Euura pohjola, Liston & Vikberg & Mutanen & Nyman & Prous, 2023

Liston, Andrew, Vikberg, Veli, Mutanen, Marko, Nyman, Tommi & Prous, Marko, 2023, Palaearctic willow-catkin sawflies: a revision of the amentorum species group of Euura (Hymenoptera, Tenthredinidae), Zootaxa 5323 (3), pp. 349-395 : 379

Euura pohjola new species

Figures 11 , 12 , 16C–D , 18B

Diagnosis. The shape of the head behind the eyes distinguishes both sexes of E. pohjola n. sp. from other members of the amentorum group: in E. pohjola it is longer than, and in dorsal view not as strongly contracted as in the other species. In its dark stigma and costa E. pohjola resembles E. freyja (more slender body and valvulae 3 apically strongly expanded) and E. itelmena (lancet lower compared to its length).

Description. Female ( Figs 11A–B ). Body length 5.5–6.0 mm [holotype 5.5 mm]. Black. More or less pale are: labrum and mandibles; extreme apices of femora, undersides of tibiae, bases of tarsomeres 1; tergum 10, cerci, medial projection of hypopygium. Wing veins dark; fore wing pterostigma dark around edges, with paler central area.

Head. In dorsal view scarcely narrowed behind eyes, and length posterior of eye about 0.65–0.80 × length of eye ( Fig. 11C ). Face dull, with coriaceous sculpture on all parts except labrum ( Fig. 11D ). Densely setose; setae pale, about as long as anterior ocellus. Clypeus slightly emarginate medially. Labrum apically rounded. Antenna ( Fig. 11J ) approximately 0.75 × as long as fore wing costa.

Thorax. Pronotum, mesoscutum and tegula densely punctate with small shiny interspaces; densely setose; setae much shorter than on head, about 0.3–0.5 × as long as anterior ocellus, adpressed. Lateral mesoscutal lobe approximately 1.4 × as long as greatest width. Mesoscutellum as broad as long, with weak longitudinal median furrow; punctures slightly less dense than on mesoscutum. Mesepisternum unsculptured, shiny, with nearly uniform covering of setae, about 0.3 × as long as diameter of anterior ocellus.

Abdomen. Valvulae 3 in lateral view basally rather broad, apically truncate ( Fig. 11H ). In dorsal view nearly parallel-sided ( Fig. 11G ); distally approximately 1.5 × as wide as narrowest apical width of metatibia. Cercus reaches back approximately to tip of valvula 3. Lancet ( Fig. 16C–D ): 19 annular sutures; slightly curved; serrulae of lamnium rather flat; basal annular sutures without ctenidial teeth. Base of tangium with a moderately large lobe.

Male ( Fig. 11I ). Body length 4.0– 5.5 mm.As female, except: Abdomen black apart from pale cerci, and sternum 9 (slightly paler than other sterna). Head behind eyes in dorsal view narrower, and length posterior of eye about 0.45–0.70 × length of eye ( Fig. 12D ). Antenna 0.8–1.0 × as long as fore wing costa. Penis valve: Fig. 18B .

Variability. Female: The ovipositor is not always strongly upwardly orientated. Male: Tergal hollows and procidentia of tergum 8 highly variable ( Fig. 12A–C ). Tergal hollows vary from scarcely developed, to deep and long, and from almost completely sclerotised (black) to extensively unsclerotised (pale). Procidentia subtriangular to rectangular, and scarcely projecting beyond edge of tergum to clearly projecting.

Etymology. The species name, a noun, is that of the northern land of Pohjola, which figures prominently in the Finnish national mythological epic, the Kalevala.

Figures

FIGURE 11. Euura pohjola n. sp. A–C, E–G) ♀ holotype ZMUO.030866. D, H) ♀ paratype ZMUO.033762. I) ♁ paratype ZMUO.037228. J) ♁ paratype ZMUO.040903. K) ♁ paratype ZMUO.037229, metatarsus. Scale bars 1 mm.

FIGURE 12. Euura pohjola n. sp. A, D) ♁ paratype ZMUO.040902. B) ♁ paratype ZMUO.037229. C) ♁ paratype DEI- GISHym13882. E) ♁ paratype ZMUO.030821.

FIGURE 16. Lancets.A–B Euura freyja: A) DEI-GISHym31215. B) Pontopristia analis holotype http://id.luomus.fi/GL.9215. C–D Euura pohjola n. sp. C) holotype ZMUO.030866. D) paratype ZMUO.033762. E–F Euura itelmena E) Pontopristia itelmena lectotype NHRS-HEVA000006352. F) PR.517VV.

FIGURE 18. Penis valves. A) Euura amentorum http://id.luomus.fi/GP.110189. B) E. pohjola n. sp. paratype ZMUO.030821, valvispina (upper) and lobe on paravalva (lower) arrowed. C) E. dahlbomi http://id.luomus.fi/GP.110188. D) E. microphyes 00244_KTP. E) E. freyja, 200693_BSP. F) E. freyja ZMUO.058316.