Dianous coerulescens (Gyllenhal, 1810), 2023

Ferreira, Raul Nascimento, 2023, Dianous coerulescens (Gyllenhal, 1810), a new species for Portugal (Coleoptera: Staphylinidae: Steninae), Arquivos Entomolóxicos 26, pp. 9-10 : 10

Dianous coerulescens (Gyllenhal, 1810)

PORTUGAL: Beira Alta, Viseu, Lamego, Sande, on the bank of a brook between moss and vegetation, June 2, 1962, 1 ex., R. N. Ferreira leg. and coll. ( RNFC).

Body length: 6-8 mm long. Body shiny metallic blue to greenish-blue, with upper surface moderately to strongly and densely punctured. The head is transverse, with prominent convex eyes and long tapering temples. Antennae and palps dark, with the first long and weakly clubbed. Pronotum elongate, broadest in front of the middle and constricted in front of the base. Elytra square to slightly elongate, much broader than the pronotum and with prominent shoulders, weakly rounded and each with an orange spot behind the middle. Tergites 1-4 with paratergites, without basal ridges and finely punctured and tergites 5 and 6 with moderate paratergites. Last segment with a pair of long stout setae (absent in Stenus ). The legs are long and slender, entirely dark although the tibiae may be lighter towards the apex. Hind tarsi long with the first and fifth segments longer than the others and the fourth weakly bilobed. Distinguished from all Portuguese Stenus by the paired abdominal setae, the metallic coloration and the long, tapering temples.