Euura bergmanni (Dahlbom, 1835)

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 bergmanni (Dahlbom, 1835)

Figs 5M, N, R , 6A , 10F, J , 11A , 13 , 22

Nematus bergmanni Dahlbom, 1835: 24-25. Type locality: Sweden, Lund area. LT designated below.

Nematus virescens Hartig, 1837: 217. Type locality: not stated, but presumably Germany according to the title of Hartig’s publication. LT designated below.

Nematus pallicarpus Hartig, 1837: 215-216. Type locality: "in hiesiger Gegend" [Germany, Berlin area]. LT designated by Haris (1997).

Nematus validicornis Förster, 1854a: 341-342. Type locality: Germany, Aachen area. LT designated below. Syn. nov.

Nematus curtispina Thomson, 1871: 152-153. Type locality: "Probably as widespread as the previous species" [translated from Swedish], which presumably refers to N. brevivalvis : "Probably occurs throughout Scandinavia" [translated from Swedish]. LT designated below.

Nematus varipictus Holmgren, 1883: 147, Plate 2, Fig. 12 . Type locality: Matotschkin Scharr [Russia, Novaya Zemlya, Matochkin Strait]. 2 ST females were in NHRS ( Lindqvist 1944), but could not recently be found. Synonymy with Pteronidea curtispina by Lindqvist (1944).

Nematus anthophilus Zaddach, 1884 [in Brischke 1884]: 163-164. Type locality: not stated. Type material probably destroyed ( Blank and Taeger 1998). Synonymy with Pteronus curtispinis (Thomson) by Konow (1903b).

Amauronematus longicornis Konow, 1897: 179. Type locality: Russia, Irkutsk. LT designated below.

Lygaeonematus pallens Enslin, 1916: 500-501. Type locality: Germany, Dessau. LT designated by Taeger and Blank (1998).

Pteronidea curtispina var. luctuosa Enslin, 1916: 455. Type locality: Germany, Bavaria, Fürth. LT designated below.

Pteronidea vernalis Lindqvist, 1937: 130-132. Type locality: southern Finland (HT). Not found in MZH. Synonymised with Pteronidea curtispina by Lindqvist (1941).

Similar species.

Females are most similar to Euura oligospila group, E. respondens , and E. sylvestris . Head more rectangular in dorsal view compared to Euura oligospila group and E. respondens . Lancet usually broader and basal annular sutures usually less bent compared to E. sylvestris and E. respondens . Gap (cypsella) between serrulae small compared to Euura oligospila group. Males distinguishable from other species by distinct penis valves (see key). Length of postocellar area in E. bergmanni is not a reliable character to distinguish it at least from E. sylvestris . Females of overwintering generation are dorsally largely black, the later generations largely or nearly completely pale (pterostigma is always pale). Males of overwintering generation are largely black (except legs and abdomen ventrally to various degrees), including pterostigma; the later generations are ventrally largely or nearly completely pale (including pterostigma) but dorsally mostly black. At least in females there tend to be distinct differences between the generations also in the length of malar space and perhaps postocellar area. In overwintering generations, the malar space tends to be distinctly shorter (Fig. 5M ) than in later generations (Fig. 5N ).

Genetic data.

COI. Based on 13 specimens, maximum within species distance is 3.65% and the nearest neighbour, diverging by a minimum of 7.1%, is the Euura viridis subgroup. Only one BIN: BOLD:AAG3539.

Nuclear. Based on 5 specimens, maximum within species distance is 0.19% (0.23% based on haplotypes of individual females). The nearest neighbour, diverging by a minimum of 3.5%, is Euura viridis .

Host plants and behaviour.

Hosts: a wide variety of Salix species, including Salix alba , Salix fragilis ( Weiffenbach 1985), aurita, Salix viminalis ( Boevé 1990), Salix caprea , Salix pentandra , Salix phylicifolia ( Kangas 1985), and Salix purpurea ( Benander 1966). Lindqvist (1956) recorded up to four generations per year in Finland. Lindqvist (1941) stated that adults from the overwintering generation were very much darker than the next generation, and that adults of the 3rd and 4th generations were paler still. The characteristic continuous double dorsal line of the larva makes their identification usually straightforward. This double line is usually white in early generation larvae, but pink or even red in later generations.

