Empria longicornis species group: taxonomic revision with notes on phylogeny and ecology (Hymenoptera, Tenthredinidae)

Abstract

The Empria longicornis species group (Hymenoptera, Tenthredinidae) is revised. Empria japonica Heidemaa & Prous, sp. nov. is described from Japan. The lectotypes of Empria gussakovskii Dovnar-Zapolskij, 1929, E. konowi Dovnar-Zapolskij, 1929, Poecilosoma longicornis Thomson, 1871, P. mongolica Konow, 1895, and P. tridens Konow, 1896 are designated. Empria konowi Dovnar-Zapolskij, 1929 (syn. nov.) and E. gussakovskii Dovnar-Zapolskij, 1929 (syn. nov.) are synonymized with E. tridens (Konow, 1896), and Empria waldstaetterense Liston, 1980 (syn. nov.) with E. alector Benson, 1938. Empria alpina Benson, 1938 and E. minuta Lindqvist, 1968, earlier misidentified as E. gussakovskii, are treated as valid species. Nine species are confirmed to belong in the longicornis-group: E. alector, E. alpina, E. basalis, E. japonica, E. loktini, E. longicornis, E. minuta, E. mongolica, and E. tridens. Distributional data of the species and a key to the imagines are provided. Ex ovo rearings of the four most common and often misidentified species in the group (E. alector, E. basalis, E. longicornis, and E. tridens) were carried out to verify their host plants and male conspecifics. External morphology, morphometrics (geometric and traditional), and DNA sequences (mitochondrial COI and nuclear ITS1 and ITS2) are used to delimit species within the group and to assess their phylogenetic relationships. Mitochondrial DNA sequences analyzed are mostly regarded as unsuitable for species circumscription, DNA barcoding and for reconstructing species phylogeny within the group. In this regard, analyses of the ITS sequences yielded more concordant results.

Review of the sawfly genus Empria (Hymenoptera, Tenthredinidae) in Japan

“…With 51 valid species-level taxa (Taeger et al 2010; Prous et al 2011b), Empria Lepeletier & Serville, in Latreille et al 1828 is one of the largest genera in the Allantinae. Nevertheless, it still remains rather poorly studied in comparison with other tenthredinid sawflies.…”

“…Fortunately, their genitalia frequently possess clear differences even between closely related species mostly enabling their reliable identification. Though the knowledge on most of the European Empria species can be regarded as satisfactory (Zhelochovtsev and Zinovjev 1988; Prous et al 2011b), very little is known about Eastern Palaearctic species. According to Takeuchi (1952a), more than seven Empria species had been found in Japan, but most of them remained unidentified.…”

“…Until recently, only two species had been identified (Takeuchi 1952a; b; Abe and Togashi 1989), and one of them, Empria pallipes (Matsumura 1912), actually belongs to Monsoma MacGillivray, 1908 (see results). Prous et al (2011b) reported three additional species. Here we report 11 species from Japan, two of them described as new.…”

“…Some preliminary results based on a limited number of species can be found in Prous et al (2011b), which focuses on the Empria longicornis species group. Only few intrageneric groups have been proposed, which might be monophyletic.…”

“…Within Empria s. str., the Empria hungarica (Konow, 1895) (see Heidemaa and Viitasaari 1999) and the Empria longicornis (Thomson, 1871) species groups (see Prous et al 2011b) have been proposed. In addition, the Empria immersa species group can be defined for the species possessing highly similar penis valves, which have a characteristic long apical spine (Smith 1979; Zhelochovtsev and Zinovjev 1988; Prous et al 2011b).…”