Pristiphora coactula (Ruthe, 1859)

Liston, Andrew, Mutanen, Marko, Heidemaa, Mikk, Blank, Stephan M., Kiljunen, Niina, Taeger, Andreas, Viitasaari, Matti, Vikberg, Veli, Wutke, Saskia & Prous, Marko, 2022, Taxonomy and nomenclature of some Fennoscandian Sawflies, with descriptions of two new species (Hymenoptera, Symphyta), Deutsche Entomologische Zeitschrift 69 (2), pp. 151-218 : 151

Pristiphora coactula (Ruthe, 1859)

Nematus coactulus Ruthe, 1859: 307-308. ♀. Holotype. Type locality: Iceland.

Lygaeonematus (Lygaeotus) trochantericus Lindqvist, 1952: 101-102. ♀. Holotype (http://id.luomus.fi/GL.7708) and paratypes (♀, ♂). Type locality: Finland, Utsjoki, Outakoski. syn. nov.

Notes.

The nuclear sequence data obtained for this study revealed three main clusters within the Pristiphora carinata group: P. carinata , P. coactula , and P. borea + P. groenblomi + P. albilabris (Fig. 30 ). No nuclear sequence data are yet available for P. breadalbanensis (Cameron, 1882b) and P. lativentris (Thomson, 1871). A nearly perfect match morphologically to the L. trochantericus holotype is ZMUO.035514, which falls within the P. coactula cluster based on nuclear DNA (Fig. 30 ). There are two main clusters based on COI sequences, one of which contains only P. borea (Konow, 1904) and P. groenblomi (Lindqvist, 1952) and the other one all species (Fig. 31 ). Within the COI cluster containing all species (Fig. 31 ), P. borea , P. groenblomi , and P. albilabris (Boheman, 1852) ( Betula feeders) tend to separate from P. coactula ( Salix ) and P. carinata (Hartig, 1837) ( Vaccinium ). Based on the specimens having nuclear data, the species (mainly females) of the Pristiphora carinata group may be separated by the following key, although it might not always work for all specimens, particularly P. coactula and P. borea . Excluded from the key are the (sub)arctic species P. breadalbanensis and P. lativentris . Pristiphora Pristiphora lativentris may have somewhat different serrulae from the other species (almost papilliform, see fig. 215 in Prous et al. 2017). The identity of Pristiphora breadalbanensis (most similar to P. borea and P. coactula ) needs further research to confirm if characters (e.g. structure of median mesoscutal lobes) mentioned by Benson (1958) to separate this species are reliable.

1	a Pterostigma distinctly darker than costa b Legs largely orange or reddish c In female, valvifer 2 and terga 9-10 black or slightly pale d In male, sternum 9 blac	P. albilabris (Boheman, 1852) ♂♀ and P. groenblomi (Lindqvist, 1952) ♂♀ in part
-	aa Pterostigma similarly pale as costa or somewhat darker than costa bb Legs largely black to pale cc In female, valvifer 2 and terga 9-10 extensively pale dd In male, sternum 9 black to pale	2
2(1)	a Pterostigma somewhat darker than costa b Legs largely orange or reddish c Metafemur completely pale d In female, terga 2-8 and sterna black e In male, sternum 9 (always?) black	P. groenblomi ♂♀ in part
-	aa Pterostigma similarly pale as costa bb Legs largely black to yellowish cc Metafemur black to pale dd In female, terga 2-8 and sterna black or partly pale (starting from tergum 2 and sternum 2) ee In male, sternum 9 black to pale ... ♀ (males of the following species not separated)	3
3(2)	a Valvula 3 in dorsal view gradually narrowing, without invagination and with sharp tip (see figs 98-99 in Prous et al. 2017) b Usually only terga 8-10 or 9-10 extensively pale, but sometimes more (starting from tergum 5)	P. carinata (Hartig, 1837)
-	aa Valvula 3 in dorsal view more or less truncate, with or without indistinct invagination and with broader tip bb Usually terga 8-10 or more (starting from tergum 2) at least partly pale	4
4(3)	a Valvula 3 short, truncate and usually with indistinct invagination (Fig. 33C, D ) b Abdomen usually becoming gradually paler from base to apex, dorsally usually starting from tergum 7, laterally and ventrally from tergum 2 and sternum 2 c Metafemur usually completely pale d Clypeus usually mostly pale	P. coactula (Ruthe, 1859)
-	aa Valvula 3 usually longer, slightly narrowed at apex and without invagination (Fig. 33A ), but sometimes not distinguishable from P. coactula (Fig. 33B ) bb Abdomen usually slightly or extensively pale only at apex, dorsally usually terga 8-10, laterally usually terga 7-10, ventrally usually sternum 7 cc Metafemur black to completely pale dd Clypeus mostly black to mostly pale	P. borea (Konow, 1904)

Examples of lancets of P. borea , P. carinata , and P. coactula are shown in Fig. 32A-C , but more specimens need to be examined to check if there are any consistent differences between the species. Morphological differences between the males of P. borea , P. carinata , and P. coactula are not clear. Externally, it seems that P. coactula tends to be paler (clypeus, pronotal angles, tegula, metafemur, and sternum 9 completely or mostly pale) than P. borea and P. carinata . The dorso-apical margin of the paravalva of P. borea (Fig. 34B ) may be more strongly inclined basally compared to P. carinata and P. coactula , but differences between the penis valves of the latter two species are not clear (Fig. 34A, D, E ). The most distinctive penis valve in the P. carinata group seems to belong to P. albilabris (Fig. 34F ), which has the most distinctly inclined dorso-apical margin of paravalva. Overall shape of penis valve of P. groenblomi (Fig. 34C ) is most similar to P. borea , but it may be larger.

Figures

Figure 30. Maximum likelihood tree of Pristiphora carinata group based on nuclear genes (NaK and POL 2). Numbers at branches show SH-aLRT support (%) / ultrafast bootstrap support (%) values. Values of only well supported branches (> 90 for both) and of P. coactula clade with moderate support are shown. Letters " f " stand for " female ", " m " for " male ", and " l " for larva. Numbers at the end of the tip labels refer to sequence length and the number of heterozygous positions.

Figure 31. Maximum likelihood tree of Pristiphora carinata group based on mitochondrial COI gene. Numbers at branches show SH-aLRT support (%) / ultrafast bootstrap support (%) values. Values of only well supported branches (> 90 for both) are shown. Letters " f " stand for " female ", " m " for " male ", and " l " for larva. Numbers at the end of the tip labels refer to sequence length and the number of ambiguous positions.

Figure 32. Lancets of Pristiphora carinata group. A. P. coactula (ZMUO. 031490); B. P. borea (ZMUO. 033284); C. P. carinata (ZMUO. 031554).

Figure 33. Tip of abdomen of Pristiphora carinata group females in dorsal view. A. P. borea (ZMUO. 035517); B. P. borea (ZMUO. 033457); C. P. coactula (ZMUO. 046522); D. P. coactula (ZMUO. 035246).

Figure 34. Penis valves of Pristiphora carinata group. A. P. carinata (ZMUO. 031419); B. P. borea (DEI-GISHym 80148); C. P. groenblomi (DEI-GISHym 80210); D. P. coactula (ZMUO. 039225); E. P. coactula (DEI-GISHym 84186); F. P. albilabris (ZMUO. 032465).