Research Article |
Corresponding author: Kelly Miller ( kbmiller@unm.edu ) Academic editor: Mariano Michat
© 2016 Kelly Miller.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Miller KB (2016) New species of Bidessonotus Régimbart, 1895 with a review of the South American species (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Bidessini). ZooKeys 622: 95-127. https://doi.org/10.3897/zookeys.622.9155
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The South American species of the New World genus Bidessonotus Régimbart, 1895 are reviewed with descriptions of seven new species. This brings the total number of valid Bidessonotus species to 37, making it the largest Bidessini genus in the New World. The new species are B. annae sp. n. (Venezuela), B. josiahi sp. n. (Venezuela), B. palecephalus sp. n. (Venezuela), B. reductus sp. n. (Venezuela), B. septimus sp. n. (Venezuela), B. spinosus sp. n. (Venezuela), and B. valdezi sp. n. (Guyana, Suriname). New distribution records are provided for many other South American Bidessonotus species. The main diagnostic features of Bidessonotus species are in the male genitalia, and these are illustrated for all South American species. Diagnostic features, distributions (including distribution maps), and additional comments are provided for all South American species.
Las especies sudamericanas del género del Nuevo Mundo Bidessonotus Regimbart, 1895 (Coleoptera: Adephaga: Dytiscidae: Hydroporinae: Bidessini) se revisan con descripciones de siete especies nuevas. Se eleva el número total de especies válidas en Bidessonotus a 37, el género más grande de Bidessini en el Nuevo Mundo. Las especies nuevas son B. annae sp. n. (Venezuela), B. josiahi sp. n. (Venezuela), B. palecephalus sp. n. (Venezuela), B. reductus sp. n. (Venezuela), B. septimus sp. n. (Venezuela), B. spinosus sp. n. (Venezuela), y B. valdezi sp. n. (Guyana, Surinam). Se incluyen nuevos registros distribucionales para la mayoría de las otras especies de Bidessonotus en América del Sur. Los principales caracteres diagnósticos para las especies de Bidessonotus están en los órganos genitales de los machos, los cuales se ilustran para todas las especies sudamericanas. También se incluyen caracteres diagnósticos, mapas de distribución, y comentarios adicionales para todas las especies sudamericanas.
Water beetles, taxonomy, classification, Neotropical, Bidessonotus , Dytiscidae , Coleoptera
The New World Bidessini genus Bidessonotus Régimbart (Coleoptera: Dytiscidae: Hydroporinae) included, prior to this paper, 30 species, making it one of the largest genera in the tribe in the New World with only Neobidessus Young (30 species) and Liodessus Guignot (27 species) comparable in size. There are three species in eastern and southern North America, numerous species in Central America and the Caribbean and additional species in South America. Although many Bidessonotus species are widespread, others are relatively narrowly distributed, and new species are likely to be discovered with additional collecting efforts in undercollected areas of South America.
Bidessonotus are easily diagnosed by the presence of relatively distinctively pentamerous pro- and mesotarsi (Fig.
The genus was originally described by
Collecting in poorly known areas of northern South America during the past decade has led to discovery of seven previously undescribed species of Bidessonotus, and these are described here. This brings the number of known species to 37. New records of other South American species are also presented here along with brief diagnostic descriptions, illustrations, additional comments, and distributions.
Measurements. Measurements were made with an ocular scale on a Zeiss Discovery V8 dissecting microscope. Emphasis was placed on getting the diagnostic range of measurements of structures rather than finding the average or taking a random sample. Measurements include: 1) total length (TL), 2) greatest width across elytra (GW), 3) greatest width of pronotum (PW), 4) greatest width of head (HW), and 5) distance between eyes (EW). The ratios TL/GW, HW/EW and FW/FL were also calculated.
Images. Illustrations were made using a drawing tube on a Zeiss Discovery V8 dissecting scope. Sketches were first done in pencil then scanned, placed into an Adobe Illustrator artboard and “inked” digitally using vector lines. The illustration of the male median lobe of B. bicolor was redrawn from
Material. Specimens were examined from the following collections:
CSBD
Center for Biological Diversity,
KBMC
Kelly B. Miller Collection,
KUNHM
MSBA
Label data for holotype specimens are reported verbatim. All other label data, including for paratypes, are reported in a standardized format. All paratypes have a blue label with a black line border bearing the species name attached to them.
