Brontostoma infensum Wygodzinsky, 1951

Gil-Santana, Hélcio R., 2020, New synonymies among species of Brontostoma (Hemiptera: Heteroptera: Reduviidae), Zootaxa 4869 (3), pp. 301-325 : 319-323

Brontostoma infensum Wygodzinsky, 1951

( Figs. 71–83 )

Brontostoma infensum Wygodzinsky, 1951: 39 , 46, 47–48 (original description, figures).

Brontostoma infensum: Maldonado (1990: 29) (catalog), Dougherty (1995: 203) (citation, geographical distribution), Gil-Santana et al. (2004: 127,128) (citation, key), Gil-Santana et al. (2005: 78, 79) (citation, key), Gil-Santana et al. (2013: 62) (citation).

Distribution. Argentina, Peru?, Brazil? Diagnostic characters and their variability. Male. Body length 28–29 mm.

COLORATION ( Figs. 71 , 73–74 ): head; thorax (including scutellum and transverse furrow of pronotum, but excepting hind lobe of pronotum), and legs (except tarsi), generally blackish to dark brown. Base of neck yellowish ventrally; hind lobe of pronotum reddish; stridulitrum pale; hemelytra generally reddish with approximately distal half of clavus and adjacent area on corium blackish; vein between these dark areas also dark in the holotype, but pale reddish in the examined paratype; a longitudinal median dark spot on corium; membrane darkened, somewhat paler at its margins; connexivum reddish with dark markings present on segments II–VI, narrow, complete, reaching external margin; on segments III–VI, approximately equivalent to somewhat less than a third and a fifth of the length of each segment at the inner and outer portions, respectively. Tarsi yellowish. Sternites generally black brownish with irregular pale transverse markings, ill-defined in shape, restricted or mostly present in the distal portion of the segment (sternites III and IV) or running along almost all of the median portion of the segment (sternites V–VII); dark coloration at distal halves of sternites II–VI reaches lateral margin of each segment, resulting in separate pale reddish marginal spots ( Fig. 74 ).

STRUCTURE. Terminalia. Abdominal segment VIII similar to that of B. basalis . Male genitalia ( Figs. 77–83 ) generally similar to those of B. basalis . Genital capsule: paramere (pa) apices far from each other in resting position; medial process of pygophore (mpp) visible in ventral view ( Fig. 77 ). Dorsal phallotecal sclerite (dps) enlarged approximately at distal third, slightly sinuous in middle of anterior margin, laterally not sinuate, not folded at lateral margins ( Figs. 82–83 ). Upper half of the median portion of endosomal struts (es) with a thin medial longitudinal linear cleft (lc) with almost straight edges ( Fig. 83 ). After the endosoma quickly inflated spontaneously, basal portion of the external ventral layer (el) detached completely and its apical margin remained completely united to the apical portion of the endosoma ( Fig. 80 ); the most reasonable explanation to this observed condition is that there was a ventral fold, but for some reason the external ventral layer was pulled, torn and detached from its base. Because of the existence of a fold, the apex of the endosoma was in continuity with the apical portion of the ventral layer ( Fig. 80 ). Two endosoma processes: a basal large dense subtriangular process (stp); in the apex of the latter, the median process (mp) is attached by its midportion ( Figs. 80–81 ). The median process (mp) is flat, finely striated, faintly sclerotized, somewhat more at the mid portion; shaped as a pair of arched portions ( Fig. 81 ).

Type material examined. Brontostoma infensum Wygodzinsky, 1951 : Male holotype: [handwritten:] Brontostoma / infensum / Wygod. / [printed:] Wygodzinsky det. / INST. MED. REG. // [a handwritten label glued on a larger card:] Sa Maria / Urundel Salta / XII-47 // [a red printed label glued on a larger card, last letters not readable by the hole and the glue on it:] HOLO …[probably… TIPO] ( MACN). Male paratype: [handwritten:] Brontostoma / infensum / Wygodzinsky / [printed:] Wygodzinsky det. / INST. MED. REG. // [handwritten:] Urundel / Salta // [printed:] COLLECTIO / WYGODZINSKY // [handwritten red label:] PARATIPO ( MNRJ).

Discussion. Brontostoma infensum was described based on four males from the same locality, Urundel, Salta, in Argentina ( Wygodzinsky 1951). It was considered to be very similar to B. sanguinosum , from which it was supposed to be separated by the color differences stated in the aforementioned key. The total lengths of the type specimens were recorded as 28–29 mm ( Wygodzinsky 1951). The specimens examined here, the holotype ( Fig. 71 ) and a paratype ( Figs. 73–75 ) are very similar to each other and agree well with the original description. Subsequently, the species was recorded from Brazil and Peru by Dougherty (1995).

