Pseudodisersus goudotii (Guérin-Méneville)

Pseudodisersus goudotii (Guérin-Méneville)

Potamophilus goudotii Guérin-Méneville, 1843:18.—Coquérel, 1851:597.

Disersus goudotii.—Sharp, 1882:127.

Disersus goudoti.—Zaitzev, 1908:288; 1910:7.—Blackwelder, 1944:272.

Pseudodisersus coquereli Brown, 1981:100 [new synonym].

MALE.—Body Form and Size: Elongate, subparallel, moderately convex dorsally. Length, 6.4 mm; width, 2.1 mm.

Coloration: Blackish brown dorsally. Antennal segments 1 and 2 reddish brown; antennal segments 3–11 black. Venter blackish brown except basal segments of all palpi; labium; maxillae; coxae; trochanters; bases of femora, mesotibiae, metatibiae, and tarsi reddish brown.

Head: Finely, densely punctate; punctures separated by a distance equal to or less than diameter of a puncture. Eyes large, hemispherical. Clypeus broadly, arcuately emarginate anteriorly. Labrum densely and moderately coarsely punctate; anterior margin unmodified, almost truncate, and densely fringed with long, fine, golden, hair-like setae; anterolateral angles rounded and only moderately expanded laterally.

Thorax: Pronotum slightly widest just before base; length, 1.2 mm; width, 2.0 mm; sides arcuate; anterolateral angles obtuse; with distinct constriction posterolaterally of each angle resulting from deep transverse impression across apical fourth of pronotum; apex arcuate; base strongly sinuate; with a robust tubercle on each side of midline in front of scutellum; each tubercle preceded by a small gibbosity with a slight depression anterolaterally; posterolateral angles obtuse, obscured by a strongly raised dentiform tubercle at lateral margin that arises before true posterolateral angle; surface with deep transverse impression across apical fourth; with sublateral, moderately deep impressions separating strong sublateral lobe from smaller basolateral lobe; midline longitudinally depressed behind transverse depression, more deeply so on basal half; discal area finely densely punctate, punctures separated by distance equal to about half their diameter. Prosternum short in front of procoxae; depressed medially. Prosternal process broadly V-shaped; base broadest then converging to narrowed but rounded apex; narrowed apical third of process flat. Mesosternum deeply and broadly excavated for reception of apex of prosternal process. Metasternum convex on each side of midline; deeply and broadly depressed posteromedially between metacoxae; surface microreticulate and punctate; punctures moderately coarse and sparse, separated by 1 or 2 times their diameter. Procoxae and metacoxae moderately widely separated; mesocoxae slightly more widely separated. Legs strongly compressed dorsoventrally, flattened. Mesotibiae with lateral surface finely alutaceous; without dense hydrofuge pubescence except a very small area at base and a narrow strip on medial (lower) and lateral (upper) surface. Metatibiae with lateral surface lightly, finely alutaceous; virtually impunctate; with basal half densely pubescent and sharply delineated from glabrous area (Figure 119). Tarsal claws moderately long and very stout. Elytron with 10 rows of coarse punctures, punctures separated by 1 or 1½ times their diameter; intervals very finely alutaceous and finely, densely punctate; punctures on intervals separated by distance equal to their diameter or slightly less and obscured by dense pubescence; humeral area strongly tumid; sides of elytra distinctly margined and almost parallel; apex moderately dehiscent, evenly arcuate laterally and terminating in evenly rounded apex (Figure 122).

Abdomen: Sterna 1–4 becoming progressively shorter. Sternum 1 with distinct longitudinal carina extending from metacoxa almost to hind margin each side of midline. Apex of last sternum rounded (Figure 120).

Male Genitalia: As illustrated (Figures 115, 116).

FEMALE.—Similar to male except metasternum less deeply and less broadly depressed medially. Apex of last abdominal sternum subtruncate (Figure 121). Elytral apices slightly more produced (Figure 124) than those of male. Genitalia as illustrated (Figures 117, 118).

