Aprostocetus catius (Walker, 1839)

Aprostocetus catius (Walker, 1839) View in CoL

Fig. 12

Material examined. 79 ♀♀, 90 ♂♂: IRAN, West-Azarbaijan Province , Naqadeh, Solduz Wetland, 37º02′ N, 45º35′ E, 1277 m a.s.l., 21 July 2020, 29 April 2021, Y. Karimpour leg., ex Calamagrostis epigejos GoogleMaps .

Diagnosis (abstracted from Walker 1844; Graham 1987). The female of A. cutius ( Fig. 12B,D) differs from A. emesa (Walker, 1839) exclusively in two diagnostic characters given in the female identification key provided by Graham (1987), namely: the relative lengths of the ovipositor sheaths and postcerci compared to the metatibia (0.40–0.63× and 2.9–3.6×, respectively), and the proportional lengths of the fore wing marginal vein versus the stigmal vein (0.75–0.90× and 3.6–4.0×, respectively). Additionally, the gaster (excluding the ovipositor sheaths) is 1.3–1.5× as long as the combined length of the head and mesosoma and 2.6–2.9× its own width, with slightly curved lateral margins in its distal portion. To date, the male of this species has remained undescribed, and its biology is unknown; however, this study presents the first description and photographic documentation of the male.

Males ( Fig. 12A,C) exhibit comparable coloration and dimensions to those of females: scape 2.5× its width outer surface with several setae positioned away from the ventral edge, and with. a ventral plaque approximately one-third the length of the scape; combined length of the pedicel and flagellum about 2.2× width of the mesoscutum; pedicel approximately1.9× as long as wide, distinctly exceeding length of Fu 1; pedicel noticeably thicker than funicle and filiform in shape. Fu 1 slightly shorter than Fu 2 and 1.5× its width, and subsequent funicular segments nearly equal in length, each about twice as long as their width; clava marginally wider than Fu 4, its length equivalent to that of Fu 3 plus Fu 4, and approximately four times as long as wide; C 1 and C 2 equal in length, each 1.2× its width, C 3 relatively short, nearly equal in length and width; and gaster pale, 1.5× the length of mesosoma, and twice as long as wide.

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

Biological association. No host associations have been formally documented for this species. However, existing host records of congeneric species are Diptera , specifically Cecidomyiidae and Agromyzidae ( Graham 1987; UCD Community 2023). Considering that specimens from both dipteran families were collected from Calamagrostis spp. , there is a probable ecological association between this genus and these gall-forming/flower-head inhabiting dipterans.