Distribution maps. Dot maps presented here are derived from examined specimens and specific localities reported by
Bidessonotus are superficially extremely similar to each other with a similar body shape and coloration. There are some distinctive character systems, however, that require some explanation.
Head. The anterior surface of the clypeus of some Bidessonotus has a moderately distinctive transverse shallow sulcus which may be interrupted medially.
Pronotum. The basal pronotal plicae are somewhat variably impressed with some species deeply and others more shallowly. However,
Prosternal process. The prosternal process in Bidessonotus is elongate and slender. There is some variability in the relative width and the apex that ranges from sharply pointed to rounded. The surface may be convex to flat to somewhat sulcate, features emphasized by
Male genitalia. Dytiscid male genitalia are rotated in such a way as to make describing orientation of structures difficult. This paper follows
Sexual dimorphism. All Bidessonotus species are distinctively sexually dimorphic. The metaventrite and medial portions of the metacoxae are distinctly concave in males (Fig.
Venezuela, Apure State, Communidad Caño Gato, on Rio Sipapo, 4°58.838'N, 67°44.341'W.
Specimens of this species are brown with irregular, indistinct paler regions. The prosternal process is laceolate, shallowly sulcate and apically pointed. The female elytron is unmodified. The apical blade of the male median lobe is slender and curved with an elongate, curved, apically narrowly rounded process at the apicoventral angle, and the dorsal margin narrowly truncate (Fig.
Bidessonotus species, male genitalia A median lobe, right lateral aspect B right lateral lobe, right lateral aspect C left lateral lobe, apical segment, left lateral aspect D median lobe apex, oblique right lateral aspect 12 B. annae 13 B. josiahi 14 B. palecephalus 15 B. reductus 16 B. septimus 17 B. spinosus 18 B. valdezi.
Measurements. TL = 1.7–1.8 mm, GW = 0.8–0.9 mm, PW = 0.7–0.8 mm, HW = 0.5–0.6 mm, EW = 0.3 mm, TL/GW = 2.0–2.1, HW/EW = 1.9. Body shape elongate, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin evenly rounded; surface smooth and shiny, impuncate, slightly microreticulate; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae moderately impressed, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface overall shiny, slightly microreticulate, finely punctate. Elytron with lateral margins broadly curved; basal stria distinct, elongate, moderately impressed; surface of elytron covered with fine punctation, surface between punctures matte, microreticulate. Prosternal process elongate, lanceolate, apically pointed, surface broadly convex throughout length. Metaventrite with distinctive carinae extending from medial apex of metaventrite process posteriorly to near posterior margin at anterior terminus of metacoxal lines; anteriorly very closely approximated, divergent to posterior margin; surface of metaventrite shiny with few micropunctures. Metacoxae shiny with few micropunctures; metacoxal lines distinct, broad apically, broadly curved with external surface convex, convergent anteriorly. Basal abdominal ventrites punctate, other surfaces of abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with apical blade narrow, curved, with apicoventral elongate, curved process, ventral margin subtruncate, proximal margin curved (Fig.
Variation. Only a single male specimen examined.
Sexual dimorphism. Only a single male specimen examined.
This species is named annae after the author’s daughter, Annie Miller.
This species is known from one locality in Apure State, Venezuela (Fig.
The habitat where the type series was collected is a sandy forest stream with large deposits of leaf pack along the margins.
Holotype in
Venezuela, Apure State, between “La Ye” and Bruzual, 7.644°N, 69.300°W.
Specimens of this species are brown with moderately distinctive maculae. The prosternal process is lanceolate and flat with the apex pointed. The female elytron is apicolaterally broadly lobed (Fig.
Measurements. TL = 2.2–2.3 mm, GW = 1.1–1.2 mm, PW = 0.9 mm, HW = 0.6 mm, EW = 0.3 mm, TL/GW = 2.0, HW/EW = 2.0. Body shape elongate, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin evenly rounded; surface smooth and shiny, with few punctures medially; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae strongly impressed, especially basally, broad, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface overall slightly matte, but shiny, medial surface finely punctate. Elytron with lateral margins broadly curved; basal stria distinct, elongate, well impressed basally; surface of elytron covered with fine punctation, surface between punctures shiny. Prosternal process elongate, lanceolate, apically pointed, surface broadly convex throughout length. Metaventrite with distinctive carinae extending from medial apex of metaventrite process posteriorly to near posterior margin at anterior terminus of metacoxal lines; anteriorly very closely approximated, divergent to posterior margin; surface of metaventrite shiny with few micropunctures. Metacoxa shiny with few micropunctures; metacoxal lines distinct, broad, broadly curved with external surface convex, slightly convergent anteriorly. Basal abdominal ventrites punctate, other surfaces of abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with apical blade broad, with apicoventral rounded prominence, broad apicodorsal tooth, proximal margin straight, without tooth, ventral margin broadly pointed (Fig.