Because the general coloration of Brontostoma infensum is similar to many specimens of B. basalis , and the latter species is highly variable in color, it is not possible to separate the two species by the color differences suggested by Wygodzinsky (1951). The examination of the type materials and several additional specimens in course of this work showed that only the following color differences are of diagnostic value: 1– the distal portion of the clavus and the adjacent area of corium are pale (yellowish) in B. basalis and dark in B. infensum ; 2 – the membrane of the hemelytra is darker in B. infensum ; and most importantly, 3– the shape of the pale transverse markings of sternites III–VII are irregular and ill-defined in shape in B. infensum ( Fig. 74 ), but regularly bordered and symmetrical in B. basalis (e.g. Figs. 16 , 21 , 23, 25 , 29, 31, 33 ). Yet, in B. infensum , these pale markings are mostly present in the distal portion of sternites III and IV or run along almost all median portion of sternites V–VII ( Fig. 74 ) reaching the posterior margins of all these sternites, while in B. basalis , although variable in size, they do not reach the posterior margin of any segment, occupying approximately the basal portion of the sternites, as a pair of median pale markings in some segments (e.g. IV–VI; Figs. 21 , 23 ) to almost all of them (III–VII; Fig. 25 ) or as transverse bands variably narrower at midportion (e.g. Fig. 29 ).

In the examined type specimens of B. infensum the distal antennal segments were missing, therefore it was not possible to ascertain the coloration of all antennal segments. Wygodzinsky (1951) recorded that only the fifth antennal segment (first distiflagellomere) was yellowish, with the remaining segments black (the first) to piceous. On the other hand, in B. basalis the coloration of antennal distiflagellomeres were recorded as varying from grayish to whitish, with the last segment commonly somewhat pale grayish, sometimes only at its apex. An evaluation of the diagnostic value of this color character could only be possible based on an examination of more specimens of B. infensum , which could reveal whether in the latter species the yellowish color is always restricted to the first distiflagellomere or also occurs in other distiflagellomeres as in B. basalis .

As a conclusion, B. infensum is recognized as a distinct species differentiated from B. basalis based on the following set of diagnostic characters of their male genitalia: 1 – paramere apices in resting position: very close or in contact ( B. basalis ) ( Figs. 34, 38 ) or far from each other ( B. infensum ) ( Figs. 77–78 ); 2 – medial process of pygophore in ventral view: not visible ( B. basalis ) ( Figs. 34, 38 ) or visible between distant apices of parameres ( B. infensum ) ( Figs. 77–78 ); 3 – Dorsal phallothecal plate: enlarged to the apex, deeply sinuous in center of anterior margin and more pronounced sinuate laterally to anterior margin and with lateral margins forming a ventral curved fold (vf), with an acute apex (vfa), projecting laterally ( B. basalis ) ( Figs. 46 , 49 , 54, 56 ) or enlarged approximately at distal third, slightly sinuous in center of anterior margin, which laterally is not sinuate, and neither folded at lateral margins ( B. infensum ) ( Fig. 82 ); 4 – Upper half of median portion of endosomal struts with conspicuous medial sinuous longitudinal borders in B. basalis ( Fig. 56 ) or with a thin linear cleft whose edges are almost straight in B. infensum ( Fig. 83 ).

The fully spontaneously inflated endosoma of B. infensum ( Fig. 80 ) suggests that a ventral fold (evf) was present before the detachment of the external ventral layer (el). As a similar fold is present in B. basalis , it seems reasonable to suppose that these folds have no diagnostic value at species level in the taxa treated in this paper.

Dougherty (1995) recorded B. infensum from Argentina, Brazil and Peru. However, records from the latter two countries were based on non-type specimens identified based on their color and therefore they potentially represent misidentifications of B. basalis , and accordingly they are considered as in need of confirmation. It is noteworthy that B. basalis (including all its junior synonyms established here) has been recorded from several countries in South and even in Central America; B. infensum was recorded, aside from the doubtful records of Dougherty (1995), only from Argentina ( Wygodzinsky 1951); the latter species is possibly restricted to the southern part of South America.

Figures

FIGURES 71–72. Brontostoma infensum Wygodzinsky, 1951, male holotype. 71, dorsal view; 72, labels and a card pinned to the specimen with a fore and a hind tarsi glued.

FIGURES 73–76. Brontostoma infensum Wygodzinsky, 1951, male paratype. 73–74, scale bars 5.0 mm, 73, dorsal view, 74, ventral view; 75, apex of abdomen, ventral view, scale bar 2.0 mm; 76, labels.

