Pagastia Oliver, 1959

Makarchenko, Eugenyi A., 2019, Review of the genus Pagastia Oliver (Diptera: Chironomidae: Diamesinae) from North America, with description of P. (P.) subletteorum sp. nov., Zootaxa 4664 (1), pp. 115-128 : 116

Genus Pagastia Oliver

Pagastia Oliver, 1959: 49 .

Type species: Pagastia orthogonia Oliver, 1959 , by original designation.

Diagnosis. As in Oliver (1959, 1983, 1986, 1989), Oliver & Roussel (1982), Makarchenko (1985, 1994, 2006), Makarchenko & Makarchenko (2000), † Saether & Andersen (2003) and Endo (2004), with the emendations and additions below for the adult male.

Adult male. Medium to large sized species, 4–7 mm long.

Antenna. Pedicel with 3–4 setae. Flagellum with 13 flagellomeres and well developed or slightly reduced setae of plume; flagellomeres 1–4 and 13 with sensilla chaetica. Antennal ratio 1.0–4.2.

Head. Eye hairy, pubescent or naked, strongly extended dorsomedially. Temporal setae numerous, consisting of inner and outer verticals, postorbitals and sometimes orbitals; frontals absent. Tentorium swollen basally, with or without microtrichia. Cornua of cibarial pump with blunt and somewhat irregular tip. Palp with 5 palpomeres; palpomere 3 with sensilla capitata.

Thorax. Antepronotal lobes well developed, separated by wide V- shaped notch; dorsomedial and ventrolateral antepronotals present, or sometimes entire lobe covered with setae. Acrostichals long; dorsocentrals in 1–5 rows; prealars extending anterior to level of median anepistemum II, sometimes almost to parapsidal suture; scutellars multiserial.

Wing. Grayish or gray. Membrane with or without setae on apex. Anal lobe well developed and often protrude forward, angular or rounded. Costa moderately produced; R 2+3 ending about midway between ends of R 1 and R 4+5; FCu proximal to MCu. R 4+5 with or without setae. M 1+2, M 3+4, Cu 1 sometimes with setae. Squama with numeroue setae in 2–3 rows. Alula with or without setae.

Legs. Fore leg with or without pseudospurs; mid leg with pseudospurs on tarsomeres 1 and 2; hind leg with pseudospurs on tarsomere 1 and usually on tarsomere 2; sensilla chaetica absent or present on tarsomere 1 of hind leg. Tarsomere 4 cylindrical, equal to or slightly longer than tarsomere 5.

Hypopygium. Tergite IX with or without anal point. When anal point present it is narrow, without setae and with or without apical peg. Phallapodeme moderately sclerotized; aedeagal lobes rarely reduced, but usually moderately to strongly sclerotized; lateral or lateral and median aedeagal lobes present. Gonocoxite with well developed or small basal lobe; transverse sternapodeme broadly arched. Gonostylus with or without short megaseta, simple or with small basal lobe.