Pristiphora subopaca Lindqvist, 1955

Pristiphora subopaca Lindqvist, 1955: 41-42. Holotype ♀ (http://id.luomus.fi/GL.5202) in MZH, examined. Type locality: Munksnäs, Uusimaa, Finland.

Pristiphora coniceps Lindqvist, 1955: 39-40, syn. n. Holotype ♀ (http://id.luomus.fi/GL.5207) in MZH, examined. Type locality: Pihtipudas, Central Finland, Finland. Note. The male paratype (http://id.luomus.fi/GL.5208) is not conspecific with the holotype female and belongs to P. melanocarpa; therefore most records of P. coniceps in the literature based on the penis valve belong to that species.

Pristiphora brunniapex Lindqvist, 1960: 37-38, syn. n. Holotype ♀ in MZH, examined. Type locality: Pisa, Rovaniemi, Finland.

Similar species.

Based on the external morphology, the most similar species are P. albitibia, P. confusa, P. opaca, P. pusilla, and P. sootryeni . The species is best distinguished through the structure of male penis valve (Figs 91-92). Unfortunately, it is rather difficult to separate females from P. confusa and P. opaca as the differences in the lancets are small (Figs 62 - 69). Apical serrulae are perhaps less protruding and longer (Figs 66-69) than in P. confusa (Figs 62-63) and the basal part of the tangium lacks a fold that is present in P. opaca (Figs 64-65). Externally, the pterostigma is uniformly yellow (Fig. 27) unlike in P. confusa and P. opaca, in which the pterostigma is basally dark brown and apically brown (Fig. 28). In addition, the claws of P. subopaca tend to have a larger subapical tooth (Fig. 32) than in P. opaca (Fig. 31). Among the males, the most similar penis valves are of P. confusa and P. pusilla . The ventro-apical spine is bent more strongly and the pseudoceps is broader (Figs 91-92) than in P. confusa (Figs 89-90). Compared to P. pusilla (Figs 93-94), the ventro-apical spine is bent less strongly and the dorsal depression in the middle of pseudoceps is less distinct, which is clear only when compared to the left penis valve of P. pusilla (Fig. 93). The holotype of Pristiphora coniceps Lindqvist does not differ in any significant way from the holotype of Pristiphora subopaca Lindqvist. The characters mentioned in the structure of the head and thorax for Pristiphora coniceps in the original description (Lindqvist 1955), that are supposed to differentiate this species from others in the Pristiphora ruficornis group, are minute and unreliable. The characters that help in species identifications in closely related species (colour of pterostigma and antennae, degree of coriaceous sculpture of mesepisternum, size of subapical tooth of claws, and the structure of the lancet) are not different between the holotypes of Pristiphora coniceps and Pristiphora subopaca . The host ( Salix) mentioned for Pristiphora coniceps in the original description (Lindqvist 1955) and by Kangas (1985) (as Salix caprea L.) also fits with the data recorded for P. subopaca (Lindqvist 1965; Kangas 1985). Consequently we treat Pristiphora coniceps as a synonym of Pristiphora subopaca . We also treat Pristiphora brunniapex Lindqvist as a rare colour form (only the holotype and one additional female are known to us) of Pristiphora subopaca Lindqvist, because the only difference is that Pristiphora brunniapex has a pale tip of the abdomen (terga 7-10 or 8-10; Figs 10, 12). Based on the second known specimen (DEI-GISHym20899, deposited in MZH) reared by J. Perkiömäki from Salix sp. (near Helsinki, Finland), we can say that the host is not different from Pristiphora subopaca either. Although the lancet of Pristiphora brunniapex cannot be distinguished from P. aphantoneura, P. luteipes and P. staudingeri, these species can be separated from Pristiphora subopaca - Pristiphora brunniapex by having different host ( Lathyrus pratensis for P. aphantoneura), yellow metafemur ( P. aphantoneura and P. luteipes), or as in P. staudingeri usually strongly coriaceous sculpture of mesepisternum and different habitat (arctic or subarctic).

Genetic data.

Based on COI barcode sequences, P. subopaca belongs to the same BIN cluster (BOLD:AAG3568) as P. aphantoneura, P. bifida, P. confusa, P. opaca, P. pusilla, and P. staudingeri (Fig. 1). The nearest neighbour (BOLD:AAQ2302, P. armata and P. leucopus) is 2.76% different. Only one TPI sequence is available, which can be distinguished from other species (Fig. 2).

Host plants.

Salix caprea L. (Lindqvist 1965; Kangas 1985) and S. phylicifolia L. (Lindqvist 1965).

Distribution and material examined.

Western Palaearctic. Specimens studied are from Finland and Sweden.