VARIATIONS.—The elytral apices of the series of specimens from Panama are evenly arcuate laterally and consistently terminate in rounded apices (Figure 122). The specimens from Ecuador have the apices distinctly dehiscent, slightly sinuous laterally, and terminate in elongated apices (Figure 123). These differences were sufficient to suggest to us that we might be dealing with two distinct species. However, other characters, including the male genitalia, confirmed that we were looking at variation in the shape of the elytral apices. Consequently, we presently recognize only one species, Pseudodisersus goudotii, in this genus.

TYPE DATA.—The female type specimen of goudotii is from “Nouvelle-Grenade” [COLOMBIA]: Rio Chipalo [at 04°38′N 74°52′W near Viota, about 30 miles [48 km] SW of Bogota in Departamento Cundinamarca]. In the article by Guérin-Méneville (1843) he described two species, Potamophilus goudotii (= Disersus) and P. cordillierae (= Hexanchorus) in that sequence. Following the description of P. cordillierae he described the collection site as follows. “J'ai trouvé ces deux espèces ensemble sur des pierres au milieu de la rivière Chipalo. Elles se tiennent tout près de l'eau et sont continuellement mouillées par les petites vagues du courant. Je les ai prises en septembre et octobre en même temps que les Oxycheila aquatica.”

The type specimen of P. goudotii kindly lent to us by Mlle. N. Berti is a female bearing the following labels: (1) A large (15 mm) blue circular label: “P./Goudoti/Guerin/Columbia.” (2) A female sex sign on a white rectangle. (3) A light blue rectangle: “Museum Paris/Collection/Generale.” (4) A red rectangle: “?Type.”

The elytral apices of the type specimen are broken off or were eaten away by a pest. However, what remains appears to have been explanate and prolonged posteriorly. This and other distinguishing characters—truncate hind margin of last abdominal sternum, carinae of first abdominal sternum, non-pubescent area on metatibia, and female genitalia—of the type specimen are exceedingly similar to the specimens listed below from Tena and El Pincho, Ecuador.

The allotype and two paratypes of Pseudodisersus coquereli Brown were borrowed for study from the British Museum (Natural History). The allotype is labeled as follows. (1) A rectangular card with one specimen pinned to it, the abdomen and female genitalia glued to the card, and “Bogota” handwritten in ink on its base. (2) A round white label with a yellow rim: “Paratype” printed in the middle. (3) A white rectangular label: “Sharp Coll./1905-313.” (4) A green, folded, rectangular label: “Ancyronyx/goudotii guer./Bogota.” (5) A white rectangular label: “Pseudodisersus/coquerel Brown/ det. H. P. Brown.” (6) A rectangular pink label: ALLOTYPE.

The paratypes are labeled as follows. (1) An almost square card bearing two specimens pinned into the card and “Bogota” handwritten across the base of the card. (2) A round white label with yellow rim and “Paratype” printed in middle. (3) A white rectangular label: “Sharp Coll./1905-313.” (4) A white rectangular label: “Pseudodisersus/coquerel Brown/ det. H. P. Brown.” (5) A rectangular pink label: “PARATYPE.” Both specimens are males. The specimen on the right side of the card was dissected and we attached the genitalia with water soluble glue on the card below the dissected specimen. These three specimens are conspecific with Pseudodisersus goudotii, therefore, we place P. coquereli in synonymy under P. goudotii.

ADDITIONAL SPECIMENS EXAMINED.—COSTA RICA. SANJOSE: Rio Union and Pan Am Hiway, 22 Jun 1972, C.L. Hogue, 1 (LACM). ECUADOR. NAPO: Tena (17 km SW), 28 May 1977, P.J. Spangler and D.R. Givens, 1, 2. MORONA-SANTIAGO: El Pincho (3 km E), 30 Nov 1978, J.J. Anderson, 1. ZAMORA-CHINCHIPE: Zumbi (14.4 km S), 4 Nov 1979, J.J. Anderson, 5, 3. PANAMA. CHIRIQUI: Volcan (19 km W), 3 Jun 1983, P.J. Spangler, R.A. Faitoute, W.E. Steiner, 32, 21.

