Pygodiscodon obscurus Wittmer 1966
Creators: name: Biffi, Gabriel
name: Constantin, Robert
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Cantharidae
Pygodiscodon
Pygodiscodon obscurus

description: Pygodiscodon obscurus Wittmer, 1966 stat. restit.
(Figs 4, 10, 14–16, 26–28, 38, 50–52)
Pygodiscodon obscurum Wittmer, 1966: 411 (original description); DELKESKAMP (1977): 245 (catalogue); CONSTANTIN (2010a): 40 (distribution), CONSTANTIN (2010b): 12 (as synonym of P. apicicorne (Pic, 1910)).
Type locality. Brazil, Pará, Belém (‘Utinga bei Belém’).
Type material examined. HOLOTYPE:, ‘ Brasilien | Utinga bei | Belém / Pará | 17.X.1962 | C. Lindemann || 235 || Holotype || Pygodiscodon obscurum Wittm. | det. W. Wittmer’ (ZSMC).
Additional material examined. PARÁ: Belém-Marituba, 10.vi.1961, 1, J. & B. Bechyné leg. (MPEG); same locality, 24.x.1961, 2 1 ♀, J. & B. Bechyné leg. (1 1 ♀ MZSP, 10253–10254, 1 MPEG); Belém- -Instituto Agronômico do Norte, 10.xii.1960, 1, J. & B. Bechyné leg. (MPEG), 2.viii.1962, 1 1 ♀, J. Bechyné leg. (MZSP, 10255–10256), 17.x.1962, 1, J. & B. Bechyné leg. (MZSP, 10257); Belém-Mocambo, 17.iii.1977, 1, N. Guimarães leg. (MPEG), 24.xi.1977, 1, 6.ix.1978, 1, 21.ix.1978, 1, M. F. Torres leg. (MPEG), 28.xi.1977, 1, M. F. Torres leg. (MZSP, 10258); Belém-Utinga, 30.xii.1960, 1 ♀, J. & B. Bechyné leg. (MPEG); Benevides, 15.vi.1961, 1, J. & B. Bechyné leg. (MPEG); Santa Isabel do Pará, 30.iii.1962, 1, J. Bechyné leg. (MZSP, 5173).
Description. Body length: 5.1–6.3 mm. Head black; frons, clypeus and base of mandibles light brown to testaceous, slightly translucent; apex of mandibles light brown; palpi dark brown. Antennae black; first antennomere slightly lighter ventrally and antennomeres IX–X yellowish-white. Pronotum pale yellow with wide medial black patch stretching longitudinally from anterior to posterior margins. Elytra dark brown; legs light brown, darker from middle of tibiae, thorax and abdomen dark brown.
Male (Fig. 4). Head as long as wide, broadly rounded behind eyes, densely pubescent; occipital region and frons convex; clypeus wide, emarginated anteriorly. Eyes rounded, rather prominent. Maxillary palpi elongate, last palpomere slender and slightly securiform. Antennae (Fig. 10) long, serrate and compressed dorso-ventrally; dorsal surface of antennomeres IV to VI (sometimes also III and VII) with irregular longitudinal line, not straight, varying in length and width. Pronotum densely pubescent, transverse, 1.6 times wider than long; lateral margins slightly emarginated, explanate upwards and shortly notched before basal angles. Elytra finely rugous, densely covered with erect brownish setae; each elytron 4.5 times longer than wide. Legs slender; tarsomeres increasing in size from pro- to metathoracic legs; inner claw of prothoracic legs (Fig. 15) broadly lamellate at base; meso- and metathoracic tarsal claws with sharp protruding tooth (Fig. 16). Last abdominal ventrite (Fig. 26) bilobed, broadly rounded posteriorly; abdominal tergite VIII (Figs 26–28) elongate, with shallow latero-posterior compressions and strongly constricted posteriorly forming narrow apical projection bearing two contiguous glandular openings at apex; dorsal surface of apical projection with short protuberance. Aedeagus (Figs 50–52): ventral wall of tegmen long and broad, lateral sides slightly convergent, apical margin rounded with short median incision; short setae along lateral and apical margins and in narrow longitudinal fringe ventrally; parameres very short, slightly surpassing dorsal margins of tegmen; apex obtuse, bearing a few long setae; median lobe broad and membranous, longer than internal sac; internal sac short, hidden inside median lobe, except for pair of sclerites; dorsal sclerites strongly flattened laterally, apex truncate, projecting dorso-laterally; ventral sclerites longer, flattened laterally, tips pointing laterally.
Female. Similar to male but antennae lacking longitudinal lines; pronotum not notched laterally; tarsal claws simple; abdominal ventrite VII (Fig. 38) 1.6 times wider than long, not divided, lateral margins arched, distal margin with small projecting tip; abdominal tergite VIII broad and simple.
Differential diagnosis. Similar to P. apicicornis and P. similis sp. nov. Last abdominal ventrite of males bilobed, with rounded apex; last abdominal tergite of males similar to P. apicicornis, with shallow latero-posterior compressions and strongly constricted posteriorly, forming longer and narrower apical projection; dorsal surface without ridges, apical tooth shorter and rounded.
Distribution. Brazil, Pará state. All examined specimens were collected in the type locality or its surroundings (Fig. 59).
Remarks. CONSTANTIN (2010b) compared the syntypes of P. apicicornis (Pic, 1910) with the holotype of P. obscurus Wittmer, 1966 and found no significant differences between them, thus proposed the synonymy. Here the holotype of P. obscurus was re-examined and a greater quantity of specimens from the type locality was dissected and compared with specimens of P. apicicornis, showing constant morphological differences in the aedeagus and abdominal tergite VIII of males and abdominal ventrite VII of males and females. Such differences support the revalidation of P. obscurus as a valid species.
description: Published as part of Biffi, Gabriel & Constantin, Robert, 2018, Taxonomic revision of Pygodiscodon (Coleoptera: Cantharidae), pp. 77-90 in Acta Entomologica Musei Nationalis Pragae 58 (1) on page 85, DOI: 10.2478/aemnp-2018-0008, http://zenodo.org/record/3676782