Spritella, Kerr, Peter H., 2014

Kerr, Peter H., 2014, The sequoia-loving sprite, a new genus and species of fungus gnat (Diptera, Mycetophilidae) from California, ZooKeys 437, pp. 109-126 : 112-113

Taxon classification Animalia Diptera Mycetophilidae

Spritella gen. n.

Type species.

Spritella sequoiaphila gen. et sp. n., by current designation.

Diagnosis.

Three ocelli, antennae with 14 cylindrical flagellomeres, maxillary palpus 4-segmented, scutum raised above level of head, upper half of anepisternum with setae, ventro-posterior area of katepisternum with microsetae, tibial spurs 1:2:2. Wing membrane with macrotrichia; costa produced beyond tip of R5; subcosta long, ending at C, approximately at midpoint of wing; sc-r present, arising beyond origin of Rs; r-m missing because Rs and M1 touching or r-m present, short; M2 arising from discal cell basad of origin of Rs or at base of M1; cubital vein unforked, A1 well developed, reaching beyond origin of Rs. Male gonostylus without basal appendages.

Spritella gen. n. resembles Acnemia Winnertz by its lack of a posterior fork and foreshortened medial stem. However, the new genus is readily separated from Acnemia by the presence of setae on the anepisternum and katepisternum; sc-r arising well beyond origin of Rs; and by having male gonostylus without a basal process. Other sciophiline genera that also lack the cubital fork include Afrocnemia Matile, Cluzobra Edwards, Monoclona Mik, and Parvicellula Marshall. In the new genus, crossvein sc-r is clearly present unlike in Afrocnemia and Cluzobra ; R4 is absent unlike in Parvicellula ; and the macrotrichia of wing membrane are decumbent, directed toward wing apex unlike in Monoclona . The long subcostal vein of Spritella gen. n. (relative to wing length) and position of sc-r relative to Rs is also distinctively different from these genera.

Description.

Head shape in anterior view subequal, approximately as long as wide; medial eye margins farther apart dorsally than ventrally; antennal eye notch present, at least two ommatidia deep; interommatidial setulae present between all ommatidia; ocelli three, nearly linear; lateral ocellus between 1 × and 1.5 × its own diameter from eye margin, between 2.5 × and 3 × its own distance from median ocellus; all ocelli dorsad of eye margin; occipital suture from median ocellus to occiput absent; frontal suture between median ocellus and ventral margin of frons complete, suture between lateral ocelli and eyes also present; frons with setae; face approximately 2 × longer than wide, parallel-sided along most of length, bearing setulae throughout; face and clypeus separated by complete suture; clypeus ovate, approximately one-half length of face, covered with short setae. Antennal scape and pedicel subequal in size; scape with setae approximately 2 × scape length; pedicel setae approximate length of pedicel; antennal flagellomeres 14, cylindrical, approximately 3 × longer than wide, approximately the same length but thinner distally, densely covered with short setae. Palp with 4 visible segments, none with apparent sensory pit.

Thorax (Fig. 2) raised, scutum dorsad of head position; short setae distributed throughout scutum, acrostichal setae present, bristles present along lateral margins of scutum; postalar wall and callus separated by carina; scutellum clearly wider than long, narrower than scutum; antepronotum and proepisternum with bristles; anepisternum with setae dorsally; anterior basalare bare; anapleural suture incomplete; katepisternum with setae ventro-posteriorly; anepimeron bare; anepisternum with few inconspicuous setulae; laterotergite raised ventrally, with bristles and shorter setae; metepisternum bare; mediotergite with three bands of bristles ventrally and shorter setae that extend along dorsoventral length, medially. Wing membrane covered with microtrichia and macrotrichia that are arranged irregularly; C ending beyond R5; dorsal surface of humeral vein without setae, ventral surface with setae; subcostal vein setose on both sides, ending in C, approximately at midpoint of wing; sc-r present, arising distad of origin of Rs; R1 setose on dorsal and ventral surfaces, although bare basad of Rs vein ventrally; vestigial M vein within discal cell present or absent; R4 not present, r-m present or absent (R5 joining M1 at junction with Rs); M1 setose above, bare below; M2 setose above, bare below, either arising from bM, from junction of M1 and Rs, or from base of M1; cubital vein unforked, setose above, bare below, ending at wing margin; CuP strong at base, extending apically as weak fold; anal vein strong, setose on both sides (less so ventrally), extending beyond origin of Rs. Legs elongate; coxae with dark, erect setae and lighter, shorter decumbent setae; femora with short, appressed setae and microtrichia; mid tibial organ absent; tibial spur formula 1:2:2; tibiae with short, appressed setulae and short, erect setae that are no longer than half widest width of tibia; tarsal claws small; empodium developed.

Abdomen with segments of subequal width; sternites with two longitudinal fold lines along length; in male, segments 8 modified so that genitalia orient upwards. Male terminalia with enlarged, hood-like epandrial sclerite (tergite IX); cerci and epiproct reduced; hypoproct with lightly sclerotized anterior apodemes; gonocoxites widely separated, joined by narrow medial bridge; gonostyli simple, without subtending appendages, inwardly-directed, and arising from middle area of gonocoxites. Female terminalia with first cerci elongate, second cerci ovoid, sternite 8 clearly larger than tergite 8.

Etymology.

The genus name is feminine, derived from the English “sprite” and the Latin ending “-ella”, as a diminutive.