Variation. Specimens are variable in the extent of the pale markings on the elytron.
Sexual dimorphism. With typical Bidessonotus dimorphism. Males with apicolateral margin of elytron evenly curved (Fig.
This species is named josiahi after the author’s son, Josiah Miller.
The species is known from northern Venezuela (Fig.
The type specimens were collected from a “lagoon.”
Holotype in
Venezuela, Guarico, N of Palenque, 9.113°N, 66.993°W.
This is a relatively pale brown species. The head color in specimens of B. palecephalus is overall pale, unlike B. melanocephalus which has the base of the head darkened. The prosternal process is flat and apically pointed. Females have the apicolateral elytral margins developed into a prominent lobe (Fig.
Measurements. TL = 1.9–2.0 mm, GW = 1.0 mm, PW = 0.8–0.9 mm, HW = 0.5–0.6 mm, EW = 0.3 mm, TL/GW = 1.8–2.0, HW/EW = 1.8–2.0. Body shape elongate oval, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin slightly thickened, evenly rounded; surface smooth and shiny; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae strongly impressed, broad, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface overall slightly matte, but shiny, surface mediad of striae distinctly punctate. Elytron with lateral margins broadly curved; basal stria distinct, elongate, well impressed basally; surface of elytron covered with fine punctation, surface between punctures shiny. Prosternal process elongate, apically pointed, surface broadly convex throughout length. Metaventrite with distinctive carinae extending from medial apex of metaventrite process posteriorly to near posterior margin at anterior terminus of metacoxal lines; surface of metaventrite shiny with few micropunctures. Metacoxae shiny with few micropunctures; metacoxal lines distinct, broad, broadly curved with external surface convex, slightly convergent anteriorly. Basal abdominal ventrites punctate, other surfaces of abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with blade elongate, with apicoventral tooth, submedial broad tooth on distal margin and broad tooth along proximal margin, dorsal margin broad and obliquely truncate (Fig.
Variation. Specimens vary in the extent and intensity of the elytral fasciae and maculations.
Sexual dimorphism. With typical dimorphism found in Bidessonotus. Males with apicolateral margin of elytron evenly curved (Fig.
The species is named palecephalus from the Greek words pale, meaning “pale,” and cephalus, meaning “head,” for the pale head of specimens in comparison with the somewhat similar species B. melanocephalus.
The species is known from Apure and Guarico, Venezuela (Fig.
Nothing is known of the habitat of this species.
Holotype in
Venezuela, Bolivar State, Gran Sabana, N Santa Elena, Rio Guara at Rt. 10, 04°37.362'N, 61°05.679'W.
Specimens of this species are small and pale (Fig.
Measurements. TL = 1.8–2.0 mm, GW = 0.9–1.0 mm, PW = 0.8 mm, HW = 0.5 mm, EW = 0.3 mm, TL/GW = 2.0, HW/EW = 1.7–1.8. Body shape elongate oval, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin evenly rounded; surface smooth and shiny, with few micropunctures medially; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae distinctly impressed, especially basally, elongate, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface shiny, medial surface finely punctate. Elytron with lateral margins broadly curved; basal stria distinct, elongate, well impressed; surface of elytron covered with fine punctation, surface between punctures somewhat shiny but microreticulate. Prosternal process moderately broad, broadly oval, apex rounded, surface broadly convex throughout length. Metaventrite with distinctive carinae extending from medial apex of metaventrite process posteriorly to near posterior margin at anterior terminus of metacoxal lines; anteriorly very closely approximated, strongly divergent to posterior margin; surface of metaventrite shiny, impunctate. Metacoxae shiny, nearly impunctate; metacoxal lines distinct, broadly separated, anteriorly slightly divergent. Abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with blade reduced, slender, sharply pointed at dorsal margin (Fig.
Variation. The two specimens vary somwhat in the extent and intensity of the pale elytral areas.
