause aesthetic damage to ornamental spindle plantings through webbing and defoliation.

• Yponomeuta plumbellaShares European spindle as host plant; distinguished by different forewing dot pattern
• Yponomeuta irrorellaShares European spindle as host plant; distinguished by different forewing dot pattern

• urban evolution
• light pollution
• silk production
• pest outbreaks
• genomic model

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Urban Moths Have Evolved to Avoid the Big City Lights
• Yponomeuta-cagnagella - Entomology Today
• Genome sequence and silkomics of the spindle ermine moth, Yponomeuta cagnagella, representing the early diverging lineage of the ditrysian Lepidoptera