British Insects: Pug moths (Lepidoptera-Geometridae)
Adults. Thorax grey, with a conspicuous anterior black collar. Wingspan 18–22 mm. Forewings distinctly elongate; the outer margin convexly curved to more or less straight; the costa arched; apically blunt.
Forewings relatively conspicuously patterned; pale grey or pale greyish-ochreous, with blackish markings: two or more thin, angled striae before the middle, and two median ones which are obscure above the bend except on the costa but strong below, where they converge to the hind margin, resulting in the wing exhibiting a characteristic oblique pale median fascia; no subterminal darkening but somewhat paler than the ground colour near the apex; no noticeable pale subcostal line, but with blackish-marked veins towards the mid-termen. Forewings with a dark discal mark (but this small and somewhat disguised by association with the strong antemedian stria). The discal mark dot-like; not whitish-edged; black and distinct. Forewing fringes not chequered.
Hindwings coloured like the forewings, with blackish markings; patterned similarly to the forewings to less conspicuously patterned than the forewings; conspicuously patterned; transversely striated (especially dorsally and postmedianly); with a clear discal mark; the fringes not conspicuously chequered.
The abdomen conspicuously patterned; with an entire black sub-basal band.
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 a single sclerotized patch with a pair of apical extensions (the prongs short). The bursa copulatrix with ornamentation conspicuously restricted in distribution; coarsely, conspicuously spiny.
Early stages, ecology. Foodplants Gymnospermous; Cupressaceae. The larvae found on (Cupressus, Chamaecyparis and Juniperus; feeding on leafy shoots (mainly on young leaf tips).
Months of appearance, distribution. Adults abroad July, August, September, and October; larvae found September to December, or January to March. South-east England, Central-southern England, South-west England, English Midlands, Wales, and Ireland (having spread east and north and arrived in southern Ireland since appearing in Cornwall in 1959).
Special key characters. Forewings with a conspicuous oblique, pale dark-edged oval fascia extending from near the apex to the mid-dorsum. Hindwings pale ochreous, or pale grey.
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. http://delta-intkey.com’.