Macrurohelea ventanensis, Spinelli & Ronderos & Grogan, 2022

Spinelli, Gustavo R., Ronderos, Maria M. & Grogan, William L., 2022, Five new species in the predaceous midge genus Macrurohelea Ingram & Macfie from Argentina, and descriptions of the previously unknown males of M. kuscheli Wirth and M. monotheca Spinelli & Grogan (Diptera: Ceratopogonidae), Zootaxa 5093 (4), pp. 445-464 : 458-462

Macrurohelea ventanensis n. sp.

( Figs. 33–36 , 49–50 )

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Diagnosis. Males: the only species with a pale brown halter; tergite 9 abruptly tapered on basal 1/5, with rounded apex; tergite 10 with straight margins, apex straight with small, rounded apicolateral process with single divergent seta; parameres stout, nearly straight, widely separated, subparallel, with slender, slightly hooked, curved, fingerlike apical process; aedeagus basal arch deeply concave, heavily sclerotized, distal portion more lightly sclerotized, apex with a short hyaline quadrate process. Females unknown.

Male. Head ( Fig. 33 ) brown. Eyes separated medially by width of 2.5 ommatidia with numerous short interommatidial spicules. Antennal flagellomeres distinctly separated; flagellomeres 1–8 broadly moniliform, 9–10 narrow, slightly elongate, 11–13 more elongate, 13 longest. Palpus brown; segment 3 with small sensory pit slightly distad of mid-length; segment 4 0.66 length of segment 3, segment 5 slightly longer than segment 3, with bulbous apex; palpal ratio 2.00–2.50 (2.25, n =2). Thorax ( Fig. 34 ) uniformly dark brown; scutum with 3 stout prealar setae, one postalar seta; scutellum with 4 stout, long setae. Legs medium brown; femora, tibiae very slender, greatly elongate; ventral palisade setae on tarsomere 1 of fore, hind legs; tarsomeres 4 cordiform; tarsal claws small, mostly straight, slightly curved on extreme bifid tips. Wing ( Fig. 35 ) membrane pale, slightly infuscated with minute microtrichia; anterior veins yellowish brown, posterior veins paler; 2 nd radial cell twice as long as 1st; cell r 3 with poorly developed intercalary vein; r-m crossvein slightly shorter than petiole of M; medium-size macrotrichiae on costa; wing length 1.31–1.35 (1.33, n =2) mm, width 0.45–0.47 (0.46, n = 2) mm; costal ratio 0.59–0.63 (0.61, n =2); halter pale brown. Abdomen brown. Genitalia ( Figs. 36 , 49–50 ). Tergite 9 abruptly tapered on basal 1/5, distal portion broad, elongate with rounded apex, extending 0.75 length of gonocoxites. Tergite 10 with straight margins, apex straight with small rounded divergent apicolateral process with single medium-size seta; cercus slender, fingerlike. Sternite 9 2.4x broader than long, posteromedian margin with shallow excavation. Gonocoxite stout, twice as long as wide, with rounded sub-basal mesal extension; gonostylus 0.77 length of gonocoxite, proximal ¼ broadest, distal ¾ greatly curved with pointed apex. Parameres ( Fig. 49 ) broadly separated, heavily sclerotized; basal apodeme stout, laterally directed, apex blunt; distal halves stout, nearly straight, sub-parallel, with slender, slightly hooked, apical, curved finger-like process.Aedeagus ( Fig. 50 ) broadly triangular, 0.80 length of basal width; basal arm stout, laterally directed with curved truncate tip; basal arch deeply concave, heavily sclerotized, extending nearly 2/3 of total length; distal portion lightly sclerotized, tapered distally, with a short, apical hyaline quadrate process.

Female. Unknown.

Type material. Holotype male, paratype male, labeled “ Macrurohelea ventanensis Spinelli, Ronderos and Grogan ”, “ Argentina, Buenos Aires, Reserva Parque Prov. Ernesto Torquinst, arroyo Ventana , 38º03’31.7’’S, 62º01’11.8’’W, 574 m, XI/2012, A. Siri – M. Donato, Malaise trap.

Distribution. Argentina, known only from the type-locality in southern Buenos Aires province.

Derivation of specific epithet. The specific epithet is in reference to Sierra de la Ventana, where the type-series was collected.

Discussion. Males of this new species are similar to those of M. kuscheli . However, in M. kuscheli flagellomeres 4–9 are fused, and the aedeagus is slightly triangular with the distal portion slender, bifid, with short, separated tips.

Figures

FIGURES 33–36. Macrurohelea ventanensis n. sp. Holotype male. 33 head. 34 thorax. 35 wing. 36 genitalia. Scale bars = 0.05 mm.

FIGURES 47–50. Macrurohelea sirii n. sp. Holotype male, 47–48. Macrurohelea ventanensis n. sp. Holotype male, 49–50. 47, 49 parameres. 48, 50 aedeagus.