Metajalysus horvathi Štusák, 1977

Henry, Thomas J. & Dellapé, Pablo M., 2021, Revision of the Neotropical Stilt Bug Genus Metajalysus Štusák (Hemiptera Heteroptera: Berytidae), with Descriptions of Three New Species, Zootaxa 4958 (1), pp. 690-701 : 695-696

Metajalysus horvathi Štusák

http://lsid.speciesfile.org/urn:lsid: Lygaeoidea .speciesfile.org:TaxonName:479891

( Figs. 7–9 , 15 , 24–27 )

Metajalysus horvathi Štusák, 1977: 422 (original description); Henry 1997a: 61 (list), 1997b: 49 (in part, description, distribution); Henry & Froeschner 1998: 25 (catalog); Henry 2002: 189 (in part, distribution); Dellapé 2014: 437 (list); Dellapé & Henry 2020 (online catalog).

Diagnosis. Metajalysus horvathi ( Figs. 7–9 ) is distinguished by the black head, except for the yellow middle and lateral carinae; the black ventral areas of the thorax and abdomen; the short setae on the femora and pro- and mesotibiae that are subequal to the diameter of the segments; and the nearly flat ventral margin of the male genital aperture ( Figs. 24–26 ).

It is most similar to M. pilosus , n. sp. ( Figs. 10–12 ) in having a black head and largely black thorax, with extensive black areas on the abdomen, but M. pilosus has longer erect setae on the femora and pro- and mesotibiae that are one and a half to two or more times the diameters of the segment, a distinct inverted V-shaped process on the middle ventral margin of the male genital aperture, and the more slender decurved arm of the parameres ( Fig. 31 ).

We note that a few specimens of what we consider M. horvathi have longer, erect setae on the femora more similar to M. pilosus ; however, the nearly flat ventral margin of the genital capsule is consistent with specimens having more typically short setae, which is unlike the distinct inverted V-shaped process in M. pilosus .

Description. Male (n = 3): Length 3.68–4.00 mm, width 0.88–0.96 mm. Head: Length 0.46–0.50 mm, width across eyes 0.38–0.40 mm, interocular width 0.24–0.27 mm. Labium: Length 1.26–1.33 mm. Antenna: Scape length 2.18–2.27 mm; pedicel, 0.70–0.77 mm; basiflagellomere, 1.47–1.63 mm; distiflagellomere, 0.61–0.64 mm. Pronotum: Median length 0.67–0.78 mm, posterior width 0.67–0.69 mm. Femoral lengths: Pro- 1.41–1.50 mm, meso- 1.66–1.70 mm, meta- 2.46–2.53 mm. Tibial lengths: Pro- 1.63–1.79 mm, meso- 2.11–2.18 mm, meta- 3.36–3.52 mm.

General color yellowish brown to brown, with black areas. Head: Uniformly black, except for the yellow lateral and middle (when present) carinae; each lateral carina with one long and one short seta, middle carina or midline with a row of erect setae; eyes and ocelli reddish brown. Labium: Brown to yellowish brown, basal half of segment I dark brown, extending to base of metasternum. Antenna: Yellowish brown, scape with widely spaced setae equal to or slightly greater than diameter of segment; pedicel and basiflagellomere with more dense, short setae no longer than diameters of segments; distiflagellomere black, with apex dark yellowish brown. Pronotum ( Fig. 15 ): Yellowish brown, calli darker brown, anterolateral angle and lateral margin along carina black, median carina yellow; each side of disc with 6 or 8 erect setae, point of each posterior tubercle with 2 or 3 setae. Scutellum: Yellowish brown, raised tubercle yellow. Hemelytron: Translucent; veins brown to dark brown, with a slender rectangular brown spot on either side of middle; membrane with brown blotches between veins. Ventral surface: Thorax shiny black; basal three quarters of abdomen black, apical third and genital capsule yellow to yellowish brown, with scattered pale setae. Ostiolar evaporative area: Uniformly yellow. Legs: Coxae brown to dark brown, apices paler; femora yellowish brown, hind femur sometimes darker at base and apex, with only short scattered setae subequal to diameter of segments; tibiae yellowish brown, with only short setae subequal to diameter of segments.

Male genitalia: Genital capsule ( Figs. 24–26 ) with middle ventral margin of aperture nearly flat. Parameres ( Fig. 27 ) with smaller hind arm elongate, curved, and directed upward.

Female (n = 5): Length 4.08–4.52 mm, width 0.98–1.12 mm. Head: Length 0.45–0.50 mm, width across eyes 0.42–0.45 mm, interocular width 0.29–0.30 mm. Labium: Length 1.33–1.36 mm. Antenna: Scape length 2.05–2.30 mm; pedicel, 0.67–0.74 mm; basiflagellomere, 1.44–1.60 mm; distiflagellomere, 0.61–0.67 mm. Pronotum: Median length 0.77–0.80 mm, posterior width 0.72–0.83 mm. Femoral lengths: Pro- 1.41–1.54 mm, meso- 1.66–1.82 mm, meta- 2.43–2.72 mm. Tibial lengths: Pro- 1.60–1.76 mm, meso- 2.02–2.27 mm, meta- 3.30–3.68 mm.

Similar to male in general color, texture, and vestiture.

