Protonemura sp. (aculeata, Theischinger, 1976

Murányi, Dávid, Manko, Peter, Kovács, Tibor, Vinçon, Gilles, Žiak, Matej, Kerimova, Ilhama G., Snegovaya, Nataly Yurievna & Oboňa, Jozef, 2021, Review and contribution to the stonefly (Insecta: Plecoptera) fauna of Azerbaijan, Zootaxa 4975 (1), pp. 58-80 : 68-69

Protonemura sp. (aculeata ?)

Şəki-Zaqatala region: 33: 1♂ (HNHM) 1♂ (LMEE).

Remarks. One of these two, relatively large sized males (the HNHM specimen) was found to be infected by nematode worms of the family Mermithidae ( Figs. 15–17 ). The presence of mermithid worms in stoneflies were reported by Ravizza & Zwick (2006) from Italy and Germany, where they found several infected specimens belonging to Isoperla rivulorum ( Pictet, 1841) , Protonemura caprai ( Aubert, 1954) and another but unidentifiable Protonemura species. Lesions caused by the nematode infection show remarkable similarity between the Azerbaijan specimen and those figured and described by Ravizza & Zwick (2006). These include the fusion of the ventral vesicle with the hypoproct, shortening and fusion of paraproct lobes, and the shortening of epiproct ( Figs 11–14 ).

The other specimen (kept in the LMEE), was found to be free of mermithids, and its terminalia shows no lesions but apparently it was conspecific with the infected specimen. They belong to the praecox group, and cannot convincingly be attributed to any of the described species. Since Zhiltzova (1988) reported high geographical variability of P. aculeata within the Caucasian region, we will consider our specimens as a probable variant of P. aculeata , rather than a new species. Needed are additional specimens in good condition, additional character states in the form of DNA sequences, and behavioural characters derived from bioacoustic studies.

Figures

FIGURES 15–17. Mermithids from Protonemura sp. (aculeata?) male from the Greater Caucasus—15: mermithids as seen by transparency through the abdominal sterna; 14: four mermithid specimens dissected from the male stonefly, according to mm scale; 17: abdomen of the stonefly opened at segments 2 and 3, with mermithids protruding.

FIGURES 11–14. Mermithid infected Protonemura sp. (aculeata?) male from the Greater Caucasus—11: terminalia, ventral view; 12: same, lateral view; 13: same, dorsal view; 14: same, dorsocaudal view—scale 1 mm.