Sexual dimorphism. Specimens of this species with typical Bidessonotus sexual dimorphism and female more matte dorsally than male. Without other evident dimorphisms.
This species is named reductus, Latin for “reduced,” for the relatively small apical blade of the male median lobe.
Known only from the Gran Sabana, Bolivar State, Venezuela (Fig.
Specimens have been collected from “marshy areas.”
Holotype in
Venezuela, Apure, Bruzual, edge of town, 8.042°N, 69.342°W.
Specimens of this species are medium-sized and dark with moderately well-developed, but somewhat diffuse maculae. The prosternal process is moderately broad, sulcate and apically pointed. The male genitalia are characteristic with the apical blade of the median lobe broad with a moderately well-developed apicoventral triangular prominence, the dorsal margin rounded, and the proximal margin oblique and distinctly undulate (Fig.
Measurements. TL = 2.0 mm, GW = 1.0 mm, PW = 0.8 mm, HW = 0.6 mm, EW = 0.2 mm, TL/GW = 2.0, HW/EW = 2.3. Body shape elongate, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin evenly rounded; surface smooth and shiny, with few micropunctures medially; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae strongly impressed, especially basally, elongate, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface shiny, medial surface finely punctate. Elytron with lateral margins broadly curved; basal stria distinct, elongate, well impressed; surface of elytron covered with fine punctation, surface between punctures matte, microreticulate. Prosternal process narrow, elongate, lanceolate, apex pointed, surface broadly convex throughout length. Metaventrite with carinae extending from medial apex of metaventrite process posteriorly, effaced and indistinct for much of length, marked mainly by smooth longitudinal area; anteriorly very closely approximated, strongly divergent to posterior margin; surface of metaventrite shiny, impunctate. Metacoxae shiny, nearly impunctate; metacoxal lines distinct, moderately separated, subparallel, slightly curved anteriorly forming slight lateral bulge. Abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with blade broad, with apicoventral tooth, ventral tooth near apical base of shaft, angulate, oblique proximal margin, dorsal margin rounded, produced (Fig.
Variation. Only a single specimen was examined.
Sexual dimorphism. Only a single specimen was examined.
This species is named septimus, Latin for “seventh,” since there are seven species described in Bidessonotus herein.
The single specimen was found in Apure State, Venezuela.
The holotype was collected from a “large marsh.”
Holotype in
Venezuela, Bolivar, Gran Sabana, Rio Aponwao at Rt 10, 5.847°N, 61.467°W.
Individuals have brown elytra with diffuse, poorly defined paler regions. The prosternal process is broadly oval, apically rounded and not sulcate. The female elytron has the apicolateral margin developed into a distinctive spine (Fig.
Bidessonotus species, male genitalia; A median lobe, right lateral aspect B right lateral lobe, right lateral aspect C left lateral lobe, apical segment, left lateral aspect D median lobe apex, oblique right lateral aspect 19 B. bicolor (redrawn from Guignot, 1957) 20 B. dubius 21 B. melanocephalus 22 B. obtusatus 23 B. otrerus 24 B. paludicolus 25 B. ploterus 26 B. rubellus 27 B. tibialis 28 B. truncatus 29 B. vicinus.
Measurements. TL = 2.0 mm, GW = 1.0 mm, PW = 0.8–0.9 mm, HW = 0.6 mm, EW = 0.3 mm, TL/GW = 2.0, HW/EW = 1.7–1.8. Body shape elongate oval, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin slightly thickened laterally, broadly rounded; surface smooth and shiny; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae moderately impressed, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface overall shiny, surface mediad of striae slightly punctate. Elytron with lateral margins broadly curved; basal stria distinct, moderately elongate, well impressed basally; surface of elytron covered with punctation, surface between punctures shiny but with distinctive microreticulation. Prosternal process elongate, lanceolate, apically pointed, surface broadly convex throughout length. Metaventrite with carinae extending from medial apex of metaventrite process posteriorly to posterior margin at anterior terminus of metacoxal lines; lines narrowly separated anteriorly, slightly divergent posteriorly and somewhat effaced; surface of metaventrite shiny with few micropunctures. Metacoxa shiny with few micropunctures; metacoxal lines distinct, nearly parallel, width slightly increased near anterior margin making lines slightly undulate anteriorly. Basal abdominal ventrites punctate, other surfaces of abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with apical blade broad, with apicoventral sharp tooth, long spinous apicodorsal tooth, dorsal margin broadly subtruncate, proximal margin irregular (Fig.
