Macrurohelea kuscheli Wirth, 1965

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 : 452-454

Macrurohelea kuscheli Wirth

( Figs. 15–18 , 41–42 )

Macrurohelea kuscheli Wirth, 1965: 49 (female; Chile); Wirth 1974: 39 (in New World catalogue south of the USA); Spinelli & Grogan 1984: 962 (in key); Spinelli & Grogan 1990: 132 (in key); Borkent & Wirth 1997: 100 (in World catalogue); Borkent & Spinelli 2000: 49 (in New World catalogue south of the USA); Borkent & Spinelli 2007: 82 (in Neotropical catalogue); Spinelli & Marino 2009: 205 (in list of Ceratopogonidae of Patagonia); Borkent & Dominiak 2020: 164 (in World catalogue).

Diagnosis. Females: the only species with flagellomeres 2–8 very short, moniliform, 9–12 slightly broader than long, 13 longest, twice as long as 12; thorax and legs dark brown; wing membrane pale grayish, without intercalary vein in cell r 3, costal ratio 0.68; halter brownish; two ovoid, subequal-size spermathecae without sclerotized necks and a 3 rd very small spermatheca. Males: the only species with flagellomeres 4–9 fused, more or less globular, 11–13 separate, more elongate; parameres with distal portion slender, nearly straight, with elongate, hooked, slender distal process; aedeagus slightly triangular, with distal portion slender, bifid, tips short, separated.

Male. Head ( Fig. 15 ) dark brown. Eyes separated medially by width of 3 ommatidia, with numerous short interommatidial spicules. Antennal flagellum short, with flagellomeres 4–9 fused, more or less globular, 10–13 separate, more elongate; antennal ratio 0.44–0.52 (0.49, n=6). Palpus pale brown; segment 3 with very shallow sensory pit at distal 1/3; segment 4 very short, segment 5 slightly longer than segment 3; palpal ratio 1.62–2.22 (1.96, n=5). Thorax ( Fig. 16 ) uniformly dark brown; scutum with 4 stout prealar setae, one postalar seta; scutellum with 3 stout, long setae and 3 slender, shorter setae. Legs dark brown; ventral palisade setae on tarsomere 1 of fore, hind legs; tarsomeres 4 cordiform; tarsal claws very short, mostly straight with bifid tips. Wing ( Fig. 17 ) membrane hyaline with minute microtrichia, veins pale gray; second radial cell 0.95–1.76 (1.25, n=6)x longer than first; cell r 3 without intercalary vein; M 2 barely perceptible, but apparently r-m crossvein as long as petiole of M; medium-size macrotrichiae on costa; wing length 0.80–0.89 (0.84, n=6) mm, width 0.32–0.34 (0.33, n=6) mm; costal ratio 0.61– 0.65 (0.62, n=6). Halter brown.Abdomen ( Fig. 16 ) dark brown. Genitalia ( Figs. 18 , 41–42 ). Tergite 9 semi-triangular with blunt tip, extending 0.6 length of gonocoxites. Tergite 10 quadrate, posterior margin straight, apicolateral process elongate, tip slightly bifid with slender mesal seta; cercus slender, elongate, finger-like. Sternite 9 3x broader than long, posteromedian margin nearly straight. Gonocoxite stout, 1.4x longer than wide, with stout, antero-mesal tubercle; gonostylus 0.8 length of gonocoxite, slender, curved on distal 1/2, tip pointed. Parameres ( Fig.41 ) separate; basal apodeme slender, laterally directed, anterior margin with short tubercle, distal portion slender, nearly straight, with elongate, hooked, slender distal process. Aedeagus ( Fig. 42 ) slightly triangular, 0.60x longer than basal width; basal arch lightly sclerotized, extending 0.40 of total length; distal portion slender, bifid, heavily sclerotized, tips short, separated.

Holotype Female. Chile, Valparaiso, Algarrobo , 18- IX/1951, G. Kuschel ( USNM, examined in 1983 by GRS).

New records. Argentina, Río Negro, PN Nahuel Huapi, río Manso medio, La Cantera , 41°21’16’’S, 71°42’27.3’’W, 764 m, 11-XII-2006 / 15-I-2007, A. Garré – F. Montes de Oca, 1 female, Malaise trap ( MLPA) ; same data except 11/ 30-XII-2007, 1 male, 3 females ; same data except 10-XI-2008 / 1-XII-2008, 1 male ; Río Negro, PN Nahuel Huapi, arroyo Vertiente , 41°36’5.8’’S, 71°36’24.8’’W, 468 m, 10-XI-2008 / 1-XII-2008, A. Garré – F. Montes de Oca, 4 males, 3 females, Malaise trap ( MLPA) . Chile, Arauco, Pata de Gallina , 7-XII-2003, G. Spinelli, aerial net, 1 male ( MLPA) .

Distribution. Chile and Argentina (western Río Negro province).

Discussion. The males described herein were collected associated with females and they exhibit common features with females, such as their small size, short flagellum, palpal segment 3 with very shallow sensory pit, wing membrane hyaline with minute microtrichia, veins pale gray, cell r 3 without intercalary vein, vein M 2 barely perceptible, r-m crossvein as long as petiole of M, and brown halter. Males of M. kuscheli are readily distingished from other Neotropical congeners by their fused flagellomeres 4–9. The genitalia of M. kuscheli is similar to M. ventanensis n. sp., but in that species the aedeagus is broadly triangular, with deeply concave basal arch and distal portion tapered distally, with short, apical hyaline quadrate process. In an apparent lapsus, Wirth (1965) noted for females “second radial cell 0.5 as long as second.” However, he meant to say the 1st radial cell was about half the length of the 2 nd radial cell.

Figures

FIGURES 15–21. Macrurohelea kuscheli Wirth, male, 15–18. Macrurohelea monotheca Spinelli & Grogan, male, 19–21. 15, 19 head. 16 thorax. 17, 20 wing. 18-21 genitalia. Scale bars = 0.05 mm.

FIGURES 37–42. Macrurohelea bassoi n. sp. Holotype male, 37–38. Macrurohelea donatoi n. sp. Holotype male, 39–40. Macrurohelea kuscheli Wirth, male, 41–42. 37, 39, 41 parameres. 38, 40, 42 aedeagus.