Pristiphora ruficornis (Olivier, 1811)

Nematus ruficornis Olivier in Olivier and Manuel 1811: 167. Syntype(s) possibly in MNHN, not examined. Type locality: near Paris, France.

Pristiphora testaceicornis Serville, 1823: 75. Syntype(s) ♂ not found in MNHN (Lacourt 2000). Type locality: Paris, France.

Pristiphora testaceicornis Lepeletier, 1823: 60. Primary homonym of Pristiphora testaceicornis Serville, 1823 [= Pristiphora (Pristiphora) ruficornis (Olivier, 1811)]. Syntype(s) ♂ not found in MNHN (Lacourt 2000). Type locality: Paris, France.

Nematus (Nematus) robustellus Dahlbom, 1835b: 9. Type(s) not available. Nomen nudum.

Nematus fraxini Hartig, 1837: 204. Lectotype ♀ (GBIF-GISHym3285; here designated) in ZSM, examined. Type locality: Harz, Germany.

Nematus testaceicornis Jacobs, 1884: XXIII-XXIV. Syntype(s) ♀ possibly in IRSNB, not examined. Type locality: near Brussels, Belgium.

Nematus (Pristiphora) ruficornis var. integer Hellén, 1948: 116, syn. n. Primary homonym of Nematus integer Say, 1836. Holotype ♀ (http://id.luomus.fi/GL.5212) in MZH, examined. Type locality: Hammaslahti, North Karelia, Finland.

Similar species.

The most similar species is P. melanocarpa, which has darker antennae compared to P. ruficornis . Females have a distinctly paler ventral side of antennae (Fig. 25), while antennae in P. melanocarpa are uniformly black (Fig. 24) or have only a slightly paler ventral side. Males of P. ruficornis also have generally paler antennae than in P. melanocarpa (Fig. 26), but penis valves should be studied to distinguish them from P. melanocarpa specimens having conspicuously pale antennae. Ventro-apical spine of penis valve (Figs 79, 81) bends more gradually (forming a half circle) and is usually broader than in P. melanocarpa (Figs 80, 82).

Genetic data.

Based on COI barcode sequences, specimens of P. ruficornis are divided between two BIN clusters (BOLD:ACZ4465 and BOLD:ACZ4466) that also include P. melanocarpa (Fig. 1). Minimal distance between these two clusters is only 1.13%. Nuclear TPI sequences do not support separation of P. ruficornis from P. melanocarpa either (Fig. 2). The single sequenced male would be identical to one of the heterozygous P. melanocarpa females when ambiguous positions due heterozygosity are excluded. Examination of all the 14 heterozygous sites (double peaks in chromatograms) in this P. melanocarpa specimen revealed that all of them include also the nucleotide found in P. ruficornis, possibly indicating haplotype sharing between these two taxa.

Host plants.

Betula pubescens Ehrh. ssp. czerepanovii (N. I. Orlova) Hämet-Ahti (rearings and ex ovo rearing experiments by VV).

Distribution and material examined.

Western Palaearctic. Specimens studied are from Finland, Germany, Portugal, and Sweden.