Revision of Taurocerus (Heteroptera, Pentatomidae, Pentatomini)

Taurocerus Amyot & Serville, 1843 is revised based on morphology of male and female genitalia. Four species are recognized: T. edessoides (Spinola, 1837), T. achiles Stål, 1862, T. abruptus (Walker, 1867), and T. amazonensis sp. nov. Illustrations of male and female genitalia and a key for the species are provided.

Taurocerus, with three nominal species, is an exclusively neotropical genus, distributed from Mexico to Central Brazil. SPINOLA (1837) described Arvelius edessoides, based on two specimens from Brazil.AMYOT & SERVILLE (1843) proposed the genus Taurocerus to include A. edessoides, redescribing the species based on material from Brazil, but included a question mark after its name, suggesting that his species was not conspecific with the Spinola's one.DALLAS (1851) listed in Taurocerus, as synonyms, A. edessoides Spinola and T. edessoides Amyot & Serville, based on four specimens from distinct localities from Mexico, Colombia and Brazil.STÅL (1862) described T. achilles and T. hector, both from Mexico.STÅL (1867) included Taurocerus in his key for the American pentatomid genera.WALKER (1867) listed T. achilles, T. hector, and following DALLAS (1851), T. edessoides; he also described Canaca abrupta, from Guatemala, and T. divergens, from Amazon region, distinguishing the latter from T. edessoides.STÅL (1872) considered T. edessoides Spinola and T. edessoides Amyot & Serville distinct species, the latter being a junior synonym of T. divergens.DISTANT (1880) considered T. divergens junior synonym of T. achilles, and T. hector junior synonym of T. edessoides Spinola; this author also transferred Canaca abrupta Walker, 1867 to Taurocerus.ROLSTON et al. (1980) included Taurocerus in their section 3 of Pentatomini genera which have a tubercle on third abdominal sternite, apposed to posterior margin of metasternal carina.BRAILOVSKY (1988) presented a differential diagnosis for Taurocerus, Arvelius Spinola and Pallantia Stål, with a brief redescription of T. edessoides.BRAILOVSKY et al. (1992) described eggs and nymphs of T. edessoides, providing some biological data.
Taurocerus is here revised, with the description of a new species based on specimens from Brazil and Peru.

MATERIAL AND METHODS
The specimens studied belong to the following collections: AMNH, American Museum of Natural History, New York, USA; BMNH, Natural History Museum, London, England;  (1970) and GRAZIA & BARCELLOS (1991).The female of T. abruptus was not dissected because it is known only from the type specimen.The type material of T. edessoides Amyot & Serville (= T. achilles Stål) was not found.Measurements (average, minimum and maximum values, standard deviation) are given in milimeters.Pronotum.Anterior half of the disc strongly declivent.Anterior border slightly concave.Antero-lateral angles toothed.Antero-lateral borders crenulated, more strongly on anterior half.Humeri strongly produced laterad or antero-laterad, apex posteriorly directed (laterally in T. abruptus).Posterolateral borders sinuated, concave on the anterior half and slightly convex posterad.Posterior border rectilinear.Medium-sized punctures distributed more densely around cicatrices and on posterior half of the disc.