FIGURES 77–83. Brontostoma infensum Wygodzinsky, 1951, male paratype, genitalia. 77–78, pygophore and parameres,, scale bars 0.5 mm; 77, ventral view; 78, dorsal view, mpp, medial process of pygophore, pa, paramere, pct, proctiger; 79, medial process of pygophore (pointed by an arrow), schematic outline, anterior view, scale bar 0.2 mm; 80–82, scale bars 1.0 mm; 80, phallus with inflated endosoma, lateral view; 81–83, dorsal view, 81, inflated endosoma; 82, articulatory apparatus and dorsal phallotecal sclerite, 83, dorsal phallotecal sclerite, parts indicated, scale bar 0.5 mm, bpa, basal plate arm, bpb, basal plate bridge, bpe, basal plate extension, dps, dorsal phallothecal sclerite, el, external layer of ventral endosoma wall, lc, longitudinal linear cleft of endosomal struts, mp, median process of endosoma, stp, subtriangular process of endosoma.

FIGURES 15–17. Brontostoma basalis (Stål, 1859), male from Suriname identified by P. Wygodzinsky. 15, dorsal view, scale bar 5.0 mm; 16, abdomen, ventral view, scale bar 2.0 mm; 17, labels.

FIGURES 18–21. Brontostoma basalis (Stål, 1859), males from French Guiana, scale bars 5.0 mm. 18–20, dorsal view, 20–21, same specimen, 21, ventral view.

FIGURES 22–27. Brontostoma basalis (Stål, 1859), males, scale bars 5.0 mm. 22–23, 24–25, same specimens from French Guiana; 26, specimen from Suriname; 27, specimen from Ecuador deposited in BMNH; 22, 24, 26–27, dorsal view, 23, 25, ventral view.

FIGURES 28–33. Brontostoma basalis (Stål, 1859), males from Peru. 28–32, scale bars 5.0 mm; 28–29, 30–31, 32–33, same specimens; 28, 30, 32, dorsal view; 29, 31, ventral view; 33, abdomen, ventral view, scale bar 2.0 mm.

FIGURES 34–42. Brontostoma basalis (Stål, 1859), male genitalia. 34, apical portion of abdomen with genital capsule in situ, ventral view, scale bar 2.0 mm; 35–37, abdominal segment VIII, scale bars 0.5 mm; 35, ventral view; 36, dorsal view; 37, lateral view; 38–39, pygophore and parameres, scale bars 1.0 mm; 38, ventral view, 39, dorsal view, after removing the phallus, parameres slightly moved apart, br, transverse bridge, mpp, medial process of pygophore, pa, paramere; 40, right paramere, lateral view, scale bar 0.5 mm; 41–42, medial process of pygophore (pointed by an arrow) of two different specimens from French Guiana, schematic outline, anterior view, scale bars 0.2 mm.

FIGURES 43–48. Brontostoma basalis (Stål, 1859), male genitalia, scale bars 0.5 mm. 43–46, phallus not inflated; 43–44, lateral view; 45, ventral view; 46–47, dorsal view; 47, articulatory apparatus and basal plate extension; 48, phallus with expanded endosoma, dorso-lateral view, bpa, basal plate arm, bpe, basal plate extension, bpb, basal plate bridge, dps, dorsal phallothecal sclerite, el, external layer of ventral endosoma wall, es, endosomal struts, mp, median process of endosoma, stp, subtriangular process of endosoma, vfa, acute apex of ventral curved fold (vf) of dorsal phallothecal sclerite.

FIGURES 49–53. Brontostoma basalis (Stål, 1859), male genitalia, phallus with inflated endosoma, scale bars 1.0 mm. 49–50, specimen from French Guiana; 49, dorsal view; 50, lateral view; 51, 53, lateroventral view; 51, specimen from Peru; 52–53, specimen from Suriname, 52, laterodorsal view, bpa, basal plate arm, bpe, basal plate extension, dps, dorsal phallothecal sclerite, el, external layer of ventral endosoma wall, es, endosomal struts, evf, endosomal ventral fold, mp, median process of endosoma, stp, subtriangular process of endosoma, vf, ventral curved fold of dorsal phallothecal sclerite.

FIGURES 54–60. Brontostoma basalis (Stål, 1859), male genitalia. 54–55, specimen from Peru, phallus with inflated endosoma, scale bars 1.0 mm; 54, dorsal view; 55, lateral view; 56–60, dorsal view; 56–57, scale bar 0.5 mm; 56, A–B, dorsal phallotecal sclerite, B, parts indicated; 57, specimen from Peru, inflated endosoma; 58–59, astp and mp at apical portion of endosoma; 58, specimen from Suriname identified by P. Wygodzinsky, scale bar 0.3 mm; 59–60, specimens from French Guiana, scale bar 0.2 mm; 60, process of endosoma detached from endosoma, astp, apex of subtriangular process of endosoma, bpa, basal plate arm, bpe, basal plate extension, dps, dorsal phallothecal sclerite, edf, endosomal dorsal fold, el, external layer of ventral endosoma wall, es, endosomal struts, evf, endosomal ventral fold, mp, median process of endosoma, slb, medial sinuous longitudinal borders of endosomal struts, stp, subtriangular process of endosoma, vfa, acute apex of ventral curved fold (vf) of dorsal phallothecal sclerite.