Megadytes (Bifurcitus) ducalis Sharp, 1882

Hendrich, Lars, Manuel, Michael & Balke, Michael, 2019, The return of the Duke - locality data for Megadytes ducalis Sharp, 1882, the world's largest diving beetle, with notes on related species (Coleoptera: Dytiscidae), Zootaxa 4586 (3), pp. 517-535 : 518-523

publication ID

https://doi.org/ 10.11646/zootaxa.4586.3.8

publication LSID

lsid:zoobank.org:pub:3CFD2CE3-6E93-4DFB-81CB-5406DB34BF2C

persistent identifier

https://treatment.plazi.org/id/082F1226-FFB2-FFE4-C1B0-6953FE464E18

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Plazi

scientific name

Megadytes (Bifurcitus) ducalis Sharp, 1882
status

 

Megadytes (Bifurcitus) ducalis Sharp, 1882 View in CoL

Megadytes ducalis Sharp, 1882: 713 View in CoL (orig. descr.); Zimmermann 1920: 256; Blackwelder 1944: 80. Megadytes (Bifurcitus) ducalis Sharp, 1882 View in CoL ; Brinck 1945: 8; Trémouilles 1989b: 153; Miller & Bergsten 2016: 108; Nilsson & Hájek 2019: 80.

Type locality. Brazil .

Type material examined. Holotype , male (BMNH): " Brazil, Saunders ", " Type ", " Megadytes ducalis Sharp ".

Other material examined. Brazil: 1 male, 1 female, " San Antônio da Barra [= Condeúba, City Center is at - 14.899° -41.968°, 660 m], Prov. de Bahia, Brésil" ; 1 female, " S. Antonia da Barra pr. de Bahia Gounelle 11.12.1888 " [printed label] ; 1 female, "S. Antonia da Barra pr. De Bahia CH Pujol 1890" [printed label] (MNHN- CR, drawer 60) ; 1 female, " Bahia Brésil " ; 1 male, "S. Antonia da Barra Pr. de Bahia Gounelle 11.12.1888 " [printed label] ( MNHN-CG, drawer 92) ; 1 male, "Museum Paris Brésil Coll. E. Gounelle 1915" [green printed label]

[among indet. material in separate drawer]; 1 female, " Brésil Bahia intr" [printed label], " ducalis Sharp " [handwritten label] ( MNHN-CW) ; 1 female " Cybister giganteus Brésil " [handwritten label] ; 1 female, "Museum Paris Brésil Coll. E. Gounelle 1915" [green printed label], " Megadytes ducalis Shp. San Antonio da Barra " [handwritten label] (MNHN-Magasin) .

Descriptive notes. Large beetle (TL> 42.9 mm) of very robust and "thick" appearance ( Fig. 2A View FIGURE 2 ). Descriptions of this species, based on the male holotype, were provided by Sharp (1882) and Trémouilles (1989). Here we provide photos of the habitus ( Figs 1A, D View FIGURE 1 , 2A View FIGURE 2 , 3 View FIGURE 3 ) and focus on morphological characters of the male in different views ( Figs 7 View FIGURE 7 A–E).

The median lobe, with both parameres, of a male from Coll. Guignot is figured in ventral view ( Fig. 4A View FIGURE 4 ), the anterior half of the median lobe in lateral view ( Fig. 4B View FIGURE 4 ) and the tip of the median lobe in dorsal view ( Fig. 4C View FIGURE 4 ). The median lobe of the holotype is presented in Fig. 4D View FIGURE 4 . It appears much broader than in the other specimens we studied. This is apparently due to manipulation by previous researchers, perhaps J. Balfour-Browne, whereby cardboard wedges were inserted in between the main lobe and the ventral sclerite to expose the latter. This is actually seen in several other Megadytes specimens in the BMNH collection, and can lead to significant changes to the shape of the median lobe.

Female. No traces of elytral striae or any other kind of sexual sculpture on pronotum or elytra. Without protarsal disks and yellow setae on ventral surface of mesotarsomere I; otherwise no external difference with male. Broadest part of femur in hind legs 5.3 mm ( Figs 1A View FIGURE 1 , 7E View FIGURE 7 ).

Measurements, holotype: TL = 47.2 mm; TL-H = 44.1 mm; TW = 26.4 mm. Additional specimens, males: TL = 42.9–47.0 mm; TL-H = 41.3–43.8 mm; TW = 25.1–25.9 mm. Females. TL = 43.5–47.4 mm; TL-H = 40.7– 44.1 mm; TW = 24.0–26,1 mm.

Note. The largest known specimen of M. ducalis (female, TL= 47.4 mm) is deposited in the collection of Maurice Régimbart in the Muséum National d'Histoire Naturelle in Paris ( Fig. 3 View FIGURE 3 ).

Distribution. Only known from Condeúba, Bahia, Brazil ( Fig. 11 View FIGURE 11 ).

Habitat. Unknown.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Dytiscidae

Genus

Megadytes

Loc

Megadytes (Bifurcitus) ducalis Sharp, 1882

Hendrich, Lars, Manuel, Michael & Balke, Michael 2019
2019
Loc

Megadytes ducalis

Nilsson, A. N. & Hajek, J. 2019: 80
Miller, K. B. & Bergsten, J. 2016: 108
Brinck, P. 1945: 8
Blackwelder, R. E. 1944: 80
Zimmermann, A. 1920: 256
Sharp, D. 1882: 713
1882
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