Hydrophilus (Dibolocelus) cf. purpurascens ( Régimbart, 1901 )

Arce-Pérez, Roberto, Arriaga-Varela, Emmanuel, Novelo-Gutiérrez, Rodolfo & Navarrete-Heredia, José L., 2021, Giant water scavenger beetles Hydrophilus subgenus Dibolocelus (Coleoptera Hydrophilidae) from Mexico with description of two new species, Zootaxa 5027 (3), pp. 387-407 : 403-404

publication ID

https://doi.org/10.11646/zootaxa.5027.3.5

publication LSID

lsid:zoobank.org:pub:0B8E6B3B-3F14-4959-AB39-ADF60E98EE43

persistent identifier

https://treatment.plazi.org/id/03FB87D9-FFCB-8631-5DFD-E65CFBDDF975

treatment provided by

Plazi

scientific name

Hydrophilus (Dibolocelus) cf. purpurascens ( Régimbart, 1901 )
status

 

Hydrophilus (Dibolocelus) cf. purpurascens ( Régimbart, 1901)

Figs. 23, 24 View FIGURES 19–24 ; 33–36 View FIGURES 25–36 , 42.

Dibolocelus palpalis var. purpurascens Régimbart, 1901: 223 .

Hydrous (Dibolocelus) palpalis var. purpurascens (Régimbart) ; Zaitzev, 1908: 367.

Hydrophilus palpalis s. purpurascens (Régimbart) ; Blackwelder, 1944: 171.

Dibolocelus purpurascens Régimbart ; Bachmann, 1969: 284.

Studied material (7♂, 4♀): Mexico: Veracruz: Alvarado, La Barranca, Rancho la Fiaca , 14.iv.2001, M . Aragón col. 1 ♂ ( IEXA) . Nicaragua: León, luz UV . 23.i.1993, Pogatshnik col 1 ♂; León , V-1988 , Maes col. 1 ♂, 1 ♀; León , III-1990 , Garcete col. 1 ♀; León , vi.1989 , Maes col. 1 ♀ ( IEXA) ; Río San Juan: Los Guatuzos, Río Papaturro , 40 m, UTM 16 P 0712685-1220212 , 17 / 24.iii.2000, Maes, Sunyer y Hernández cols. 2 ♂, 1 ♀; Río San Juan, San Carlos 21.ii.1995, F . Collantes col. 2 ♂.

Diagnosis. This species can be distinguished by the following combination of characters: Maxillary palpi robust, inflated, with third palpomere with a deep ventral excavation; anterior margin of mentum truncated and straight; anterior tibiae with a row of hard setae that form a subrectangular plate (comb-like) near the internal base ( Fig. 34 View FIGURES 25–36 ); fifth protarsomere about as long as basal ones together, slightly flattened, without laminar expansion. This species is very similar to H. (D.) pollens but can be distinguished by [the characters of H. (D.) pollens are provided in square brackets for comparative purposes] H. (D.) cf. purpurascens being dorsally dark green with purple reflections ( Fig.23 View FIGURES 19–24 ) [is dorsally black with greenish hue ( Fig. 21 View FIGURES 19–24 )]; anterior margin of mentum truncated and straight ( Fig. 33 View FIGURES 25–36 ) [anterior margin of mentum rounded ( Fig. 29 View FIGURES 25–36 )]; protarsal claws not expanded, only acute ( Fig. 34 View FIGURES 25–36 ) [claws expanded to 2/5 apical and apically acute ( Fig. 30 View FIGURES 25–36 )]; metaventral spine longer, reaches or exceeds the posterior margin of the third abdominal ventrite ( Figs. 24 View FIGURES 19–24 ) [the metaventral spine shorter, not exceeding 1/2 of the third abdominal ventrite ( Fig. 22 View FIGURES 19–24 )]; ventrites 4 and 5 with a thick and glabrous crest ( Fig. 35 View FIGURES 25–36 ) [ventrites 3 to 5 with a sharp and glabrous crest ( Fig. 31 View FIGURES 25–36 )]; parameres thick, slightly directed outward and with apex broad sub-triangular ( Fig.36 View FIGURES 25–36 ) [slender param- eres, slightly directed inward and with their apex truncated and directed inward ( Fig. 32 View FIGURES 25–36 )].

Description. Body elongated-fusiform, length 33–38 mm, width 17–18 mm at humeri, 2.0× longer than wide, dorsally strongly convex and glabrous, ventrally flat and pubescent. Dorsal color black with dark purple tone (purple tone was not observed clearly in old specimens), ventrally black with reddish hue, ventral vestiture pale yellow; antennae, yellow, palpi yellowish-red, legs black with reddish hue ( Figs 23, 24 View FIGURES 19–24 ).