HABITAT.—The specimens from Tena, Ecuador, were collected by hand-picking submerged beetles from rocks in riffles of a small, shaded stream in the forest. The stream was about 5 meters wide and contained some pools that were up to 1 meter in depth. Those from Panama were collected from their resting places on the rock face of a small, 1½ m high, waterfall in a cascade. Those specimens were collected by dislodging them by hand and allowing the current to wash them into an aerial insect net. The cascade was about ½m wide and ½ cm deep over the rock surface.

LARVA (Figures 125, 126).—Body elongate ovate; moderately flattened ventrally; moderately convex dorsally; subtriangular in cross section. With three scar-like depressions on each side of midline from pronotum to first abdominal tergum. Margins of mesothoracic, metathoracic, and abdominal segments expanded laterally very narrowly.

Head, when seen from above, not concealed by pronotum; anterior margin toothed between base of antenna and clypeus. With a cluster of 5 ocelli on each side. Frontoclypeal suture well developed. Labrum with dense fringe of long recurved setae anteriorly. Antenna, 3 segmented. Mandibles symmetrical; with 3 obtuse apical teeth; prostheca long, slender, and densely hirsute. Maxillary palpus, 4 segmented; stipes without palpifer; galea and lacinia separate and apex of each densely spinose. Labium with postmentum undivided. Labial palpus, 2 segmented; prementum with a palpiger. Gula well developed.

Prothorax ventrally as follows. Cervical sclerite medial, small, triangular. Prepleurite long in front of coxal cavities; postpleurite divided into 2 sclerites. Posterior sternum absent thus procoxal cavities open posteriorly. Mesosternum and metasternum each with 2 pleural sclerites.

Abdominal sterna with sternopleural sclerites on segments 1–5 and a partial suture on segment 6; segments 7 and 8 forming completely sclerotized rings; segment 9 tectiform. Abdominal terga without tergopleural sclerites. Ninth abdominal segment with apex deeply emarginate; apicolateral angles with acute, tooth-like projections; midline moderately ridged dorsally. Operculum ovate tapering to an obtuse apex.

Spiracles present on mesothorax and first 8 abdominal segments; opening on small tubercles.

The specimen described is identified as the larva of Pseudodisersus goudotii by elimination of Disersus, the only other known Andean laraine of similar size. The specimen is labeled: ECUADOR: PASTAZA: Puyo (16 kilometers west), 5 Feb 1976, P.J. Spangler et al.

Potamophilops Grouvelle, 1896

Potamophilops Grouvelle, 1896:78 [type-species: Potamophilus cinereus Blanchard, 1841:60; by monotypy].—Coquérel, 1851:598 [cites P. cinereus and repeats Blanchard's description, 1841].—Grouvelle, 1896:78 [description and in key to genera].—Zaitzev, 1908:288 [catalog, P. cinereus]; 1910:6 [catalog].—Blackwelder, 1944:272 [catalog, P. cinerea].—Bertrand, 1972:482 [in key to larvae].—Brown, 1981:77 [in key to genera].

DIAGNOSIS.—Body elongate, robust, densely pubescent. Labrum very broad, wider than clypeus. Antennae widely separated at base; each 11 segmented. Pronotum wider than long, narrowed anteriorly; with deep anterior, transverse impression across entire width; anterolateral and posterolateral angles obtuse; posterior margin moderately raised medially between sharply and broadly depressed posterolateral angles (Figure 127). Prosternum not triangular, shallowly excavated, very short in front of procoxae; anterior margin not reflexed (Figure 128). Prosternal process parallel-sided between procoxae, with raised ligulate apex. Procoxae, mesocoxae, and metacoxae moderately broadly separated. Mesosternum with moderately broad, shallow, pubescent depression on posterior fourth to receive loose fitting apex of prosternal process. Metasternum with a narrow, median, longitudinal groove; disc broadly shallowly depressed on each side of midline, more pronounced on males. Legs long; tarsal claws robust, without teeth. Elytra elongate, not much broader across humeri than basal width of pronotum; apices rounded to slightly angulate and only slightly divergent at apex; without accessory striae; intervals only vaguely raised (Figure 129). Hind wings without radial cross-vein; with closed anal cell; vein 1A uninterrupted between crossvein cu-a and wing margin; veins 2A1 and 2A2 fused; vein 3A1 joining 2A3 on posterior margin of anal cell distal of base of cell. Abdomen of 5 visible segments; segments 1–4 progressively shorter (Figure 130). Male genitalia very elongate and slender; basal piece longer than median lobe; median lobe longer than parameres. Female genitalia with coxites short and broad; styli short.

