Rhyacophila ferruginea (Scopoli)

Valladolid, María, Arauzo, Mercedes, Chertoprud, Mikhail V., Chvojka, Pavel, Czachorowski, Stanisław, Dorda, Beatriz A., Hinić, Jelena, Ibrahimi, Halil, Karaouzas, Ioannis, Krpač, Vladimir, Kučinić, Mladen, Lodovici, Omar, Salokannel, Juha, Stamenković, Valentina Slavevska & Stojanović, Katarina, 2021, The Rhyacophila fasciata Group in Europe: Rhyacophila fasciata Hagen 1859 and formerly synonymized species (Trichoptera: Rhyacophilidae), with new description of Rhyacophila fasciata and Rhyacophila septentrionis McLachlan 1865 (stat. prom.)., Zootaxa 4975 (1), pp. 1-57 : 13-14

Rhyacophila ferruginea (Scopoli) , nomen dubium

Phryganea ferruginea Scopoli, 1763: 266 , fig. 691.

Rhyacophila ferruginea (Scopoli) : Hagen, 1859: 153.

The original description of this species, as Phryganea ferruginea ( Figs 1a, 1b ) was:

“ Phryganea ferruginea . Length of 6 1/3 lines [supposedly French lines, that gives approximately 14.287 mm of length. M.A. Alonso Zarazaga, personal communication].

Diagnosis. All rust colored; forewings reticulated dark; black eyes. In forests by the waters; month of May. Abdomen with lateral black dots, as many as segments of it. Antennae 6 lines long, rusty. The other sex with a round white common spot, and white spots (5–6) on the outer margin of the forewings.”

Hagen (1854), in his study of the species of Phryganea included in Scopoli’s Entomologia Carniolica stated that the description of P. ferruginea does not match the drawing, even with other Phryganea . Following the “reticulate wings” and “white spots” of wings, he proposed three options that could be one of the following: Chaetopteryx villosa ( Fabricius, 1798) (based on body contour and reticulation of wings), one of two Hydropsyche Pictet 1834 , and one Rhyacophila (reticulation of wings); the color (all rust) only matched with the mentioned Rhyacophila (maybe R. nebulosa Stephen ), and, as he had only the female, he couldn’t check if males also had the white spots on the wings.

In 1859 Hagen cited this species and R. fasciata , together with R. vulgaris , R. dorsalis and R. paupera : “4. R. ferruginea Scop. Anal appendage rounded, almost completely covering the lateral appendages. The smallest species. Carniola, Austria. Maybe dark colored females of my collection from Zurich belong to it.”

“5. R. fasciata Hag. The appendages are very similar to the previous species, but the size of the animal is much more significant and the upper wings have three dark cross-ties. A single male from Elberfeld”.

McLachlan (1865), at the end of his description of Rhyacophila septentrionis wrote: “I have some doubt in announcing this as a new species, since the form of the appendices agrees very well with the figure of those of R. ferruginea , sent to me by Dr. Hagen. I submitted an example to that gentleman, and he says that it is larger and darker than his continental types of that species and may be distinct. R. ferruginea is described as ‘die kleinste Art’ of the group (the true genus Rhyacophila ) to which it belongs”. In his publication of 1868, McLachlan said: “ R. ferruginea, (Scopoli) Hagen. I have not seen this insect, which, according to Hagen (in litt.) is smaller than septentrionis , but with similar lobes and appendices. Scopoli’s name cannot be said to apply to this species with certainty.” Finally, in his publication of 1879, McLachlan concluded at the end of the paragraph about Rhyacophila septentrionis : “I do not feel justified in adopting Scopoli’s name ferruginea (as was done by Hagen for the example from Carniola). Even supposing that Scopoli had a Rhyacophila before him (which is just possible), the particular species must remain uncertain.” We agree with this statement, due to the difficulty of identification from the original species described, so we propose to change the status of Rhyacophila ferruginea ( Scopoli 1763) to nomen dubium.

Figures

FIGURE 1. Original description of Rhyacophila ferruginea (Scopoli 1763) in Entomologia Carniolica, downloaded from Biodiversity Heritage Library (BHL). 1a, drawing and label. 1b, description (Scopoli 1763).