Diomus sekerkai González & Větrovec, 2021

González, Guillermo & Větrovec, Jaroslav, 2021, New species and records of Neotropical ladybirds (Coleoptera: Coccinellidae), Revista Chilena de Entomología (Rev. Chil. Entomol.) 47 (2), pp. 331-374 : 357-359

Diomus sekerkai González & Větrovec , new species

( Figs. 7 a-7l)

Holotype ♂ “ PANAMA, Panamá prov., / Cerro Campana , 850-1030m, / 08°41.324’N 79°55.314’W, / 12.v.2015, individual collecting, / L. Sekerka & K. Štajerová lgt”, “ ♂ 2050” ( NMP).

Diagnosis (male). Diomus sekerkai n. sp. has a yellowish brown head and thorax, and entirely black elytra ( Fig. 7a ). This combination of colors is quite common in the genus.

The male genitalia are the only sure character to identify this species. It is characterized by a single lateral tooth near the penis guide apex (this character immediately differentiates it from D. chiriqui n. sp. and D. panamensis n. sp.), penis guide slightly shorter than the paramere, absence of a dorsal keel in the penis guide, short and sparse pubescence in its inner distal part, and long and dense pubescence in the inner distal 1/3 of the paramere, a unique combination of characters in Diomus .

Description. Color pattern (male) ( Figs. 7 a-7d). Head entirely yellow, including antenna and mouthparts. Pronotum yellow. Scutellar shield and elytra black with dark brown epipleuron. Ventral side yellow, except mesoventrite, metaventrite and abdomen brown. Legs yellow. Pubescence whitish. Morphology. Body oval, wide, elytra with sides regularly curved, widest anterior to middle of elytra ( Fig. 7a ). Frons about 1.5 times the width of an eye. Eyes oval, 1.5 times longer than wide. Very small eye canthus. Clypeus apex slightly convex ( Fig. 7c ).Antennae with eleven antennomeres, club weakly defined.Apical maxillary palpomere securiform.Prosternum Y-shaped, short. Abdominal postcoxal lines incomplete, extended to hind margin of ventrite, evenly rounded ( Fig. 7e ). Tarsus trimerous. Head punctures small, not very apparent, space between punctures about twice the diameter; on the pronotum greater than those of the head, separated by 1.5 diameters on average; elytra punctures similar in size to those on pronotum, separated by 1/2 diameter on average; ventral side punctures abundant in the metaventrite, separated by about a diameter; abdominal punctures notorious at middle of ventrites 1 and 2, smaller towards the borders and posterior ventrites, very sparse in the postcoxal plate. Pubescence short, abundant, decumbent; on pronotum and elytra short, 1/3 of the length of the scutellar shield; on ventral side scarce, present mainly at the borders on mesoventrite and metaventrite; on abdomen long and quite dense on the lateral borders of ventrites 3 to 5, very short over ventrite 6, little perceptible in the rest of the abdomen. Male terminalia. Apex of ventrite 5 almost straight in the central 2/3, apex of ventrite 5 convex, slightly truncate medially ( Figs. 7 e-7f). Tegmen twice as long as wide, phallobase shorter than wide, transverse. Tegminal strut slightly shorter than the rest of the tegmen. Penis guide asymmetric, 2.5 times longer than wide, sides divergent and concave from the base to 3/4 of the length, where it is almost twice as wide as basally, apex rounded, the left side very curved especially in the distal third, concave right side, where it has a small tooth separated from the rest of the penis guide; in lateral view like a regular acute triangle with only a small curvature at the apex, it does not have a dorsal keel, scant and short dorsal pubescence. Parameres the same length as the penis guide, very elongated paddle-shaped, quite straight, with long inner hairs in the apical half, also abundant lateral pubescence, exceeding the paramere by 3/4 of the length ( Figs. 7 g-7j). Penis curved in a semicircle in the basal half, then almost straight up to the apex, which occupies the apical 1/6, spindle-shaped, in the very narrow outer part it remains sclerosed, while the inner side is membranous; penis capsule subrectangular, outer arm at 45 ° with respect to the penis tube, very large, sub-square, inner arm very small, hook-shaped, inclined towards the tube, basal margin sinuous, accessory piece absent (Figs. k-l). Female. Unknown.

Measurements (mm): TL 1.6; PL 0.4; PW 0.95; EL 1.2; EW 1.25; GD 0.9.

Geographic distribution. Panama, Panama province.

Remarks. For an analysis of the taxonomic status of the genus Diomus in America, see discussion under D. chiriqui sp. n. The characters mentioned there for the genus are found in the present species, including the descending incomplete postcoxal lines, the trimerous tarsi, the short antenna of eleven antennomeres and the apical maxillary palpomere securiform, as well as the asymmetric male penis guide. This species is placed in species group “C” as defined in Gordon (1999) by the presence of a tooth in the penis guide ( Figs. 7 i-7j).

Etymology. The species is dedicated to Lukas Sekerka, specialist in Chrysomelidae of the Department of Entomology, National Museum, Prague, Czech Republic, collector of this and other new species that are described in this study.

Figures

Figures 7a-7w. a-l: Diomus sekerkai n. sp.; a-d: habitus male (dorsal, lateral, frontal, posterior); e: abdomen; f: ventrite 6; g-h: tegmen; i-j: penis guide; k-l: penis and detail. m-w: Toxotoma venezuelae n. sp.; m-p: habitus (dorsal, lateral, frontal, posterior); q: abdomen; r: ventrite 6; s-t: tegmen; u: penis guide; v-w: penis and detail. Scale bars in mm. / a-l: Diomus sekerkai sp. n.; a-d: habitus del macho (dorsal, lateral, frontal, posterior); e: abdomen; f: ventrito 6; g-h: tegmen; i-j: guÍa del penis; k-l: penis y detalle. m-w:Toxotoma venezuelae sp. n.; m-p: habitus (dorsal, lateral, frontal, posterior); q: abdomen; r: ventrito 6; s-t: tegmen; u: guÍa del penis; v-w: penis y detalle. Escalas en mm.