The single species described in this genus, Potamophilops cinereus, is presently known to occur only in Argentina and Brazil (Figure 131).

Pseudodisersus goudotii (Guérin-Méneville)

Potamophilus goudotii Guérin-Méneville, 1843:18.—Coquerel, 1851:597.

Disersus goudotii.—Sharp, 1882:127.—Blackwelder, 1944:272.

Disersus goudoti.—Zaitzev, 1908:288; 1910:7.

Pseudodisersus coquereli Brown, 1981a:100.

Pseudodisersus goudotii.—Spangler and Santiago, 1987:29.

DIAGNOSIS.—The single species known in the genus; may be distinguished by its large size and the distinctive pronotal impressions described under the generic description (Figures 6, 171).

REDESCRIPTION (MALE).—Body Form and Size: Elongate, subparallel, moderately convex dorsally. Length, 6.58 mm; greatest width (across elytral humeri), 2.34 mm.

Color: Blackish brown dorsally. Antennal segments 1 and 2 reddish brown; antennal segments 3–11 black. Venter blackish brown except basal segments of all palpi; labium; maxillae; coxae; trochanters; and bases of femora, mesotibiae, metatibiae, and tarsi reddish brown.

Head: Finely, densely punctate; punctures separated by puncture diameter or less. Eyes large, hemispherical. Clypeus broadly emarginate anteriorly. Labrum (Figure 180) densely and moderately coarsely punctate; anterior margin unmodified, almost truncate, and densely fringed with long, fine, golden, hair-like setae; anterolateral angles rounded and only moderately expanded laterally. Maxillary palpus as illustrated (Figures 181, 182). Labial palpus as illustrated (Figures 180, 181, 183).

Thorax: Pronotum widest just before base; length, 1.39 mm; width, 2.13 mm; sides arcuate; anterolateral angles obtuse; with distinct constriction posterolaterad of each anterior angle; a deep transverse impression across apical fourth of pronotum; apex arcuate; base strongly sinuate; with a robust tubercle on each side of midline in front of scutellum; each tubercle preceded by a small gibbosity with a slight depression anterolaterally; posterolateral angle; surface with deep transverse impression across apical fourth; with sublateral, moderately deep impressions separating sublateral lobe from smaller basolateral lobe; midline longitudinally depressed behind transverse depression, more deeply so on basal half; discal area finely densely punctate, punctures separated by puncture diameter. Elytron 5.38 mm long, 1.17 mm wide; with striae coarsely punctate; punctures separated by 1–1 times puncture diameter; intervals very finely alutaceous and finely, densely punctate; punctures on intervals separated by distance equal to puncture diameter or less and obscured by dense pubescence; humeral area strongly tumid; sides of elytra distinctly rimmed and almost parallel; apex moderately dehiscent, evenly arcuate laterally and terminating in obtusely spinous apex (Figure 196). Prosternum short in front of procoxae; depressed medially. Prosternal process broadly V-shaped; base broadest; converging to narrowed but rounded apex; narrowed apical third flat. Mesosternum deeply and broadly excavated for reception of apex of prosternal process. Metasternum convex on each side of meson; deeply and broadly depressed posteromedially between metacoxae; surface microreticulate and punctate; punctures moderately coarse and sparse, separated by 1–2 times puncture diameter. Procoxae and metacoxae moderately widely separated; mesocoxae slightly more widely separated. Legs compressed dorsoventrally; profemora and mesofemora distinctly flattened. Mesotibiae with lateral surface finely alutaceous; without dense hydrofuge pubescence except a very small area at base and a narrow strip on medial (lower) and lateral (upper) surface. Metatibiae with lateral surface lightly, finely alutaceous; virtually impuncntate; with basal half densely pubescent and sharply delineated from glabrous area (Figure 192). Tarsal claws moderately long and very stout.