Variation. The two specimens vary in the extent and intensity of the elytral fasciae and maculations.
Sexual dimorphism. With typical sexual dimorphism for Bidessonotus. Male with anteroapical margin of elytron evenly curved; female with anteroapical margin produced into small spine (Fig.
This species is named spinosus, Latin for “thorny,” for the long apical spine on the apex of the male median lobe.
Specimens were collected from a “small vegetated pool” and a “small streamlet.”
Holotype in
Guyana, Region 6, Upper Berbice, ca 1km S Basecamp 1, 4°09.289'N, 58°12.274'W.
Specimens of B. valdezi are relatively pale brown with the elytral maculae indistinct and vague. The prosternal process is lanceolate, shallowly sulcate and apically pointed. The apical blade of the male median lobe is broad with a moderately developed apicoventral triangular prominence, the distal margin sublinear, the proximal margin obliquely linear, and the dorsal margin narrowly truncate (Fig.
Measurements. TL = 1.8–1.9 mm, GW = 0.9 mm, PW = 0.7 mm, HW = 0.5 mm, EW = 0.3 mm, TL/GW = 2.0–2.1, HW/EW = 1.8. Body shape elongate oval, lateral outline discontinuous between pronotum and elytron.
Coloration (Fig.
Sculpture and structure. Head with anterior clypeal margin slightly thickened laterally, broadly rounded; surface smooth and shiny; antennomeres III-X moderately broad, slightly asymmetrical. Pronotum widest near posterior angles, lateral margins evenly curved; basal striae moderately impressed, extending anteriorly more than halfway across surface; posterior margins distinctly undulate; surface overall shiny, surface mediad of striae slightly punctate. Elytron with lateral margins broadly curved; basal stria distinct, moderately elongate, well impressed basally; surface of elytron covered with punctation, surface between punctures shiny but with distinctive microreticulation. Prosternal process elongate, lanceolate, apically pointed, surface broadly convex throughout length. Metaventrite with carinae extending from medial apex of metaventrite process posteriorly to posterior margin at anterior terminus of metacoxal lines; lines narrowly separated anteriorly, slightly divergent posteriorly and somewhat effaced; surface of metaventrite shiny with few micropunctures. Metacoxae shiny with few micropunctures; metacoxal lines distinct, nearly parallel, width slightly increased near anterior margin making lines slightly undulate anteriorly. Basal abdominal ventrites punctate, other surfaces of abdominal ventrites smooth, relatively shiny.
Male genitalia. Apex of median lobe in lateral aspect with apical blade moderately broad, with anteroventral triangular prominence, dorsal margin truncate, proximal margin obliquely curved (Fig.
Variation. Specimens vary in the extent and intensity of the elytral fasciae and maculations. In some specimens the lighter regions of the elytra are somewhat more intensely pale and slightly more distinctly defined.
Sexual dimorphism. With typical sexual dimorphisms for Bidessonotus species. Females with dorsal surface more matte than in males.
The species is named valdezi after the good friend of the author and eminent biologist, Dr. Ernest Valdez.
Known from Guyana and Suriname (Fig.
Specimens have been found in “muddy detrital pools” in a drying creek bed,“detritus pools” in a dry creek bed, and a “pooled up creek.”
Holotype in CSBD, male labeled, “GUAYANA: Region 6 4°09.289'N, 58°12.274'W, 108m Upper Berbice, ca. 1 km S. Basecamp 1 detrius pools in dry creekbed leg. Short, Salisbury, La Cruz 26.ix.2014; GY14-0825-01D/ SECM1358746 KUNHM-ENT [barcode label]/ HOLOTYPE Bidessonotus valdezi Miller, 2016 [red label with black line border].” paratypes 12, Guyana: Region 6, Upper Berbice, Basecamp 1, 4°09.289'N, 58°12.274'W, 72m, muddy detrital pools in drying creekbed near camp, Short, Salisburg, La Cruz, legs., 21 Sep 2014, GY14-0821-02A (2,
Bidessonotus
bicolor
Guignot, 1957: 36;
Bidessonotus bicolor is inadequately known and a diagnosis is difficult to establish. The apical blade of the male median lobe is relatively small with a spinous process at the apicoventral angle, a triangular prominence medially on the distal margin, and a pointed dorsal apex (Fig.