Distribution.

Palaearctic ( Taeger et al. 2006; Sundukov 2017), possibly also Nearctic (one barcoded larva in BOLD, CHU06-COL-364). Specimens studied are from Finland, Germany, Russia (Irkutsk Oblast), Sweden, Switzerland, United Kingdom.

Type material.

Nematus bergmanni Dahlbom, 1835. Lectotype, here designated, ♀, MZLU2017334, MZLU. Dahlbom cited a publication by Bergman (1763), in which adults were mentioned, which Dahlbom considered to belong to this species. There is no trace of Torbern Bergman material in the UUZM collection (Hans Mejlon, personal communication: March 11, 2019). Following this citation, Dahlbom described a larva, evidently from his original observations: "Larva prasina linea dorsali lata livida vel purpurascente et utrinque fusco-marginata" [Larva leek green with broad blue or purplish band and dark-bordered at both sides], with the additional information [translated from Latin] "Frequently observed on willows around Lund in Scania from 26 August to 2 October". Although a label on the lectotype bears the date "14 Aug.", this might refer to the date of emergence of an adult reared from a larva, and therefore does not necessarily contradict Dahlbom’s statement.

Nematus virescens Hartig, 1837. Lectotype, here designated, ♀, GBIF-GISHym3456, ZSM. Koch (2000) mentioned this same specimen as LT, with details of its labelling, together with 2 “Paratypen”. This was not, however, a valid taxonomic act, because he omitted an explicit statement that he was designating this specimen (see ICZN 2003).

Nematus pallicarpus Hartig, 1837. LT, “Cotype”, " Nematus pallicarpus Htg. Th. Hartig det.", " Pteronidea curtispina Th. E. Clément det.", DEI-GISHym84734, ZSM. 6 female paralectotypes with similar labels to LT. Three males with similar labels cannot be syntypes: Hartig described only the female sex.

Nematus validicornis Förster, 1854. Lectotype, here designated, ♂, GBIF-GISHym3451, ZSM.

Nematus curtispina Thomson, 1871. Lectotype, here designated, ♀, MZLU2017334, MZLU [the same specimen as the LT of Euura bergmanni Dahlbom]. Koch (2000) mentioned this same specimen as LT, with details of its labelling. This was not, however, a valid taxonomic act, because he omitted an explicit statement that he was designating this specimen (see ICZN 2003).

Amauronematus longicornis Konow, 1897. Lectotype, here designated, ♂, GBIF-GISHym3849, SDEI. Penis valve mounted on a separate slide ( Symphyta Coll. Nr. 233). The lectotype designation indicated by a label by Zinovjev is unpublished. Lindqvist (1972: 71) studied this male and called it “♂-Typus”; but since he also mentioned a “♀-Typus”, which could not be found at the SDEI, his action is not a lectotype designation.

Lygaeonematus pallens Enslin, 1916. LT, ♀, DEI-GISHym84733, ZSM.

Pteronidea curtispina var. luctuosa Enslin, 1916. Lectotype, here designated, ♂, GBIF-GISHym3339, ZSM.

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 6. Lancets of Euura. A Euura bergmanni DEI-GISHym 12585 B Euura leptocephalus holotype NHRS-HEVA 000003974 C Euura poecilonota DEI-GISHym 21400 D Euura hypoxantha DEI-GISHym 12505.

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 12. Penis valves of Euura. A Euura oligospila DEI-GISHym 21395 B Euura frenalis DEI-GISHym 12057 C Euura poecilonota? DEI-GISHym 12527 D Euura hypoxantha syntype GBIF-GISHym 3301.

Figure 13. Euura bergmanni adults. Females ZMUO. 040825 (A, B) and ZMUO. 039814 (C, D), males ZMUO. 035691 (E, F) and ZMUO. 040823 (G, H).

Figure 22. Euura bergmanni larvae. A Finland 2019 Salix fragilis B, C Finland 2020 Salix sp. D Finland 2019 Salix glauca / lapponum. Larvae of the first generation (A-C) are typically with white double dorsal line, while those of the later generations (D) are usually with pink or reddish dorsal line.