Abdomen: Sterna 1–4 becoming progressively shorter. Sternum 1 with distinct longitudinal carina extending from metacoxa almost to hind margin on each side of meson (Figure 175). Apex of sternum 5 rounded (Figure 193).

Genitalia: As illustrated (Figures 189, 190).

FEMALE.—Similar to male except metasternum less deeply and less broadly depressed on meson. Elytral apices slightly more produced (Figure 197) than those of male. Apex of abdominal sternum 5 subtruncate. Genitalia as illustrated (Figure 191).

VARIATIONS.—We have seen no variations except in size in the specimens we examined from our area of study. Males (n = 6) range in length from 5.52 to 6.58 mm (x = 6.21 mm); females (n = 6) range in length from 6.86 to 7.34 mm (x = 7.02 mm). All of the specimens have the elytral apices moderately dehiscent, evenly arcuate laterally, and terminated in evenly rounded apices. Some variation may be found eventually in Middle American specimens of this species for we have seen some specimens from Ecuador that have the elytral apices more dehiscent and terminating in more elongated apices.

TYPE DATA.—We have examined the female type that is in the Muséum National d'Histoire Naturelle, Paris, and is labeled: [1] “P./Goudoti/Guérin/Columbia”—a blue circular label. [2] “”—on a white rectangle. [3] “Museum Paris/Collection/Generale”—a light blue rectangle. [4] “Type”—a red rectangle.

SPECIMENS EXAMINED.—COSTA RICA: San José: Río Union and Pan Am[erican] Hiway, 22 Jun 1972, C.L. Hogue, 1 spm (LACM).

PANAMA: Bocas del Toro: Miramar, Laguna de Chiriquí, stream behind sawmill, above falls, 25°C, 2 May 1985, R.W. Flowers, 1 spm (NMNH). Chiriquĺ: Cuenca Fortuna, Quebrada Honda, 17 May 1985, R.W. Flowers, 1 spm (NMNH); Presa Fortuna, lt, 8 May 1985, R.W. Flowers, 2 spms (NMNH); Santa Clara, Hartmann's Finca, 15–18 Jun 1985, E. Riley, D. Rider, 2 spms (LSU); Volcán (19 km W), small brook at culvert, 3 Jun 1983, P.J. Spangler, R.A. Faitoute, W.E. Steiner, 53 spms (NMNH). San Blas: Campamento Nusagandi (2.5 km S), 1 May 1987, D. Quintero, H. Herrera, R. Cambra, 2 spms (UPan). Veraguas: Santa Fe, Quebrada Muela, 9 Aug 1987, R. Cambra, 2 spms (UPan); same data except R. Rodríguez, 1 spm (UPan).

DISTRIBUTION (Figure 198).—Pseudodisersus goudotii is presently known in Central America from Costa Rica and Panama and in South America from Colombia and Ecuador (Spangler and Santiago, 1987). In addition, the larva of Pseudodisersus keyed to Disersus by Hinton (1940a) extends the distribution of P. goudotii south to Bolivia.

Hispaniolara Brown, 1981

Hispaniolara Brown, 1981a:85 [type species: Hispaniolara farri Brown, 1981a:88; by original designation]; 1987:261.—Spangler and Santiago, 1987:4.

DIAGNOSIS.—Length, to 7.70 mm. Pronotum with transverse impression at apical third; without arcuate sublateral impressions and basomedial tubercles (Figures 7, 205). Mesofemur longer than greatest body width.

ADULT.—Body slender; widest at elytral humeri and apical fourth of elytra.