The type was not found and no other specimens were examined by
Known only from the type locality, Brazil, Pará, Cachimbo (Fig.
Bidessonotus
dubius
Young, 1990a: 364;
Specimens of Bidessonotus dubius are moderately darkly colored with fairly well defined pale maculae on the elytra. The prosternal process is narrow and not or slightly sulcate and apically pointed. The apical blade of the male median lobe is diagnostic with a weakly developed apicoventral prominence and the dorsal apex broadly rounded with an undulating proximal margin (Fig.
Known from throughout northern South America (Fig.
Bidessonotus
melanocephalus
Régimbart, 1895: 332; J.
Bidessus (Bidessonotus) melanocephalus
,
Bidessus
melanocephalus
,
Specimens of B. melanocephalus are darkly colored with the posterior surface of the head and the ventral surfaces dark brown. The prosternal process is lanceolate but not sulcate. The apical blade of the male median lobe is very broad with very well developed apicoventral and apicodorsal teeth and a broad tooth near the medial end of the proximal margin (Fig.
Known from Brazil and Peru (Fig.
Bidessonotus
nepotinus
J.Balfour-Browne, 1947: 442;
Known only from a pair of females which are moderately darkly colored with three indistinct transverse maculae. The apex of the prosternal process is lanceolate. Given the absence of known males, a definitive diagnosis is difficult to establish.
Bidessonotus nepotinus is known only from two female specimens (
Bidessonotus nepotinus is known only from Trinidad (Fig.
Bidessonotus
obtusatus
Régimbart, 1895: 336; J.
Bidessus (Bidessonotus) obtusatus
,
Bidessus
obtusatus
,
Specimens of this species are rather darkly colored with variable light markings that are usually conspicuous. The anterior clypeal margin is weakly sulcate and medially rounded. The prosternal process is relatively broad, flat and apically narrowly rounded. The male median lobe is diagnostic with the apical blade broadly truncate on the ventral margin, broad dorsally with a prominent obliquely truncate apicodorsal projection and the proximal margin with a small, irregular medial tooth and more well developed dorsal tooth (Fig.
This is one of the commonest species in much of lowland South America with specimens collected especially from marshy lentic habitats and at lights.
Specimens have been collected from throughout lowland South America (Fig.
Bidessonotus
otrerus
Young, 1990: 368;
Bidessonotus otrerus is a brownish species with significant portions of the head and pronotum brown. The elytra are brown with weakly pale maculae. The prosternal process is narrow and slightly sulcate. The apical blade of the male median lobe is slender and dorsally narrowly rounded, the distal and proximal margins are irregularly undulate (Fig.
Little is known of this species.
Bidessonotus
paludicolus
Young, 1990: 372;
Specimens are relatively darkly colored with the posterior surface of the head brown and the elytra evenly dark brown. The prosternal process is narrow and slightly sulcate. The male median lobe has the apical blade narrow ventrally and evenly and broadly expanded dorsally with the dorsal margin broadly truncate (Fig.
Bidessonotus
ploterus
Young, 1990;
Specimens are relatively evenly brownish on the elytra with poorly-developed maculae. The prosternal process is lanceolate and slightly sulcate. This is a relatively small species (1.3-1.7 mm). The apical blade of the male median lobe is narrow with a relatively well developed anteroventral rounded prominence and the dorsal margin of the blade broadly truncate with a moderately distinctive medial tooth on the proximal margin (Fig.
This species is known from Brazil (Mato Grosso) (Fig.
Bidessonotus
rubellus
Young, 1990: 366;
Specimens are relatively darkly colored with the posterior surface of the head brown and the elytra dark reddish-brown with indistinct maculae. The prosternal process is moderately broad, apically rounded and not sulcate. The apical blade of the male median lobe is similar to that of B. obtusatus but is narrower, has the apicoventral region obiquely truncate and larger with the apicoproximal tooth more strongly developed (Fig.
Bidessonotus rubellus was thought to have genitalia similar to B. obtusatus by
Bidessonotus rubellus has been reported from Colombia, Ecuador, Panama, Paraguay and Venezuela (Fig.
Bidessonotus
tibialis
Régimbart, 1895: 337; J.
Bidessus (Bidessonotus) tibialis
,
Bidessus
tibialis
,
Bidessonotus
sobrinus
J. Balfour-Browne, 1947: 445;
Specimens have the elytra relatively uniformly-colored except in some specimens with darker and lighter markings, but poorly evident. The prosternal process is lanceolate and distinctly sulcate. The male genitalia are diagnostic with the apical blade moderately slender and distinctly and abruptly curved with the dorsal margin rounded and with a distinct anteroventral rounded prominence (Fig.
