Euura leucapsis (Tischbein 1846) : Prous et al. 2014
- Dataset
- North European gall-inducing Euura sawflies (Hymenoptera, Tenthredinidae, Nematinae)
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Insecta
- order
- Hymenoptera
- family
- Tenthredinidae
- genus
- Euura
- species
- Euura leucapsis
description
Kopelke (2007 b) regarded Phyllocolpa alienata and P. leucapsis as separate species, monophagous respectively on Salix aurita and S. cinerea. The main morphological characters presented in his key to distinguish them were the length: breadth index of valvulae 3 in dorsal view and very slight differences in the profile of valvula 3 in lateral view. The key states that ctenidia are present on the lancet from annulus 3 in both taxa, although his Figure 1 d (leucapsis) shows these as present from annulus 2. All these characters are somewhat variable and are not correlated with the host plants. The penis valves are practically indistinguishable, as are Kopelke's drawings of these. On the other hand, specimens from S. aurita tend to be darker than those from S. cinerea. This applies to the coloration of the head, pronotum, femora and cerci, but a complete spectrum of intermediate specimens exists. Possibly the trend is merely a reflection of the generally cooler sites, often in more northern or upland areas, where S. aurita is the main host. Nearly the same applies to Phyllocolpa rolleri, which represents an even darker extreme than P. alienata, on the same continuum of variability. In view of these considerations, and the lack of evidence for a genetic difference, we propose the synonymy of these three taxa. Blank et al. (2009) followed the error made by Kopelke (2007 b: in the text), and treated coriacea (Benson) as a synonym of alienata. However, it was Kopelke's intention to place coriacea as a synonym of leucapsis (Kopelke 2007 b: in the abstract), as noted by Taeger et al. (2010). Variability. Female: Body length: 3.1 – 4.1 mm. Male: 3.3 – 3.8 mm. See also above (Notes on types and taxonomy). Total number of specimens examined: 21. Genetic data. COI barcodes of five German leucapsis specimens from S. cinerea and five German and Scottish specimens from S. aurita were identical. The barcodes of E. acutiserra, morphologically the most similar north European species, differ from leucapsis by an approximate minimum of 3.0 %. Bionomics. Host plants: Salix cinerea (Kopelke 2007 b), S. aurita (Kopelke 2007 b: as alienata), and S. silesiaca (Liston 2011: Salix hastata, reported in the original description as the host of rolleri, was a misidentification). A larva collected from S. lapponum by TN (tree: 5 x _ Euura _ acutiserra _ Salix _ lapponum) was identified by its barcode as E. leucapsis. Perhaps this represents a case of oviposition on an atypical host. Biology: Kopelke (2007 b).
distribution
Distribution. Central and North Europe, north to Finnmark (Kopelke 2007 b), Russian Far East (Zhelochovtsev & Zinovjev 1995), Canada (Benson 1962). Occurrence in Sweden: published records; Skåne (Benander 1966, as Pontania coriacea on S. cinerea and S. aurita), Halland, Torne Lappmark (Coulianos & Holmåsen 1991). Material examined: Skåne, Hälsingland.