Head partly retracted into pronotum but not beyond eyes. Antenna short and compact, 11 segmented. Maxillary palpus, 4 segmented. Labial palpus, 3 segmented. Labrum transversely rectangular; apical margin almost truncate; anterolateral angles rounded; sides arcuate; surface densely pubescent.

Pronotum convex; widest at base; with subapical transverse impression; without longitudinal grooves or carinae; anterolateral and posterolateral angles obtuse; base trisinuate, broadly so on each side of and more narrowly so in front of scutellum. Hypomeron vertical. Scutellum flat, broadly triangular. Elytra with punctate striae; without accessory stria. Hind wing (Figure 199) without radial cross vein; with closed anal cell; anal vein 2 with branches 1 and 2 fused; anal vein 1 interrupted between cubito-anal cross vein and wing margin; cubito-anal cross vein joining cubitus to base of incomplete anal vein 1; anal vein 2 joining anal vein 3 before dividing. Prosternum in front of procoxae very short, about width of basal protarsal segment. Prosternal process broad and long; parallel sided between procoxae then converging to obtusely angular apex. Mesosternum transverse; with shallow groove for reception of apex of prosternal process. Metasternum subquadrate; disc moderately broadly concave posteromedially; with a fine, median, longitudinal, impressed line on posterior three-fourths. Epipleuron vertical to posterior margin of sternum 4 then inflexed horizontally.

Abdominal sternum 1 convex in both sexes; without carinae. Sternum 5 with apex obscured by hair-like setae in both sexes; distinctly and narrowly emarginate apicomedially in males and shallowly broadly emarginate in females.

LARVA (BY ASSOCIATION) (Figures 200, 201).—Length, 8.4 mm; greatest width, 1.90 mm. Body elongate, subovate; moderately convex dorsally; moderately flattened ventrally; subtriangular in cross section. With 4 longitudinal, sinuous rows of broad, ovate, yellowish setae on each side of meson of pronotum, mesonotum, and metanotum; each seta arising from a tubercle. Margins of all segments neither falcate nor explanate.

Head with cluster of 5 stemmata on each side; without tooth on anterior margin between base of antenna and clypeus. Antennae broken; only basal segment present (presumably 3 segmented). Frontoclypeal suture indistinct. Mandibles rigidly retracted, not dissected from unique specimen. Maxilla with palpus, 4 segmented; stipes without palpifer; galea and lacinia separate and apex of each densely spinose. Labrum with anterior margin broadly, shallowly emarginate; with an apical fringe of dense, short, stout setae. Labium with palpus, 2 segmented; prementum with a palpiger; postmentum undivided. Gula well developed.

Terga of all thoracic segments with 8 longitudinal rows of low tubercles bearing short, ovoid setae. Prosternum with episternum long and broad in front of coxal cavities; with epimeron divided into 2 sclerites; sternellum triangular; without posteromedial sclerite, thus procoxal cavities open posteriorly. Mesosternum and metasternum each with an episternal sclerite, a single epimeral sclerite, and an undivided sclerite in front of mesocoxae and metacoxae.

Abdomen with sternopleural sclerites on segments 1–7. Terga 1–8 each with 5 rows of seta-bearing tubercles on each side of meson similar to those on thorax.

Spiracles present apicolaterally on mesothorax and laterally on abdominal segments 1–8. Mesothoracic spiracles opening at surface. Spiracles on abdominal segments opening on large tubercles.

The larva described above is identified as the presumed larva of H. farri Brown because Brown collected it in association with the adults of that species and its large size eliminates it as the larva of any other elmids known from Hispaniola. The larval characters substantiate the premise that Hispaniolara is most closely related to the laraine genus Disersus.

The described larva, presumed to be a last instar, was collected with an adult paratype from the Dominican Republic, Río La Candango w. Bonao, elev. 1025 m, on 10 Oct 1971. We are indebted to Dr. Brown who kindly donated this larva to the National Museum of Natural History, Smithsonian Institution, and allowed us to include it in our study.