Tetramesa eximia (Giraud, 1863)

Tetramesa eximia (Giraud, 1863) View in CoL

Figs 21, 22

Material examined. 114 ♀♀, 72 ♂♂: IRAN, West-Azarbaijan Province , Naqadeh, Solduz Wetland, 37º02′ N, 45º35′ E, 1277 m a.s.l., 21 July 2020, 29 April 2021, M. Razmi leg., ex Calamagrostis epigejos GoogleMaps .

Diagnosis (abstracted from Claridge 1961; Zerova 1978). Female ( Fig. 21B): body elongate, with long gaster exceeding combined length of head and mesosoma; color predominantly black, with legs bright rufous except femora basally dark fuscous, especially the metafemora darkened; wings ( Fig. 22E) hyaline with dark yellow veins ( Fig. 22F); pronotal spots very small and in dorsal view not well discernible ( Fig. 22A,B); head and mesosoma finely reticulate with dense pits ( Fig. 22A,B); gaster with fine sculpture except on the first two tergites ( Fig. 21B); antenna short with fine reticulate sculpture and sparse setae, Fu 1 2× as long as wide, Fu 2 –Fu 6 slightly longer than wide, Fu6 clearly separated from apical two segments which together with it form a distinct club ( Fig. 21A); mesosoma ( Fig. 22A,B) broad and convex; propodeum rugulose ( Fig. 22C) with a deep median furrow; gaster ( Fig. 21B) lanceolate and elongate, with distinct alutaceous sculpture on tergites 3‒8.

Male ( Fig. 21D): similar in sculpture and color to female but slightly smaller, with scape and pedicel entirely black, and legs, especially tibiae, conspicuously darker; antenna ( Fig. 21C) long and thin, with funicular segments elongate and slender, slightly convex and gradually decreasing in length towards apex, with sparse, short setae.

Remarks. Females of T. eximia are easily distinguished from related species by the antenna lacking a distinct club ( Fig. 21A), very small pronotal spots ( Figs 21B, 22A,B) and its longer lanceolate gaster ( Fig. 21B) ( Claridge 1961; Zerova 1978). The specimens obtained in this study were slightly smaller in body size compared to the measurements reported by Claridge (1961) and Zerova (1978).

Distribution. IRAN: West Azarbaijan Province ( new record). EXTRALIMITAL: Europe, former USSR, Turkey ( UCD Community 2023).

Biological association. These gall-stem wasps associated with C. epigejos ( Poaceae ). The species exhibits a biennial life cycle in Britain, with larvae developing in the stems of C. epigeios ( Claridge, 1961) .