Head: Antennae short with scape large and robust, slightly flattened, longer than the next four antennomeres together, pedicel subequal to the following three antennomeres together, sixth antennomere long and oval, with external margin subequal to the previous four together, almost completely covering the first article of antennal club. Maxillary palpi long and slender, with four palpomeres with lengths: 0.5, 2.8, 2.3, 2.1 mm; first palpomere small and globose, second robust, markedly curved and broadened towards apex, third globose, about 2.1× longer than wide, wider at basal third, with a deep and broad ventral excavation from base to near apex, fourth short, slender, subcylindrical, slightly curved and with truncated apex. Mentum hexagonal, 1.6× wider at base than long, lateral margins parallel, anterior margin slightly curved inwards, apex truncated and straight. Labial palpi short, length of palpomeres: 0.2, 1.7, 1.2 mm; first palpomere very small and broad, second long, inflated, sub-triangular and widening apically, 1.4× longer than the third, with a tuft of long golden setae near the outer margin, third palpomere shorter, comparatively narrow with truncate apex ( Fig. 33 View FIGURES 25–36 ).

Thorax: Prosternal lobes raised with apex with acute tooth directed ventrally, with short reddish-yellow setae near apex; mesoventrite with broad keel, with lateral margins slightly convergent towards apex, with a elongate-oval shallow concavity at basal 4/5, deeper towards apex. Metaventrite with keel wide and convex, with rounded lateral margins, ending as a long spine reaching the posterior margin of the third abdominal ventrite ( Fig. 24 View FIGURES 19–24 ). Each elytron with two well-marked rows of black spots, one sublateral starting after the humerus, and other more incomplete on the sides ( Fig. 23 View FIGURES 19–24 ).

Legs: Anterior tibiae with a row of hard setae that form a subrectangular plate (like comb) near the internal base; with internal one spur shortest, flat, sub-rectangular with truncate apex, external spur longer, sub-triangular, acute; fifth protarsomere about as long as basal ones together, slightly flattened, without projections; tarsal claws long, curved, without basal tooth, internal claw slightly longer than external one; protarsomeres 2, 3 and apex of 5 with tufts of golden setae in the external margin ( Fig. 34 View FIGURES 25–36 ).

Abdomen: Vestiture leaving a slender oval glabrous area at mid-line in ventrite 4, and broader sub-triangular one in ventrite 5. Ventrite 4 with a wide keel in the posterior 3/4 projecting over next ventrite as a short spine; ventrite 5 with a slightly acute keel along all its length at mid-line ( Fig. 24 View FIGURES 19–24 , 35 View FIGURES 25–36 ).

Genitalia: Total length 4.7 mm (holotype); phallobase long (length: 2.75 width 1.6) narrow with apex of manubrium rounded; parameres long (length: 3.2 mm), broadened at basal 3/5, and markedly narrowed at apical 2/5, slightly directed outward, with apex comparatively wide and subtriangular; median lobe elongate sub-triangular, slightly shorter than the parameres (2.65 mm), apex rounded with an elongate sclerite at mid-line ( Fig. 36a, b View FIGURES 25–36 ).

Sexual dimorphism. Females similar to males but with narrow maxillary palpi, third labial palpomere not inflated nor excavated, protibiae with internal spine not truncate, acute, slightly shorter than external. Tarsal claws curved and acute with an acute basal tooth.

Distribution: Costa Rica, Guyana, Mexico: Veracruz, Nicaragua: León, Río San Juan and Venezuela (Arce- Pérez & Morón 2013; Bachmann 1969; Maes 1989) (Distribution in Mexico: Fig. 42).

M

Botanische Staatssammlung München

UV

Departamento de Biologia de la Universidad del Valle

F

Field Museum of Natural History, Botany Department

Kingdom

Plantae

Phylum

Tracheophyta

Class

Liliopsida

Order

Poales

Family

Restionaceae

Genus

Hydrophilus

Loc

Hydrophilus (Dibolocelus) cf. purpurascens ( Régimbart, 1901 )

Arce-Pérez, Roberto, Arriaga-Varela, Emmanuel, Novelo-Gutiérrez, Rodolfo & Navarrete-Heredia, José L. 2021
2021
Loc

Hydrophilus palpalis

Blackwelder, R. E. 1944: 171
1944
Loc

Hydrous (Dibolocelus) palpalis var. purpurascens (Régimbart)

Zaitzev, F. A. 1908: 367
1908
Loc

Dibolocelus palpalis var. purpurascens Régimbart, 1901: 223

Regimbart, M. 1901: 223
1901