British Insects: Pug moths (Lepidoptera-Geometridae)


L. Watson and M. J. Dallwitz

Pasiphila debiliata (Hübner)

Bilberry Pug.

Adults. Posterior tibiae of males 4-spurred. Wingspan 19–23 mm. Forewings not noticeably elongate; the outer margin convexly curved; the costa more or less straight to arched; apically blunt.

Forewings relatively conspicuously patterned; usually very pale tinged green or whitish-greenish when fresh, but soon fading to whitish-greyish; conspicuously striated fuscous-grey, the striations darkened on the costa; edges of the median band blackish-dotted, its anterior curved and its posterior twice-angulated (dentate) towards the costa; the subterminal line obscure to not apparent. Forewings with a dark discal mark. The discal mark dot-like; not whitish-edged; black and distinct. Forewing fringes conspicuously chequered to somewhat chequered.

Hindwings green, greenish or pale grey; patterned similarly to the forewings; conspicuously patterned (striations and fasciae matching those of the forewings, including the dotted angulate postmedian line); conspicuously transversely striated (the several dark striae sharp and wavy, the postmedian fascia and dotted line angulated); without a clear discal mark (this at best obscure); the fringes not conspicuously chequered (only obscurely so).

The abdomen conspicuously patterned; with an entire black sub-basal band (this broad).

Neuration. Vein 10 of the forewings arising out of 11 and anastomosing with 9 to form a simple areole.

Genitalia. The male abdominal plate in the form of two separate sclerotized components (these apically crossed). The bursa copulatrix entirely smooth or only very finely scobinate (smooth or in parts very finely scobinate).

Early stages, ecology. Botanically specialised. Foodplants woody-dicotyledonous; Ericaceae. The larvae found on Vaccinium myrtillus; feeding on flowers.

Months of appearance, distribution. Adults abroad June, July, and August; larvae found April and May. South-east England, Central-southern England, South-west England, English Midlands, Northern England, Southern Scotland, Northern Scotland, Wales, and Ireland (locally common south of Staffordshire to west Sussex, including Wales, found only sporadically elsewhere).

Special key characters. Forewings green or greenish when fresh. The postmedian forewing line twice-angulated (dentate) near the costa. Hindwings greenish when fresh, or predominantly black, or not predominantly green, yellow, or black; green, or greenish, or pale grey.

Illustrations. • P. debiliata (Bilberry Pug) and Chloroclystis v-ata, with larvae: Barrett. • P. rectangulata and P. debiliata, with Anticollix, Chloroclystis and Gymnoscelis: Hubner 1809–1817. • P. debiliata (Bilberry Pug), with P. rectangulata and Chloroclystis v-ata: South. • P. debiliata (Bilberry Pug) and P. rectangulata (Green Pug), with Chloroclystis v-ata.

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: Pug moths (Lepidoptera-Geometridae). Version: 29th December 2011.’.