Taurocerus Amyot & Serville, 1843
Scutellum.Coarse punctures irregularly distributed over basal half, decreasing in size toward apex.Apex with a V-shaped, yellowish callous, variable intraspecifically.In most of the specimens of T. edessoides, the arms of "V" are broad and closer to each other, making it cordiform in appearance; in some specimens, however, the "V" is faded.In T. achilles and the holotype of T. abruptus, the callus is thinner than in T. edessoides.In T. amazonensis sp.nov., the callous is also variable.
Hemelytra.Area between claval suture and R + M vein dull, with small punctures homogeneously distributed.Clavus and costal area shiny, coarsely punctured.Membrane with 12 to 15 longitudinal, parallel veins.
Ventral surface of thorax castaneous, more coarsely and densely puntured on ventral surface of prothorax, mesepimeron and metepisternum.Prosternum flat; mesosternum slightly more elevated, almost continuous with metasternum in profile.Metasternum sligthly elevated, laterally compressed; anterior margin entire, posterior margin slightly concave.Ostiolar rugae short, digitiform, reaching about 1/7 to 1/8 of the distance from inner margin of ostiole to lateral margins of metapleura.
Abdominal venter with a mesial, longitudinal keel; surface rarely punctured.Third sternite with a stout median tubercle, apposed to posterior margin of the metasternum.Tricobothria distributed on a longitudinal imaginary line across the middle of spiracles.Apical angles of connexivum acute, blackish.
Male genitalia.Pygophore subtrapezoidal to quadrangular.Dorsal rim slightly sinuous.X segment trapezoidal, wider basally.Parameres well-developed.Ventral rim excavated medially, with a median process, varying from an inconspicuous to acute tubercle; lateromedially, 1 + 1 processes, variable in shape and size.Posterolateral angles of pygophore mutic or with a small, acute tubercle.Phallus.Conjunctiva present, bearing or not processes.Phallotheca with 1 + 1 long and slender ventral processes.Ductus seminis distalis surpassing or not conjunctiva.Vesica with a ventral process, not visible in T. achilles.
Comments.The apical spines at femora, the mesial tubercle on third sternite, apposed to metasternal carena, and the morphological pattern of the phallus, make Taurocerus similar to Arvelius Spinola, from which can be distinguished by the darker general color, jugae apically rounded, shorter than clypeus; bucculae lobed posteriorly; obtuse apex of humeri, and, on ventral rim of the pygophore, the presence of a median and two lateromedian processes.
Comments.This species, known only from the holotype, may be distinguished from the other congeners by its tougher, laterally directed humeri, and by the shape of gonocoxites 8.
Genitalia reduced when compared to the other species of the genus, despite their similar body size.Pygophore subtrapezoidal, elliptical in caudal view, widely open dorsally.Proctiger subquadrangular.Parameres distally broad (fig.13), apex curved anterolaterally (fig.7).Dorsal rim slightly sinuated (fig.4).Posterolateral angles rounded apically, mutic.Ventral rim: median process inconspicuous; lateromedian processes obtuse, delimiting a median U-shaped excavation (fig.10).Phallus about one half as long as in the other species (figs. 16, 19, 22).Basal plate short, about one sixth as long as phallotheca.Visible part of processus phallothecae about one fifth of the length of phallotheca.Vesica little developed, without visible processes (maybe so in the everted phallus).Ductus seminis distalis short, not surpassing conjunctiva.Conjunctiva little-developed, with no evident processes.
Genitalia.Gonocoxites 8 broad and short, about two and a half times wider than long.Sutural borders contiguous at median third, divergent apically.Posterior borders of gonocoxites 8 slightly sinuated.Laterotergites 9 broad at the apex (fig.25).Secondary thickenings of gonapophysis 9 subtrapezoidal (fig.27).Comments.The general brown color and the blackish apices of humeri distinguish this species from T. edessoides and T. amazonensis.The size and shape of male genitalia, and the shape of gonocoxites 8 also separate T. achilles from their congeners.
Type-locality.Brazil.Type material.Lectotype and paralectotype , here designated.The material belongs to Spinola's collection, at present deposited at MRSN.A green label in the box, containing the following data: Arvelius edessoides Spin., G. taurocerus, A. et S. , D. Bouquet, Brésil .
Type material of T. hector examined.Stål described this species based on two males from Mexico and one female from unknown locality.We received from NHRS three males labeled as "typus" (loan number 1068/99) and "paratypus" (numbers 1069/99 and 1070/99), the last one collected in Bogotá [Colombia] by Alexander Lindig.We believe that the specimen 1070/99 is not actually a syntype of T. hector and the female mentioned in the Stål's original description is missed.Then, we here designate as lectotype and paralectotype, respectively: 1 , labeled: a) Vera Cruz Description.Dorsal surface reddish-castaneous, abdominal venter reddish.Apex of humeri yellow.Rostrum reaching the fourth abdomninal sternite.Vshaped callous of scutellum, in the most of the specimens examined, with broad and closed arms, becoming cordiform in appearance; in some specimens, however, the callous is faded.
Genitalia.Gonocoxites 8 triangular, about one and a half wider than long (fig.26).Sutural borders of gonocoxites 8 convergent, contiguous at apical half.Posterior borders concave near laterotergites 9. Laterotergites 9 narrow at apex.Secondary thickenings of gonapophysis 9 ear-like (fig.28).Comments.The color of the specimens varies from reddish to dark reddish-castaneous; the length of humeri is also variable, but the apices are always yellowish.The size and the triangular shape of gonocoxites 8, combined with the color of humeri distinguish T. edessoides from T. achilles and T. abruptus.