This species and B. sobrinus are extremely similar, and
Bidessonotus tibialis is widespread in northern South America with records also from Bolivia, Brazil and Peru (Fig.
Bidessonotus
truncatus
J. Balfour-Browne, 1947: 440;
Specimens of this species are darkly colored with the elytra nearly evenly dark brown. The prosternal process is relatively broad, flat, apically pointed, and weakly or not sulcate. The apical blade of the male median lobe is slender with the distal margin medially with an elongate spinous “horn” or process (Fig.
Little has been reported about this species, but specimens were collected from both lentic and slow lotic habitats.
Known from Bolivia, Brazil, Guayana, Paraguay, Peru, Suriname and Trinidad (Fig.
Bidessonotus
vicinus
J. Balfour-Browne, 1947: 428;
This is a relatively dark and weakly maculate species. The prosternal process is lanceolate, flat and apically pointed. The apical blade of the male median lobe is relatively simple, the anteroventral angle is moderately produced as a broad, curved, short process, the distal margin is broadly truncate to slightly undulate, and there are no other prominent spines, denticles or projections (Fig.
Although originally described from a female,
Bidessonotus annae sp. n. – Venezuela
B. bicolor Guignot, 1957 – Brazil
B. browneanus J. Balfour-Browne, 1947 – Cuba, Dominican Republic, Jamaica, Puerto Rico
B. canis Miller, 1997 – Costa Rica
B. caraibus (Chevrolat, 1863) – Belize, Cuba
B. championi J. Balfour-Browne, 1947 – Costa Rica, Guatemala, Honduras, Nicaragua
B. dubius Young, 1990 – Brazil, French Guiana, Suriname, Venezuela
B. fallax J. Balfour-Browne, 1947 – Cuba
B. inconspicuus (LeConte, 1855) – Canada, USA (eastern states)
B. inigmaticus Young, 1990 – Mexico
B. josiahi sp. n. – Venezuela
B. longovalis (Blatchley, 1919) – USA (Alabama, Florida, Georgia)
B. melanocephalus Régimbart, 1895 – Brazil, Peru
B. mexicanus Régimbart, 1895 – Belize, Mexico, USA (Texas)
B. mobilis J. Balfour-Browne, 1947 – Belize, Guatemala, Mexico
B. morosus J. Balfour-Browne, 1947 – Mexico
B. nepotinus J. Balfour-Browne, 1947 – Trinidad
B. obtusatus Régimbart, 1895 – Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Paraguay, Peru, Suriname, Venezuela
B. otrerus Young, 1990 – Colombia, Venezuela
B. palecephalus sp. n. – Venezuela
B. paludicolus Young, 1990 – Costa Rica, Mexico, Venezuela
B. peregrinus J. Balfour-Browne, 1947 – Panama
B. pictus Young, 1990 – Costa Rica
B. ploterus Young, 1990 – Brazil
B. pollostus Young, 1990 – Belize
B. pulicarius (Aubé, 1838) – USA (Alabama, Florida, Georgia, Louisiana, Mississippi)
B. reductus sp. n. – Venezuela
B. regimbarti J. Balfour-Browne, 1947 – Mexico?
B. rhampherens Young, 1990 – Mexico
B. rubellus Young, 1990 – Colombia, Ecuador, Panama, Paraguay, Venezuela
B. septimus sp. n. – Venezuela
B. spinosus sp. n. – Venezuela
B. tibialis Régimbart, 1895 – Bolivia, Brazil, Peru (also Colombia, Panama, Suriname, Venezuela as B. sobrinus)
= B. sobrinus J. Balfour-Browne, 1947, syn. n.
B. truncatus J. Balfour-Browne, 1947 – Bolivia, Brazil, Guyana, Paraguay, Peru, Suriname, Trinidad
B. valdezi sp. n. – Guiana, Suriname
B. vicinus J. Balfour-Browne, 1947 – Honduras, Panama, Venezuela
Thanks to C. Micheli, K.E. Schnepp, A.E.Z. Short, and P. Skelley for specimens. Portions of this work were funded by the following grants: NSF #DEB-0816904, #DEB-0845984 and #DEB–1353426.