Aprionus aberrantis Mamaev, 1998

Jaschhof, Mathias & Jaschhof, Catrin, 2017, Mycophagous gall midges (Diptera, Cecidomyiidae: Lestremiinae, Micromyinae, Winnertziinae, Porricondylinae): first records in Sweden and descriptions of closely related new species from elsewhere, Zootaxa 4226 (4), pp. 546-570 : 548-549

Aprionus aberrantis Mamaev, 1998

Fig. 1A ̄B

Mamaev (1998) described Aprionus aberrantis from a single male collected in southwest Russia in 1967. His description lacks illustrations, making the species difficult to identify, except that the antennae were mentioned to have 17 flagellomeres, not 12 as is typical in Aprionus and other Micromyinae . MJ, who studied the holotype of A. aberrantis in 2006, realized that three specimens in the Jaschhof collection belong to this species: a male collected not far from the type locality and two males collected in Germany, all too poorly preserved for description. Here we report on the occurrence of A. aberrantis in southern Sweden, the northernmost distribution of this species. Based on the Swedish specimens, Mamaev’s (1998) male description is supplemented here, as follows. The postfrons is setose; 6̄7 postocular bristles form a single sparse row; flagellomeres ( Fig. 1B ), which number 15 to 17, have necks and nodes of equal length, sensory hairs arranged in 1 complete and 2̄3 incomplete whorls, with the crenulation somewhat degenerated, and both simple and two-branched hair-shaped translucent sensilla; the palpus may consist of 3 or 4 segments; R1 is up to 3 times longer than Rs; claws are bent at right angles, with 2 fine teeth at the bend; empodia are vestigial; the ninth tergite has a weak, deeply concave anterior margin; the short gonocoxae have a wide ventral emargination and a wide, broadly rounded dorsal bridge; the elongate gonostylus is slightly flattened, tapered towards the apex, and equipped with an inconspicuous tooth of fingernail-shape; the tegmen, which is membranous rather than sclerotized (and thus easily distorted in slide-mounts), bears 8̄9 pairs of short finger-like processes, the latter tending to point towards the head end; the subanal plate is membranous (its outline thus variable), with a pale, irregular scale-pattern; and the cerci are covered with conspicuously large microtrichia (see Fig. 1A for genitalic characters). The number of flagellomeres in combination with the tegmen structure make A. aberrantis unmistakable. This unusual Aprionus is tentatively classified here in the Aprionus spiniger ( Kieffer, 1894) group (see Jaschhof 1998, Jaschhof & Jaschhof 2009).

Previous distribution. Russia (Near East). Occurrence in Sweden: Skåne, Öland.

Specimens studied. SWEDEN: male (CEC156), Skåne, Simrishamn, Stenshuvud NP, alder swamp forest, 26 May ̄ 28 June 2010, Malaise trap, M. & C. Jaschhof; male (CEC157), Öland, Mörbylånga, Gamla Skogsby, mixed deciduous forest , 8 Aug. 2014, aspirator, M. Jaschhof; 5 males (CEC210–213, 261), same locality , 13 May–14 July 2015, Malaise trap, M. & C. Jaschhof; male (CEC158), Mörbylånga, Västerstad elmforest NR, mature elm forest, 10 July ̄ 5 Aug. 2014, Malaise trap, SMTP (trap 3002, collecting event 3055); male (CEC214), Mörbylånga, Stora Dalby forest NR, mixed deciduous forest with much dead ash , 9 July–8 Aug. 2015, Malaise trap, M. & C. Jaschhof. New to GERMANY: male (A7630), Mecklenburg-Vorpommern, Rügen, Lohme, old-growth mixed forest of beech, pine and larch , 4 Sep. 1994, sweepnet, M. Jaschhof; male (A7631), Mecklenburg-Vorpommern, Gützkow, swamp forest of alder and ash , 27 May 1995 aspirator, M. Jaschhof (both in SDEI). RUSSIA: male (A7629), Caucasus Mountains, Gornaya Legenda N Guzeripl’, Belaya valley , mixed forest , 26 July and 4 Aug. 1994, sweepnet, W. Mohrig (in SDEI).

Figures

FIGURE 1 A – B. Aprionus aberrantis, male (specimen from Sweden). A: Genitalia, ventral. B: Fourth flagellomere, lateral. Scales for A – B, 0.05 mm.