Stackelbergiella sikorai sp. nov.

Figs 16–17

Diagnosis. This is a typical Stackelbergiella (Jaschhof & Jaschhof 2013: 355f.), distinguished from both S. hordei and S. rickebasta in that the gonocoxal synsclerite has a small, U-shaped emargination ventrally, which is flanked by inconspicuous, microtrichose protrusions (Fig. 16, ↓ 1). As another distinction, the base of the aedeagal apodeme is just slightly thickened, not T-shaped (Fig. 17, ↓ 2). Females and preimaginal stages of the new species are unknown.

Other male characters. Body size 1.2 mm. Head. Flagellomeres 15. Neck of fourth flagellomere 0.8 times the length of node. Palpus short, 2 setose segments; basal segment globular, half as long as napiform apical segment. Wing slightly longer than body, 2.8 times longer than wide. Legs. Claws thin, sickle-shaped, with single large tooth basally. Genitalia. Gonocoxae with sparse setae ventrally; pointed ventroposteriorly; with faint, dark pigmentation around the emargination (Fig. 16). Gonostylus twice as long as broad, slightly bent, pointed apically; no apical spine (Fig. 16). Aedeagus including apodeme almost as long as gonocoxae; apex truncate or slightly concave (Fig. 17). A single pair of long, sclerotized parameres whose pointed apices are bent ventrally (Fig. 17).

Etymology. This new species is named after Tomáš Sikora, Ostrava (Czech Republic), who in recent years exhibited his talents as a successful collector and careful student of mycophagous Cecidomyiidae, with a special focus on the fauna of the Czech and Slovak Republics. The Estonian specimen studied here of S. sikorai was detected by Tomáš and correctly identified as a new Stackelbergiella .

Type material. Holotype. Male, Sweden, Öland, Borgholm, Horns kungsgård Nature Reserve, swampy, mixed broadleaf forest at lakeside, 21 July–22 August 2015, Malaise trap, M. & C. Jaschhof (spn. no. CEC 1614 in NHRS).

Other material studied. Estonia: 1 male, Pärnumaa, Jõesuu, 58°25´52´´N / 25°02´39´´E, 15–25 August 2011, EMTP & A. Martsoo (in IZBE) .