70.192 Aplocera plagiata (Treble-bar) 1867
fw: 19-22mm; bivoltine in south May-Jun, Aug-Sep, univoltine in north Jul-Aug; Hypericum spp (St John’s worts); common throughout GB.
ID: ssp plagiata present throughout has grey ground colour, ssp scotica present in north has blue-grey ground colour. Very similar to A.efformata (Lesser Treble-bar), which is smaller (fw 16-19mm). Males are best distinguished by examination of the abdominal apex, which is pointed in A.plagiata due to its long straight valvae (visible ventrally in live specimens) and blunt in in A.efformata due to its valvae being short and bent medially. Basal cross-band is angled >=90deg in A.plagiata, <=90deg in A.efformata; cross-bands generally less intense in A.efformata. Females may need genital dissection for confident identification of individuals with fw around 19mm. A.praeformata (Purple Treble-bar) is an extremely rare migrant with only 2 British records; it averages larger (fw 20-25mm); it has a short brown bar distal to the central portion of the median cross-band and its basal cross-bar has an acute angulation.
Page published 01/03/2014 (needs labelling)