Aprionus borri, Jaschhof & Jaschhof, 2017

Jaschhof, Mathias & Jaschhof, Catrin, 2017, New species of Aprionus (Diptera, Cecidomyiidae, Micromyinae) from Sweden and other parts of the Palearctic region, European Journal of Taxonomy 378, pp. 1-38 : 33-35

Aprionus borri sp. nov.

urn:lsid:zoobank.org:act:F17CA9EB-9D1F-47A1-9861-FC7054FAA837

Fig. 19

Diagnosis

Among Aprionus with toothed gonostyli, Aprionus borri sp. nov. is the only species whose tegminal fingers are reduced to a single pair that forms the lateral and apical margins of the tegmen (↓, Fig. 19A ).

Etymology

Borr, husband of Bestla, is Odin’s father.

Material examined

Holotype

SWEDEN: ♂, Öland, Mörbylånga, Gamla Skogsby, 56.61° N, 16.51° E, mixed broadleaf forest, Malaise trap, M. and C. Jaschhof leg., 27 Jun.–30 Jul. 2014 ( NHRS, no. CEC159 ).

Paratypes

SWEDEN (4 paratypes in NHRS, 5 in DEI): 1 ♂, same data as the holotype (no. CEC 160); 1 ♂, same data, but 9 Jun.–14 Jul. 2015 (no. CEC 308); 1 ♂, same data, but 15 Jul.–17 Aug. 2015 (no. CEC 167); 1 ♂, Öland, Mörbylånga, Stora Dalby forest NR, 56.47° N, 16.45° E, mixed broadleaf forest with much dead ash, MT, MCJ leg., 9 Jul.–8 Aug. 2015 (no. CEC 163); 2 ♂♂, Öland, Mörbylånga, Västerstad elmforest NR, 56.42° N, 16.42° E, mature elm forest, MT, MCJ leg. with the SMTP (trap 3002, collecting event 3055), 10 Jul.–5 Aug. 2014 (nos CEC 161– CEC 162); 1 ♂, Öland, Borgholm, Lindreservat NR, 57.31° N, 17.04° E, mixed deciduous forest, MT, MCJ leg., 11 Jun.–21 Jul. 2015 (no. CEC 307); 1 ♂, Öland Borgholm, Horns kungsgård NR, 57.20° N, 16.93° E, mixed forest of birch, alder and willow trees at lakeside, MT, MCJ leg., 21 Jul.–22 Aug. 2015 (no. CEC 168); 1 ♂, Öland, Borgholm, Skepparsäng NR, 57.31° N, 17.04° E, mixed coniferous/ broadleaf forest, MT, MCJ leg., 11 Jun.–21 Jul. 2015 (no. CEC 166).

Differential diagnosis

At a cursory glance, the tegmen of Aprionus borri sp. nov. seems to lack finger-like processes, especially in those slide-mounts where the finger apices intersect and then appear like they would form a closed, rounded margin apically. Aprionus with apically entire, fingerless tegmina (and toothed gonostyli) are A. ferulae Mamaev, 1998 , a little-known species from Turkmenistan; A. reduncus Jaschhof, 2009 , a species rarely collected in Fennoscandia; and A. umbrellus Mamaev & Berest, 1990 , found once in Ukraine. The presence of a single, marginalized pair of tegminal fingers is not only a character to distinguish A. borri sp. nov. from these other species; more interesting is our observation that exactly the same type of tegmen (in combination with toothed gonostyli) occurs in several unnamed species in our collection from Japan, Malaysia, and South Africa. All these species are so similar to each other, also in other respects, that one can hardly question their close interrelationship. It appears that A. borri sp. nov. is an (or the) European representative of a species group, potentially the borri group, with a wide distribution in the Old World. (For the sake of completeness it is mentioned here that there are also Aprionus , in which the presence of an apically entire, fingerless tegmen is combined with untoothed gonostyli, namely A. carpathicus Mamaev & Berest, 1992 ( Ukraine) , A. dispar Mamaev, 1963 (widespread Europe), and A. pseudispar Jaschhof, 1997 ( Sweden, Germany).)

Other characters

Body size 1.0 mm.

HEAD. Postfrons setose. Eye bridge 1–2 ommatidia long dorsally. A dense row of 8–10 postocular bristles. Flagellomeres usually 12, in one of the specimens studied 11 due to fusion of the two apical flagellomeres. Fourth flagellomere with neck much shorter than node, 1 complete and 2 incomplete crenulate whorls, simply hair-shaped translucent sensilla ( Fig. 19B ). Presence of translucent sensilla confined to 5 proximal flagellomeres. Palpus short, 3-segmented, basal segment slightly swollen, apical segment pointed, longest of all.

WING. ApicR 1 1.5–2.0 times as long as Rs.

LEGS. Claws subrectangular, toothless. Empodia rudimentary.

TERMINALIA ( Fig. 19A ). Ninth tergite much shorter medially than laterally, anterior margin not sclerotized. Gonocoxites: ventral bridge fully membranous, indistinct; dorsal apodemes short, ending well before ventroanterior gonocoxal margin, dorsal bridge broadly rounded. Gonostylus slender, evenly tapered to tip; apical tooth large, its size relative to gonostylar body varying, appears sharply pointed in lateral view but is actually flattened and rounded apically; 0–1 bristles subapicomedially. Tegmen twice as long as wide, widest on apical third portion; dorsal wall weakly sclerotized, apparently with slit-like lengthwise opening. Subanal plate without clear contours, recognizable by irregular dark markings (‘folds’) dorsally of tegmen.

Distribution and phenology

Sweden (Öland). Specimens of Aprionus borri sp. nov. were collected from June to August in various broadleaf forests on the island of Öland.

Figures

Fig. 19. Aprionus borri sp. nov., holotype, ♂. A. Genitalia, ventral. B. Fourth flagellomere, lateral. Scale lines: 0.05 mm. The arrow indicates an important diagnostic character.