Stilobezzia (Stilobezzia) tobiasi Huerta & Grogan, 2021

Huerta, Heron & Grogan Jr, William L., 2021, A new species of predaceous midge in the genus Stilobezzia Kieffer from Mexico (Diptera: Ceratopogonidae), Zootaxa 4908 (2), pp. 297-300 : 297-298

Stilobezzia (Stilobezzia) tobiasi Huerta & Grogan n. sp. ( Figs. 1–16 )

Stilobezzia (Stilobezzia) femoralis Lane & Forattini, 1956: 212 . Huerta, 2002: 57 (male, female diagnosis; in key; figs.; Mexico record); Borkent & Spinelli, 2007: 87 (in Neotropical catalog; Mexico (Yucatan), Panama); Huerta & Grogan, 2017: 407 (in key to Stilobezzia of Mexico).

Diagnosis. The only Neotropical species of Stilobezzia (S.) with the following combination of characters. Males with dark brown thorax; fore coxa pale brown, mid and hind coxae dark brown; fore femur and tibia yellowish; mid femur dark brown on proximal 2/3, distal 1/3 yellowish, mid tibia yellowish with a narrow dark brown basal band; hind femur dark brown with yellow subapical band, hind tibia yellowish with narrow dark brown apical band; and gonocoxite with a pair of mesally directed finger-like lobes. Females with similar coloration of males; claws slightly shorter than their respective tarsomeres 5, mid claws longer than fore claws, fore claws longer than hind claws; and one ovoid spermatheca with short neck.

Male. Head ( Fig. 1 ) pale yellow. Eyes narrowly separated, without interommatidial spicules. Antennal scape, pedicel ( Fig. 2 ) yellowish; flagellomeres 1–10 brown, 11–13 pale brown; flagellomeres separated, 11–13 elongated; plume dense, dark brown; antennal ratio 1.06–1.08 (1.07; n=2). Mouthparts short, light brown. Palpus pale brown; segment 3 cylindrical, with capitate sensilla on subapical mesal surface; segment 4 short; segment 5 darker, slightly shorter than segment 3; palpal ratio 4.0–4.8 (4.5; n=3). Clypeus rhomboid with 3 pairs of long, thin submarginal setae. Thorax ( Fig. 6 ). Dark brown; scutellum glossy with 2 marginal, 2 central long setae. Paratergite without seta, with lateral suture; anepisternum well developed, not bilobed posteriorly; pleura dark brown, without setae. Legs ( Fig. 6 ). Fore coxa pale brown, mid and hind coxae dark brown; fore femur, tibia yellowish; mid femur dark brown on basal two thirds (ca 0.72 of total length), extreme narrow base and apical 1/3 yellowish, tibia with a narrow faint pale brown band, remainder yellowish; hind femur dark brown, with very narrow basal and subapical yellowish band, apex dark brown, tibia yellowish with dark brown apical band; tarsi of all legs pale yellow; tarsomeres 1–2 of fore, mid legs with one row, 1–2 of hind leg with two rows of ventral palisade setae; claws small, equal-sized; hind tibial comb with 8 spines; prothoracic TR 2.09–2.45 (2.32, n=3); mesothoracic TR 2.61–3.09 (2.84, n=3); metathoracic TR 1.91–2.27 (2.06, n=3). Wing ( Fig. 11 ) membrane hyaline, with fine microtrichia; anterior veins pale brown; 1st radial cell very small, 2nd radial cell 4.2X longer than 1st; M forking at level of distal ½ of 2 nd radial cell; cubital fork at level of base of 2 nd radial cell; wing length 1.20–1.32 (1.26, n=4) mm, width 0.36–0.38 (0.37; n= 4) mm; costal ratio 0.67–0.68 (0.68; n=4). Halter dark brown. Abdomen ( Fig. 13 ). Tergites dark brown; tergite 1 posterior margin with narrow sclerotized distal band; sternites pale brown. Genitalia ( Figs. 14‒16 ). Tergite 9 longer than broad, anterior, posterior margins straight (very short, with medial cleft in 1 paratype); sternite 9 3.5X broader than long, posterior margin slightly curved, membrane spiculate; sternite 10 spiculate, cerci short, setose. Gonocoxite stout, twice as long as broad, with a pair of finger-like lobes mesally directed. Gonostylus 0.66 length of gonocoxite, curved, base stout, with slender sharply pointed tip. Parameres large, heavily sclerotized; basal apodeme stout, laterally curved, sub-basally joined by a narrow, sclerotized band; main stems straight, becoming more widely separated posteriorly, apices tapered, bent 90º laterally, tips sharply pointed. Aedeagus composed of a pair of long, straight, heavily sclerotized bars that are connected to the base of the gonocoxite, but, they are more anteriorly situated than the parameres.

Female. Similar to male with the following notable sexual differences. Antennal flagellomeres dark brown ( Fig. 3 ), except basal 2/3 of 1–8 pale yellow; antennal ratio 1.1 (n=1). Palpus ( Fig. 4 ) dark brown; palpal ratio 3.0 (n=2). Mandible ( Fig. 5 ) with 6 large, coarse medial teeth. Thorax ( Fig. 7 ). Scutellum with 6 large setae. Legs similar to male; mid tibia yellowish with narrow dark brown basal band and very narrow dark brown apical band; hind tibial comb with 7 spines; prothoracic TR 2.4 (n=2); mesothoracic TR 2.7 (n=2); metathoracic TR 2.1 (n=2); tarsomeres 5 of all legs ( Figs. 8–10 ) with a pair of sub-basal, blunt spines; claws slightly shorter than their respective tarsomeres 5, with smaller inner claw; mid claws longer than fore claws, fore claws longer than hind claws. Wing ( Fig. 12 ) membrane light brown, without brown spot; vein M 1+2 4.7X the length of r-m crossvein; 2 nd radial cell 4.5X longer than 1 st; wing length 1.30–1.31 (1.30, n=2) mm, width 0.48–0.50 (0.49, n=2) mm; CR= 0.71 (n=2). Abdomen. Tergites shining black; tergite 1 with anterior margin not sclerotized, V-shaped, white; sternites shining dark brown. Sternite 8 not in position to describe. One ovoid spermatheca, 0.09 by 0.05 mm, with short neck.

