Hydrophilus (Dibolocelus), 1891

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 : 405

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-FFC9-8632-5DFD-E2B4FA1CF92D

treatment provided by

Plazi

scientific name

Hydrophilus (Dibolocelus)
status

 

Key for the species of Hydrophilus (Dibolocelus) from Mexico and Central America

Note. The first characters to appear in the couplets are those shared by both sexes when available. However, the best characters for specific identification are those found in male specimens. We recommend following this key with caution if only female specimens that are not associated to males are available.

1. Sixth antennomere long and oval, yellowish brown, almost completely covering the first article of antennal club ( Figs. 23 View FIGURES 19–24 , 33 View FIGURES 25–36 ); abdominal ventrites with vestiture leaving a slender oval glabrous area at mid-line in ventrite 4 and broader sub-triangular one in ventrite 5 ( Figs. 31, 35 View FIGURES 25–36 ) in both sexes. Males with robust (inflated) maxillary palpi, third palpomere with a deep broad ventral excavation ( Figs. 29, 33 View FIGURES 25–36 ), females with narrow palpi, without ventral excavation................................... 2

1’ Sixth antennomere short and oval, dark brown, not covering the first article of antennal club ( Figs. 7, 11 View FIGURES 7–18 , |5, 25); abdominal ventrites with vestiture leaving a wide oval glabrous area at mid-line in ventrites 3–4; and a broader sub-rectangular one in ventrite 5 in both sexes ( Figs. 2, 4, 6 View FIGURES 1–6 ); males with maxillary palpi narrow ( Fig. 25 View FIGURES 25–36 ) or slightly flattened towards apex ( Figs. 7, 11, 15 View FIGURES 7–18 ) in both sexes.................................................................................. 3

2 (1). Anterior margin of mentum truncated and straight in both sexes ( Fig. 33 View FIGURES 25–36 ); male genitalia with broad parameres, slightly directed outward, with broad subtriangular apex ( Fig. 36 a, b View FIGURES 25–36 )........................... H. (D.) cf. purpurascens Régimbart

2’ Anterior margin of mentum rounded, unknown female ( Fig. 29 View FIGURES 25–36 ); male genitalia with parameres comparatively narrow, markedly directed inwards, with slender round apex. ( Fig. 32 a, b View FIGURES 25–36 )................................. H. (D.) pollens Sharp

3 (1’). 3 (1’). Male with maxillary palpomeres 2 and 3 distinctly flattened and wide towards apex ( Figs. 7, 11 View FIGURES 7–18 ), slightly flattened in female; male with anterior tibiae internal spur sub-rectangular and with apex truncate ( Figs. 8, 12 View FIGURES 7–18 ), sub-triangular and acute in female.............................................................................................. 4

3’ Male and female with maxillary palpomeres 2 and 3 distinctly slender, only slightly flattened ( Figs. 15 View FIGURES 7–18 , 25 View FIGURES 25–36 ); males with anterior tibiae internal spur sub-rectangular with apex truncate straight ( Fig. 16 View FIGURES 7–18 ) or markedly bifid ( Fig. 26 View FIGURES 25–36 ).................... 5

4 (3). Metaventral spine short, not surpassing the posterior 3/4 of second abdominal ventrite ( Figs. 4 View FIGURES 1–6 , 13 View FIGURES 7–18 ); third palpomere very wide and flattened with its inner margin slightly curved ( Fig. 11 View FIGURES 7–18 ). Males with fifth protarsomere somewhat flattened with a small internal laminar expansion, shorter than previous tarsomeres together ( Fig. 12 View FIGURES 7–18 );............ H. (D.) pseudovatus sp. nov.

4’ Metaventral spine long, surpassing the posterior margin of second abdominal ventrite ( Figs. 2 View FIGURES 1–6 , 9 View FIGURES 7–18 ); third palpomere slightly wide and flat, compared to H. (D.) pseudovatus , with its inner margin slightly straight ( Fig. 7 View FIGURES 7–18 ). Males with fifth protarsomere subcylindrical, without a laminar expansion, longer than previous tarsomeres together ( Fig. 8 View FIGURES 7–18 ).............................................................................................. H. (D.) ovatus Gemminger & Harold

5 (3’) Males with fifth protarsomere as long as the basal together, flat and with evident internal laminar expansion; internal spur of anterior tibiae of males sub-rectangular with apex truncate ( Fig. 16 View FIGURES 7–18 )....................... H. (D.) nucleoensis sp. nov

5’ Males with fifth protarsomere shorter than previous tarsomeres together, wide and without internal expansion; internal spur of anterior tibiae of males with bifid apex ( Fig. 26 View FIGURES 25–36 )............................ H. (D.) violaceonitens Jacquelin du Val

Kingdom

Plantae

Phylum

Tracheophyta

Class

Liliopsida

Order

Poales

Family

Restionaceae

Genus

Hydrophilus