Anacampsis populella

Reliable separation from the similar Anacampsis blattariella requires genitalia dissection; external morphology is insufficient due to high variability in both species. Larvae distinguished by greyish-green or yellowish body with round black pinacula, black head, and divided black prothoracic plate; anal plate brownish. Leaf-rolling behavior on host plants provides a field clue.

Small moth with wingspan 14–19 mm. Forewings whitish, variably sprinkled with black or dark grey, often palest toward base of costa; costal edge sometimes yellowish-tinged. Variable patterning includes occasional large black patch on dorsal two-thirds from base to near tornus; stigmata blackish, often concealed; whitish obtusely angulated fascia at three-quarters, indented above angle, sometimes indistinct; terminal black dots present. Hindwings over 1, rather dark grey. Abdomen with segments 2–4 often ochreous-yellow. Sexes similar in appearance.

Found in stands of poplar and willow, including forest plantations, moorlands with birch, and coastal dunes with creeping willow. Adults occur on tree trunks, in foliage, and come to light.

Native to Europe, with records across most of the continent including Sweden (type locality), Germany, Czech Republic, Belgium, and the United Kingdom. Accidentally introduced to North America.

Adults on wing from May to September depending on location; peak activity June to August. Larvae present from mid-April to June. Eggs overwinter.

Larvae feed on leaves of poplars (Populus species) and willows (Salix species). Specific hosts include Populus tremula, Salix caprea, Salix alba, and Salix repens.

• Populus tremula - larval foodplantprimary host in some populations
• Populus sp. - larval foodplantgeneral poplar feeder
• Salix caprea - larval foodplantgoat willow
• Salix alba - larval foodplantwhite willow
• Salix repens - larval foodplantcreeping willow, coastal dunes

Univoltine. Eggs laid at base of buds in clusters, overwintering through winter. Larvae emerge in spring, develop through three instars from April to June. First instar feeds freely on leaf underside; after first molt, larvae roll leaves with silk into tubes and feed inside. Pupation occurs within the rolled leaf in a cocoon. Adults emerge from May to September.

Larvae construct leaf rolls by rolling leaves toward the abaxial (lower) surface, securing edges with silk strands. Most rolls contain a single leaf, though 20% incorporate 2–5 leaves. On creeping willow, small leaves require several to be spun around the central shoot. Adults are nocturnal and attracted to light.

Herbivore on poplar and willow foliage. Prey for diverse natural enemies including parasitic Hymenoptera (at least 20 species recorded, with parasitism rates up to 59%), insect predators, and birds; natural enemies cause 63–88% mortality of larval and pupal populations.

Minor pest of Populus tremula in forestry plantations, causing measurable leaf damage. Used as a study organism for leaf-roller biology and parasitoid community ecology.

• Anacampsis blattariellaExternally variable and indistinguishable without genitalia dissection; both species share similar size range and color variability.
• Anacampsis temerellaLarvae also roll leaves of Salix repens on coastal dunes; larvae distinguished by morphological details, though both use similar host and habitat.

• leaf-roller
• univoltine
• poplar pest
• parasitoid host
• variable morphology
• genitalia identification required

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• The biology of Anacampsis populella (Clerck) (Lepidoptera, Gelechiidae)
• Zur Morphologie, Biologie und Ökologie von Anacampsis populella (Clerck) (Lep., Gelechiidae) Contributions to the morphology, bionomy and ecology of Anacampsis populella (Clerck) (Lep., Gelechiidae)
• The status and distribution of the nationally rare micro-moth Anacampsis temerella (Lienig and Zeller, 1846) (Lepidoptera: Gelechiidae) in Lancashire in 2021, with observations on other Salix repens L. – feeding Lepidoptera