Type material. HOLOTYPE Male. MEXICO: Yucatan, Reserva Natural de Ria Lagartos: Km 10 carretera Ria Lagartos-Las Coloradas , al este de la estación Ria Lagartos , vegetacion Peten “Tucha”. GPS: [21° 35´46´´ N; 88° 08´47´´W], 8–Jul–1996, Malaise trap, Cols. Paz-Rodriguez, R. & Huerta, H., on slide. Colección de Artrópodos con Impor- tancia Médica ( CAIM), Mexico City . ALLOTYPE Female: same data as holotype except, 15-Oct-1996, on pin. PARATYPES: same data as holotype except 30-Nov-1995, light trap, on pin, 1 female; Tizimin, entrada a Zacbo, 4.2 km al sur de la estacion “El Cuyo”, GPS: [21° 28´58´´ N; 87° 42´2´´W], selva baja, light trap, 1-Apr-1997, Cols. Ibáñez-Bernal, S, Manrique-Saide, P., 1 male; Estación Ria Lagartos, entronque sobre las carreteras Las Coloradas-San Felipe, GPS: [21° 34´17´´ N; 88° 09´38´´W], light trap, 31-Aug-1995, Col. Huerta, H, 1 female. Reserva Natural de Ria Celestún: Rancho Loma Bonita, Km 15 carretera Celestún-Kinchil, sobre terraceria, vegetacion Peten, GPS: [20° 50´56´´ N, 90° 15´40´´ W], 5-Sep-1995, CDC trap, Cols. Navarro-Correa, C, Manrique-Saide, P., Paz-Rodriguez, R., 1 male; Ecoparaiso, Km 12 carretera Celestun-Sisal, 12 km al noroeste de Celestun, duna costera, GPS: [20° 58´38´´ N, 90° 21´18´´ W], Malaise trap, 17-Jul-1996, Cols. Navarro-Correa, C., Paz-Rodriguez, R., 1 male; Dumac, 1 km al este de Celestun, carretera Celestun-Kinchil, mangle, GPS: [20° 51´30´´ N, 90° 23´0´´ W], 3-Jul-1997, light trap, Cols. Manrique-Saide, P., Paz-Rodriguez, R., Huerta, H. 1 male. Morelos: Puente de Ixtla , San Jose Vista Hermosa , sobre la calle Josefa Ortiz de Dominguez , sitio “La Cañada”, 4-Aug to 3-Sep 2013, Malaise trap, Col. Sergio Hernandez-Tobias, 1 male .

Discussion. This new Mexican species is distinguished from other Neotropical Stilobezzia (Stilobezzia) by its mid femur that is dark brown on basal 2/3 and the apical 1/3 is yellowish, mid tibia yellowish with narrow dark brown basal band and very narrow dark brown apical band; hind femur dark brown with yellow subapical band and dark brown apex; and male gonocoxite with a pair of finger-like lobes mesally directed.

In the similar Nearctic and Neotropical Stilobezzia (S.) antennalis (Coquillett) , their mid and hind femora are also black, but their fore femur and all tibiae are yellow; the male parameres are sinuate and their apices are curved inwardly, the gonocoxite with a large irregular basal lobe, the aedeagus is much shorter and broader basally; and, females have two spermathecae, but, the much smaller 2 nd spermatheca is round. In males S. (S.) femoralis Lane & Forattini (1956) , the mid femur is only brown on the basal 2/3, but the distal 1/3 is yellow; the gonocoxite is slender with only a small short, inner triangular lobe on the distal 2/3; the gonostylus is much shorter; and the wing is much longer (length 2.0 mm); however, females are unknown. In S. (S). wygodzinskyi Lane (1947) , the proximal 2/3 of the mid tibia and femora are dark brown, but, their distal 1/3 are yellow, however, males are unknown ( Lane & Forattini 1961). In S. (S). chaconi Macfie (1938) , the mid tibia and mid and hind femora are entirely dark brown; the gonocoxite is slender with a small short, inner triangular lobe on its distal 1/3 and it also has a sharp seta-like medial lobe.

Etymology. This species is named after Sergio Hernández-Tobias for his collaboration during the collection of the specimens from Morelos and for sharing his experience with the identification of parasites of birds transmitted by species of Culicoides .

Figures

FIGURES 1‒16. Stilobezzia (Stilobezzia) tobiasi n. sp. Male: 1‒2, 6, 11, 13‒16; Female: 3‒5, 7‒10, 12. 1. Head, dorsal view; 2‒3. Antenna, lateral view; 4. Palpus, lateral view; 5. Mandible, lateral view; 6‒7. Thorax, lateral view; 8‒10. Tarsomere 5, lateral view, 8, fore leg, 9, mid leg, 10, hind leg; 11‒12. Wing, dorsal view, 11, anterior veins; 13. Abdomen, dorsal view. 14‒16. Male genitalia, ventral view. Scales: 1‒5, 8‒15 = 0.1 mm; 6‒7 = 0.5 mm; 16 = 0.4 mm. Abbreviations: aed= aedeagus; bas apo= basal apodeme; goncx= gonocoxite; gonst= gonostylus; lob = finger-like lobe of the gonocoxite; par= paramere; st 9= sternite 9.