Biodontocnema, Biondi, Maurizio, 2000

Biondi, Maurizio, 2000, Biodontocnema Brunnea New Genus And New Species From South Africa (Coleoptera: Chrysomelidae: Alticinae), The Coleopterists Bulletin 54 (3), pp. 347-350 : 347-350

Biodontocnema , new genus

Figs. 1–3, 5, 7–9

Diagnosis. Apex of external dorsal margin of hind tibiae bidentate (Fig. 3); antennae with segments 7–11 short and enlarged; interantennal space very wide; 3 rd tarsomere of all legs very narrow; unguiculi basally slender (basally thicker in Chaetocnema ) (Figs. 4–5); frontal tubercles large, very weakly delimited; procoxal cavities half­closed (Fig. 2); metafemoral spring ( Fig. 9 ) attributable to Chaetocnema morpho­group (cf. Furth and Suzuki 1998), with extended arm of dorsal lobe short and depressed, ventral lobe with no recurved flange and with dorsal edge straight and strongly angled down apically.

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Biodontocnema brunnea , new species Figs. 1–3, 5, 7–9

Description of Male Holotype. Body shape elongate­elliptical (Fig. 1), moderately convex (LB = 2.19 mm). Dorsal integument dark reddish brown, blackish on elytral

disc, with weak metallic reflection. Maximum pronotal width near base: 0.96 mm; maximum elytral width in basal third: 1.12 mm.

Head with weakly impressed punctation on vertex and frons, mostly subrugose on interocular space; frontal tubercles large, subtriangular, dorsally not well delimited; frontal carina absent; interantennal space very wide, with weakly impressed large punctures; labrum subrectangular, reddish, with six preapical setae; palpi reddish yellow; antennae short (LAN/LB = 0.46) with segments 1–5 yellowish, 6–11 brownish; length of each antennal segments proportional to numerical sequence 12:6:6:5:6:5:6:6:6:6:11 (1 = 0.01 mm).

Pronotum clearly transverse ( LP = 0.56 mm; WP / LP = 1.71), laterally mostly straight and convergent from base to apex; margins, mainly laterally, clearly bordered; anterior angles slightly raised, apically rounded; punctation distinctly impressed and uniformly distributed on almost smooth surface. Elytra elongate ( LE = 1.71 mm; LE / LP = 3.05), entirely covering pygidium; laterally weakly but regularly rounded; punctation mostly arranged in 9 striae (+ 1 scutellar interrupted at basal third), confused on disc with evident punctation of interstriae; humeral callus absent; wing type subbrachypterous. Scutellum subtriangular with finely shagreened surface .

Ventral surface pale brown. Prosternal process dark brown, enlarged at posterior end (Fig. 2). Last sternite with large points weakly impressed on smooth surface, without special preapical impressions. Legs entirely yellowish; hind femora strongly enlarged; apical spur of hind tibiae elongate (Fig. 3), dark brown; 1 st anterior and middle weakly dilated. Median lobe of aedeagus thickset (LAED = 1.07 mm; LE/LAED = 2.17) ( Fig. 7 ), yellowish, superficially smooth; laterally parallelous and apically mostly rounded; ventral sulcus very slightly impressed; dorsal sulcus visible in apical half; dorsal ligula elongate, little sclerified; median lobe in lateral view regularly curved with apex ventrally bent.

Variability. Males (n = 3): LB = 2.08 ± 0.15 mm; LAN = 0.98 ± 0.03 mm; LP = 0.58 ± 0.04 mm; WP = 0.94 ± 0.09 mm; LE = 1.62 ± 0.13 mm; WE = 1.08 ± 0.06 mm; LAED = 0.74 ± 0.03 mm; LAN/LB = 0.47 ± 0.02; WP/LP = 1.63 ± 0.03; LE/LP = 2.79 ± 0.02; LE/LAED = 2.18 ± 0.08. Females (n = 1): LB = 2.40 mm; LAN = 0.90 mm; LP = 0.64 mm; WP =

1.09 mm; LE = 1.97 mm; WE = 1.27 mm; LSP = 0.32 mm; LAN/LB = 0.38; WP/LP = 1.71; LE/LP = 3.08; LE/LSP = 6.17.

Females with 1 st anterior and middle tarsomere narrower; size little bigger (LB = 2.40 mm); spermatheca (LSP = 0.32 mm; LE/LSP = 6.17) ( Fig. 8 ) with basal part elongate, slightly reniform, and distal part moderately elongate not apically enlarged; ductus little elongate, dorsally starting, sinous.

Distribution. Republic of South Africa (Northern Cape Province).

Host Plants. Unknown.

Habitat. An assumption can be made about the type of habitat where this new species was collected considering the geographical position of the locality ‘‘Karos’’. This locality is placed in a vegetational transition area characterized by the ‘‘Bushveld’’ (northwards) and the ‘‘Karoo’’ (southwards) (cf. Acocks 1988). But because of the proximity of the Orange River, the possibility for a riparian environment cannot be excluded.

Etymology. This species name refers to color of its integument.

Type Series. Holotype male: Republic of South Africa (K S.W.A. k), Northern Cape Province, Karos (K Kaross k), Mus. Exped., Feb. 1925 (deposited SAMC) . Paratypes: 3 males and 1 female, Republic of South Africa (K S.W.A. k), Northern Cape Province, Karos [28.25S 21.34E] (K Kaross k), Mus. Exped., Feb. 1925 (deposited SAMC) .

Figures

Figs. 7–9. Biodontocnema brunnea: 7) Median lobe of aedeagus in lateral, ventral and dorsal view (LAED = 1.07 mm); 8) spermatheca (LSP = 0.32 mm); 9) metafemoral spring in anterior (a) and posterior (b) view.