Winnertzia brachytarsus, Jaschhof & Jaschhof, 2020

Jaschhof, Mathias & Jaschhof, Catrin, 2020, Reevaluation of species richness in Winnertzia (Diptera, Cecidomyiidae, Winnertziinae), with descriptions of 37 new species from Sweden, Peru and Australia, Zootaxa 4829 (1), pp. 1-72 : 12

Winnertzia brachytarsus sp. nov.

Figs 7–9

Diagnosis. A small, brown Winnertzia with short antennae and short palpi. The fore tarsus of W. brachytarsus is appreciably shorter than in other species of the discreta group, the second tarsomere being only about half as long as the tibia. Male genitalic characters specific to this species are as follows ( Fig. 9 ). The elongate, subcylindrical gonostylus is covered with dense, moderately long microtrichia apicomedially (↓ 1); of the gonocoxites, the ventral emargination is perfectly U-shaped, the ventroposterior portions form broadly rounded lobes (↓ 2) that extend beyond the dorsoposterior portions, and the dorsal apodemes are short; the tegmen has large flaps with marginal microtrichia (↓ 3); and the posterior edge of the ninth tergite is indented medially. Winnertzia brachytarsus is known from the holotype male only; females and preimaginal stages are unknown.

Other male characters. Body size 1.3 mm. Head. Eye bridge 2–3 ommatidia long dorsally. Antenna shorter than half body. Scape and pedicel same size, both concolorous with flagellum. 10 flagellomeres, apical flagellomere long, translucent sensilla present on all flagellomeres. Fourth flagellomere: neck 0.3 times as long as node; node 1.5 times as long as broad; sensory hairs numerous; both lateral and medial translucent sensilla long, filiform to slightly broadened ( Figs 7–8 ). Palpus clearly shorter than head height, 4 setae-bearing segments; second to fourth segment equally long. Labella fully developed, albeit small. Thorax. Pronotal setae 2. Anepimeral setae absent. Lateral mediotergal microtrichia conspicuously large. Parascutellar area bright, vaguely contoured. Wing shorter than body, 2.3 times as long as broad. Costal cell reinforced. M 4 faint, CuA gently bent, both veins extending to edge of wing. Legs. Scales pointed. Basitarsal spines absent. Acropods: claws slightly bent, toothless; empodia vestigial.

Abdomen. Pleural membrane devoid of setae. Genitalia ( Fig. 9 ). Ninth tergite shorter than half gonopodal length; setae confined to posterior portion; anterior edge straight, indistinct. Gonocoxal synsclerite slightly broader than long; ventral emargination membranous basally; ventroanterior edge slightly convex; dorsal apodemes shorter than half the distance separating them. Gonostylus 2.5 times as long as broad, nearly parallel-sided, straight; basolateral apophysis small, angulated. Aedeagal apodeme parallel-sided; apex slightly narrowed; solid basal portion short. Aedeagal bulge with closely spaced rows of tiny spikes. Tegmen sharply contoured, markedly tapered towards rounded apex; parameral apodemes small.

Etymology. The name, a noun in apposition, refers to the unusually short tarsi of this species.

Type material. Holotype. Male , Sweden, Småland , Nybro , Bäckebo , Grytsjön Nature Reserve, old-growth forest of conifers mixed with aspen trees, 2–12 July 2005, Malaise trap, Swedish Malaise Trap Project (trap 1000, collection event 1323) (spn CEC 1882 in NHRS).

Distribution and phenology. The only specimen available of W. brachytarsus was collected at the height of summer in a mixed, old-growth hemiboreal forest in Småland, southern Sweden. Our studies over the past 15 years have shown the collecting site, Grytsjön Nature Reserve, to be a hotspot of Winnertzia diversity, with 30 species found there. In spite of the fact that we continued Malaise trapping in Grytsjön in several of the subsequent years, we failed to capture another specimen of W. brachytarsus .

Figures

FIGURES 7–13. Male morphology of Winnertzia brachytarsus (7–9) and Winnertzia imbecilla (10–13), holotypes. 7: Fourth flagellomere, lateral. 8: Ditto, medial. 9: Genitalia, ventral. 10: Genitalia, ventral. 11: Palpus, lateral. 12: Fourth flagellomere, lateral. 13: Ditto, medial. Scales for 7–10 and 12–13, 0.05 mm; for 11, 0.025 mm. Arrows refer to characters described in the diagnoses.