Pristiphora confusa Lindqvist, 1955

Pristiphora confusa Lindqvist, 1955: 40-41. Holotype ♀ (http://id.luomus.fi/GL.5209) in MZH, examined. Type locality: Sipoo [Sibbo], Uusimaa, Finland.

Similar species.

Based on the external morphology, the most similar species are P. albitibia, P. armata, P. leucopus, P. opaca, P. pusilla, P. sootryeni, and P. subopaca . The species is best distinguished through the structure of male penis valve (Figs 89-90). Unfortunately, it is rather difficult to distinguish females from P. armata, P. leucopus, P. opaca, and P. subopaca, as the differences in lancets are small (Figs 54-57, 62 - 69). Apical serrulae are more protruding and shorter than in P. opaca and P. subopaca (Figs 62 - 69). Pristiphora opaca also has a fold at the base of tangium of the lancet (Figs 64-65) that is lacking in other species in the Pristiphora ruficornis group. Pristiphora opaca tends also to have a smaller subapical tooth than P. confusa . The pterostigma of P. confusa is apically brown and basally dark brown, like in P. opaca (Fig. 28), but unlike in P. subopaca, in which it is uniformly yellow (Fig. 27). In P. armata and P. leucopus, the pterostigma is usually dark brown (Fig. 29), but sometimes the pterostigma can have more or less the same colour as in P. confusa . In this case, small differences in the lancet can help distinguish P. confusa from P. armata and P. leucopus, as ctenidia tend to be more distinct in P. confusa (Figs 54-57, 62-63). Among the males, the most similar penis valves are of P. subopaca . The ventro-apical spine in P. confusa is barely bent and the pseudoceps is narrower compared to P. subopaca (Figs 89-92).

Genetic data.

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

Host plants.

Salix caprea L. (Kangas 1985), Salix fragilis L. (Benson 1958), Salix phylicifolia L. (Benson 1958).

Distribution and material examined.

Western Palaearctic. Specimens studied are from Estonia, Finland, France, Germany, Sweden, and Switzerland.