Euura itelmena ( Malaise, 1931 )

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 : 370-372

Euura itelmena ( Malaise, 1931)

Figures 7 , 16E–F , 21D

Pontopristia itelmena Malaise, 1931: 54 . Described: syntypes, 2♀. Published type locality: Klutchi [ Russia, Kamchatka]. Lectotype designated below.

Amauronematus itelmena: Benson 1962 ; record from Canada.

Euura itelmena: Sundukov 2017 .

Diagnosis. Female. Profile of valvulae 3 in dorsal view barrel-like ( Fig. 7F ): widened towards about the middle, then gently narrowing to the tip. In other species, the valvulae 3 widen to a point near their tip, or are subparallel. The dark fore wing costa and stigma distinguish E. itelmena from other amentorum group species, apart from E. freyja and E. pohjola n. sp.

Description. Female ( Fig. 7A–B ). Body length 3.0–4.0 mm (lectotype 4.00 mm, European specimens 3.00– 3.80 mm). Black. Pale are only more or less mandibles, fore and mid tibia, base and underside of rear tibia, extreme apices of femora, fore and mid tarsi. Cerci infuscate. Wing veins including fore wing costa and pterostigma dark [apparently faded in lectotype].

Head. In dorsal view moderately contracted behind eyes, and length posterior of eye about 0.3–0.5 × length of eye ( Fig. 7D–E ). Mostly dull with coriaceous sculpture except for labrum. Upper head densely setose; setae pale, about 0.5 × as long as anterior ocellus diameter. Clypeus truncate to slightly emarginate medially. Labrum apically rounded. Antenna 0.94–1.10 × as long as fore wing costa.

Thorax. Pronotum, mesoscutum and tegula densely punctate with small shiny interspaces; vestiture similar to upper head, adpressed. Lateral mesoscutal lobe approximately 1.5 × as long as greatest width. Mesoscutellum as broad as long, without longitudinal median furrow; finely sculptured and dull, but with only a few weak pits. Mesepisternum unsculptured, shiny, with nearly uniform covering of setae, about 0.6 × as long as diameter of anterior ocellus.

Abdomen. Valvulae 3 ( Fig. 7G ) in lateral view clearly orientated upwards; tapering to the narrowly rounded tip. In dorsal view with a barrel-like profile: widened towards about the middle, then gently narrowing to the tip; 0.9–1.1 × as wide as narrowest distal width of metatibia. Cercus reaches approximately to the tip of valvula 3. Lance: Fig. 7C . Lancet ( Fig. 16E–F ): 20–21 annular sutures, nearly straight, apex obtuse. Base of tangium with a small to minute lobe.

Male. Unknown.

Variability. The forewing stigma and costa of the lectotype and two of the older specimens (those from the 1960’s) are markedly paler than the more recent specimens, but this seems more likely to be the result of fading than to represent natural variability. Prepared on slides, the apex of the lancet of the European specimens is distinctly obtuse. Although we only examined it in situ, the lancet of the lectotype appears to be apically acute, but perhaps this is a result of an off-plane viewing angle. Otherwise, the overall form of the lancet (rather straight, approximately 20 annular sutures) of the lectotype and what can be seen of its saw serrulae resemble the European specimens.

Figures

FIGURE 7. Euura itelmena. A–B, D, F) ♀ lectotype NHRS-HEVA000006352. C) ♀ lance PR.508VV. E) ♀ PR.507VV. G) ♀ PR.519VV. Scale bars 1 mm.

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 21. Euura amentorum group.A–C E. amentorum DEI-GISHym84386 last instar larva, in ethanol:A) head and thorax. B) abdominal segments 3–5, seg. 4 dorsal annulets arrowed. C) tip of abdomen. D) E. itelmena 210010_NBH ovipositing in S. lanata catkin. E) unidentified species, larva boring in catkin axis of S. lapponum, Norway, Svanvik, 9.7.2019. F) E.? freyja larva, S. lanata, Norway, Skallelv, 16.7.2019. G) E.? freyja prepupa, S. myrsinifolia, Norway, Båtsfjord, 9.7.2021.