Hosts. Adults taken on Cucumis sp. [ Cucurbitaceae ] and Salpichroa oranifolia (Lam.) Baill. [ Solanaceae ].

Distribution. Known only from Argentina. Described from Tucumán Province ( Štusák 1977). Later recorded from Salta and Catamarca provinces ( Henry 1997b, 2002). Jujuy Province is a new record.

Type material examined. The holotype female from “ Argentina, Tucuman, 1906, leg. Vezényi” apparently never was returned to the HNHM and is presumed lost. Although Štusák (1977) indicated that it was to be deposited in the Hungarian Museum of Natural History, it never was returned to that collection (Péter Kóbor, pers. comm.). Subsequent efforts to communicate with Stusak’s family about his collection were unsuccessful. Consequently, to ensure nomenclatural stability, we are designating the following male deposited in the MLP as a neotype for M. horvathi: Label 1, “ Salta Prov., Prov. Rd. 9, 9.4 km SE onto Prov. Rd. 11, 1375 m, 24º40.412’S, 65º21.622’W, 17 Feb. 2016, T. J. Henry & P. M. Dellapé, ex Cucumis sp.”; 2 [red printed label], Neotype ♂, Metajalysus horvathi Štusák , by T.J. Henry & P.M. Dellapé” ( MLP).

Other specimens examined. ARGENTINA: 1♂, Catamarca, Santa Maria , 14 Oct. 1972, G. E. Bohart ( USNM) . 1♂, Jujuy, R.P. 20, camino a Las Capillas , N de Palpalá, 24° 11.704´S 65° 14.283´W, 15 Feb 2016, T. J. Henry & P. M. Dellapé ( MLP) . 1♀, Salta, San Lorenzo , 8 Jan. 1951, P. Wygodzinsky ( USNM) ; 4 ♂♂, 8♀♀, Salta Prov., Prov. Rd. 9, 9.4 km SE onto Prov. Rd. 11, 1375 m, 24º40.412’S, 65º21.622’W, 17 Feb. 2016, T. J. Henry & P. M. Dellapé, ex Cucumis sp. ( USNM) ; 3 ♂♂, Salta Prov., San Lorenzo, Hotel Selva Montana , 24°43.587´S 65°29.858´W, 3 Feb. 2016, T. J. Henry & P. M. Dellapé ( MLP) ; 3♂♂, 3♀♀, Salta Prov., El Alisal, I-1990, D. L. Carpintero ( MLP) ; 2♂♂, 2♀♀, Salta Prov., San Lorenzo, Reserva Municipal Yungas de San Lorenzo , 24º43.86’S, 65º30.148’W, 3 Feb. 2016, T. J. Henry & P. M. Dellapé, ex Salpichroa organifolia (USNM) .

Discussion. Štusák’s (1977) excellent illustrations and description of M. horvathi as having a black head and the setae on the femora and tibia (except for the hind tibiae) only as long as the diameter of the respective segments allow us to confidently recognize it among the material we have accumulated and to designate the neotype above.

Consequently, we also have determined that Henry (1997b), who had a limited amount of material, based his redescription of M. horvathi on a mixture of at least three species, including M. graziae , n. sp., M. horvathi , and M. pilosus , n. sp. The female he listed from San Lorenzo, Salta, Argentina (P. Wygodzinsky) is M. horvathi . Another specimen from that locality, as well as one male and one female from Angostura de Arias, Salta, Argentina (Herrera) [mislabeled on specimen label as Brazil], are M. graziae , n. sp. The three females from Belen, Tarapacá, Chile (L. E. Peña) are near M. clavatus , n. sp. (see M. clavatus ). We were unable to locate the other specimens listed in Henry’s (1997b) paper. The specimens recorded as M. horvathi from Ecuador in Henry (2002) are M. pilosus , n. sp., and the host plants mentioned refer to that species.

Figures

FIGURES 7–12. Metajalysus spp. 7, M. horvathi, male dorsal aspect. 8, M. horvathi, male, lateral aspect. 9, M. horvathi, female, dorsal aspect. 10, M. pilosus, n. sp., male dorsal aspect. 11, M. pilosus male lateral aspect. 12, M. pilosus, female, dorsal aspect. Scale bar for plate = 1 mm.

FIGURES 13–16. Metajalysus spp. pronota, frontal views. 13, M. clavatus, n. sp. 14, M. graziae n. sp. 15, M. horvathi. 16, M. pilosus, n. sp.

FIGURES 17–31. Male genitalia of Metajalysus spp. M. clavatus, n. sp.: 17–20. 17, genital capsule, caudal aspect, in situ. 18, genital capsule, caudal aspect, cleared. 19, genital capsule, dorsal aspect, cleared. 20, left and right parameres. M. graziae, n. sp.: 21–23. 21, genital capsule, caudal aspect, in situ. 22, genital capsule, caudal aspect, cleared. 23, left and right parameres. M. horvathi: 24–27. 24, genital capsule, caudal aspect, in situ. 25, genital capsule, caudal aspect, cleared. 26, genital capsule, dorsal aspect, cleared. 27, left and right parameres. M. pilosus, n. sp.: 28–31. 28, genital capsule, caudal aspect, in situ. 29, genital capsule, caudal aspect, cleared. 30, genital capsule, dorsal aspect, cleared. 31, left and right parameres.