Peromyia trimera (Edwards, 1938) stat. rev.

Fig. 4A–B

Peromyia trimera was described by Edwards (1938) as a Joannisia and subsequently treated as a distinct species of Peromyia by Mamaev (1963), Kleesattel (1979), and Berest (1994). MJ, in his revision of Holarctic ‛Lestremiinae’ (Jaschhof 1998), regarded P. trimera as synonymous with P. ramosa (Edwards, 1938) . The problem with P. trimera is that Edwards’s (1938) description of this species was based on a single male with distorted genitalia, including collapsed gonostyli (see Jaschhof 1998). The same specimen was apparently undisturbed when Edwards (1938: fig. 25j) made the genital drawing of it. Four males of a Peromyia found in Sweden fit exactly the original description of P. trimera, causing us here to revive this species from the synonymy with P. ramosa . Male genitalic characters to distinguish the two species are as follows. In P. ramosa, the gonostyli are massive, often slightly broadened apically and covered with dense, long setae medioapically; the tegmen is blunt-ended; and the gonocoxae have a large asetose extension anteriorly (Jaschhof 1998: fig. 215ād). In P. trimera, the gonostyli are much more slender, parallel-sided, and equipped with sparse, short setae; the tegmen is pointed apically; and the asetose anterior extension of the gonocoxae is smaller (Fig. 4A). As another distinction, there are 2 rows of postocular bristles in P. ramosa but only 1 row in P. trimera . Other non-genitalic characters (see Edwards 1938) appear to be of no merit for differentiating between the two species.

Previous distribution. United Kingdom. Occurrence in Sweden: Öland, Uppland.

Specimens studied. SWEDEN: male (CEC250), Öland, Mörbylånga, Gamla Skogsby, scrubby meadow (“diversity meadow”), 18 Aug.–18 Sep. 2015, Malaise trap, M. & C. Jaschhof ; 2 males (CEC251–252), Öland, Borgholm, Rönnerum-Abbantorp NR, swampy mixed deciduous forest, 17 June–21 Aug. 2015, Malaise trap, M. & C. Jaschhof; male (CEC153), Uppland, Uppsala, Ekdalen NR, thin old oak woodland, 1̄ 15 Sep. 2003, Malaise trap, SMTP (trap 27, collection event 470).