Euura sylvestris (Cameron, 1884)

Prous, Marko, Liston, Andrew & Mutanen, Marko, 2021, Revision of the West Palaearctic Euura bergmanni and oligospila groups (Hymenoptera, Tenthredinidae), Journal of Hymenoptera Research 84, pp. 187-269 : 187

Euura sylvestris (Cameron, 1884)

Figs 5P, S , 9D , 10K , 11F, G , 19 , 25

Nematus sylvestris Cameron, 1884: 266. Type locality: not stated in original description (ST); according to Cameron (1885) "Cadder Wilderness" [Scotland, Glasgow area]. Lindqvist (1962) described the results of his studies of the original description, and by R. B. Benson of the “type”, and reinstated the name as valid.

Pteronidea straminea Lindqvist, 1958: 103. Type locality: Nurmes, Finland (HT). Syn. nov.

Pteronidea angustiserra Lindqvist, 1969: 241-242. Type locality: Mustasaari, Finland (HT). Syn. nov.

Pteronidea disparoides Lindqvist, 1969: 245. Type locality: Espoo, Finland (HT). Syn. nov.

Similar species.

Females are most similar to Euura oligospila group, E. respondens , and E. bergmanni , from which it differs usually by having a longer malar space. Lancet is usually narrower compared to E. bergmanni . Clypeus is usually less deeply emarginate compared to Euura oligospila group. Ventral part of 2nd to 4th suture of lancet is weakly or distinclty curved basally in E. sylvestris , but oblique and more or less straight or weakly curved apically in E. respondens . Males distinguishable from other species by their relatively distinct penis valves.

Genetic data.

COI. Based on 22 specimens, maximum within species distance is 3.68% (5.68% when including also Nearctic-only BINs) and the nearest neighbour, diverging by a minimum of 5.45%, is Euura viridis subgroup. BINs: BOLD:AAG3515 (Holarctic), BOLD:AEH2646 (ZMUO.038944, Finland), and possibly also Nearctic BOLD:AAU8841, BOLD:ACJ5634, BOLD:ACI4984, BOLD:AAG3521, BOLD:ACN0565.

Nuclear. Based on 14 specimens, maximum within species distance is 0.97% (0.83% based on haplotypes of individual females). The nearest neighbour, diverging by a minimum of 2.72%, is Euura viridis .

Host plants and behaviour.

Hosts: Salix spp. and at least occasionally Populus tremula . Cameron (1884) included a description of the larva of N. sylvestris in the species’ description, and gave the host as Salix caprea . Other Salix species recorded as hosts are: Salix pentandra , Salix phylicifolia ( Kangas 1985), and Salix myrsinifolia ( Kontuniemi 1971). We have collected or reared larvae from S. caprea , S. pentandra , S. hegetschweileri , S. myrsinifolia , and Populus tremula . Apparently there can be more than one generation per year ( Kontuniemi 1971).

Distribution.

Holarctic ( Sundukov 2017, current data). Specimens studied are from Austria, Finland, Lithuania, and Sweden.

Type material.

Pteronidea straminea Lindqvist, 1958. HT, ♀, http://id.luomus.fi/GL.3512 (saw slide PR240.AZ lost?), MZH. Lindqvist (1972) synonymised Pteronidea straminea with Pteronus pallens Konow, 1903 (see Euura pallens ). Unfortunately, the saw of the holotype of Pteronidea straminea seems to be lost, but judging from the figure by Lindqvist (1958: 101, Fig. 15 ) the serrulae do not appear to be as prominent as in E. pallens (Fig. 7B ) and seem to fit better with E. sylvestris , although synonymy with E. respondens cannot be excluded.

Pteronidea angustiserra Lindqvist, 1969. HT, ♀, http://id.luomus.fi/GL.3443, MZH.

Pteronidea disparoides Lindqvist, 1969. HT, ♀, http://id.luomus.fi/GL.3493, MZH.

Figures

Fig ure 5. Characters of Euura hypoxantha, Euura bergmanni and Euura oligospila groups, females A Euura oligospila DEI-GISHym 84738 B Euura leptocephalus ZMUO. 033448 C Euura lienterica DEI-GISHym 21362 D Euura reticulata ZMUO. 033533 E Euura hypoxantha ZMUO. 035686 F Euura brevivalvis DEI-GISHym 31135 G Euura viridis ZMUO. 035636 H Euura frenalis ZMUO. 035931 I Euura leptocephalus ZMUO. 033448 J Euura brevivalvis DEI-GISHym 84214 K Euura brevivalvis DEI-GISHym 84214 L Euura oligospila ZMUO. 040699 M Euura bergmanni ZMUO. 033423 N Euura bergmanni ZMUO. 040825 O Euura viridis ZMUO. 035636 P Euura sylvestris ZMUO. 038944 Q Euura respondens http: // coll. mfn-berlin. de / u / 111027 R Euura bergmanni DEI-GISHym 31138 S Euura sylvestris DEI-GISHym 21351 T Euura oligospila DEI-GISHym 88899.

Figure 7. Lancets of Euura. A Euura reticulata PR. 588 VV B Euura pallens lectotype GBIF-GISHym 3863.

Figure 9. Lancets of Euura oligospila and Euura bergmanni groups. A Euura frenalis DEI-GISHym 31132 B Euura oligospila DEI-GISHym 88899 C Euura respondens DEI-GISHym 11597 D Euura sylvestris PR. 574 VV.

Fig ure 10. Characters of Euura bergmanni and Euura oligospila groups, males. A Euura respondens DEI-GISHym 84697 B Euura oligospila DEI-GISHym 84695 C Euura frenalis ZMUO. 033184 D Euura viridis DEI-GISHym 84547 E Euura brevivalvis DEI-GISHym 11624 F Euura bergmanni DEI-GISHym 84689 G Euura respondens DEI-GISHym 84697 H Euura oligospila DEI-GISHym 84695 I Euura brevivalvis ZMUO. 039090 J Euura bergmanni DEI-GISHym 84689 K Euura sylvestris ZMUO. 035654 L Euura oligospila DEI-GISHym 84695.

Figure 11. Penis valves of Euura bergmanni group. A Euura bergmanni ZMUO. 032583 B Euura dispar DEI-GISHym 88519 C Euura viridis ZMUO. 030834 D Euura brevivalvis DEI-GISHym 84227 E Euura brevivalvis ZMUO. 030870 F Euura sylvestris DEI-GISHym 83594 G Euura sylvestris ZMUO. 033416 H Euura glutinosae DEI-GISHym 84096 I Euura leptocephalus DEI-GISHym 88730 J Euura respondens DEI-GISHym 12514.

Figure 15. Euura dispar adults. Female ZMUO. 034987 (A, B), male ZMUO. 040517 (C, D). Identification of the female is uncertain.

Figure 19. Euura sylvestris adults. Female ZMUO. 038944 (A, B), males ZMUO. 035654 (C, D) and ZMUO. 035806 (E, F).

Figure 25. Euura sylvestris larvae. A, B Finland 2018 Salix caprea C, D Finland 2019 Populus tremula E Austria 2017 Salix hegetschweileri. Larvae of Euura sylvestris found on Populus tremula in Finland in 2019 appear morphologically different from larvae on Salix, but based on genetics represent Euura sylvestris.