Toxotoma venezuelae 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 : 359-361

Toxotoma venezuelae González & Větrovec , new species

( Figs. 7 m-7w)

Holotype ♂ “ Venezuela / Est. Barinas / V. Tichý lgt.”, “ Santo Domingo / 22.1.1996 / 2200 m. n. m.”, “ ♂ 1915” ( NMP).

Paratypes (total 2 specimens): 2 ♂ same data as holotype ( NMP) .

Diagnosis. This species can be distinguished by the male genitalia which presents a very long, parallel-sided penis guide, abruptly narrowed in the distal apex, with a small nipple-shaped projection in the center, while the penis is smoothly curved in the basal half, then bent upward to apex, as only occurs in the Epilachna angustata species group as defined by Gordon (1975); there are also characters of this species group present in Toxotoma venezuelae n. sp., the strongly bilobed labrum and the mandibles with the teeth grouped in the distal third. The color black with a blue glow on dorsal and ventral sides, occasionally with two little yellow spots on each elytron, distinguishes this species from any other in the group, where the yellow spots are larger and cover most of the elytral surface.

Description. Color pattern ( Figs. 7 m-7p). Head black. Antenna yellow with four last antennomeres brownish-black, maxillary palpi yellow with apical palpomere brown, mandibles and other mouthparts reddish brown to black. Pronotum black, anterior half of lateral borders and anterior angles light yellow. Scutellar shield black. Elytra black with blue dorsal luster, epipleuron black. Ventral side black, except anterior angles of hypomeron yellow, abdomen black. Legs black. Pubescence whitish. Morphology. Body oval elongate, elytra with regularly curved sides, widest at 1/5 the length of the elytra, narrowing at apical 1/3 ( Fig. 7m ). Frons more than twice width of an eye. Eyes oval, about 1.5 times longer than wide, inner border of the eye concave around the antennal insertion, without eye canthus. Clypeus apex slightly concave with rounded corners ( Fig. 7o ). Antenna with eleven antennomeres, the last three forming a club. Labrum strongly bilobed. Apical maxillary palpomere weakly securiform. Mandibles with three major teeth grouped in apical one-third, first tooth bidentate, their surfaces without tubercles. Prosternum Y-shaped, short and wide, without carinae. Metaventrite postcoxal lines transverse, not descending at lateral border. Abdominal postcoxal lines closed, slightly angulate, extended 2/3 the distance to apical margin of ventrite ( Fig. 7q ). Head punctures small but noticeable, disordered, space between punctures about ½ diameter; pronotum punctures larger than those of the head and dense, separated by ½ diameter on average; elytra densely punctured, of two types, the smallest similar to those of the pronotum, the largest twice as big, separated by 1/3 of the diameter on average; ventral side with few punctures, more abundant on the prosternum, separated by four times its diameter on the metaventrite; abdomen punctures heavy and coarse in the middle of ventrites 1 and 2, smaller towards the borders and posterior ventrites, very sparse in the postcoxal plate. Pubescence long, abundant, decumbent, dorsal hairs half the length of the scutellar shield; ventral side pubescence long and quite dense on the lateral borders of ventrites 3 and 5, very short over ventrite 6, faint in the rest of the abdomen. Male terminalia. Ventrite 5 with a regularly concave apex. Ventrite 6 almost triangular, with a strong notch in the central 1/3 of the apex, which has borders with long and regular hairs ( Figs. 7 q-7r). Tegmen more than four times longer than wide, phallobase transverse, a little longer than wide. Tegminal strut shorter than half the length of the rest of the tegmen. Penis guide symmetrical, five times as long as wide, sides slightly divergent in the basal quarter, then parallel to fourfifths of the length, where they converge smoothly, in the apex they converge sharply and present a short nipple-shaped projection in the center; in lateral view penis guide curved towards the parameres and slightly tapering from base to apex, where it curves sharply ending in an acute point. Parameres almost the length of penis guide, slightly curved towards it, widened at the base and paddle-shaped tip, with short hairs on the outer side and apical border, hairs 1/6 the length of the paramere ( Figs. 7 s-7u). Penis curved in a quarter circle in the basal half, then almost straight to the apex where it curves in the opposite direction, very short apex ending in a slightly noticeable hook towards the inner side; penis capsule with outer arm in the direction of the penis tube, twice as wide as it, subtriangular and 1 ½ times longer than wide, the inner one somewhat oblique, short, with a small curved projection towards the tube, basal margin concave, short accessory piece trapezoidal ( Figs. 7 v-7w). Female. Unknown. Variation. One of the specimens has two little noticeable yellow spots, longitudinally elongated, 1/5 as long as elytra, near the scutellar shield and at the elytral apex.

Measurements (mm): TL 6.6-7.0; PL 1.4-1.5; PW 2.9-3.2; EL 5.2-5.5; EW 4.5-4.7; GD 2.9-3.0.

Geographic distribution. Venezuela, state of Barinas.

Remarks. The genus Toxotoma Weise, 1899 , was described to include some species that had been originally described under Epilachna Chevrolat, 1837 , whose main character was having a concave clypeus and free mandibles, ending in a few short and blunt teeth, which distinguished them from the other Epilachna species, which have the mandibles partially covered by the clypeus and labrum, and have relatively sharp teeth. The appearance of these species is also very different from most Epilachna species, having a more cylindrical shape and sparser pubescence. Gordon (1975) adopted Weise’s concept when reviewing the genus, also noting that in the bifid apex of the mandibles the upper tooth was shorter than the lower one, unlike in Epilachna , and that they never had little teeth on the borders of the teeth. With this concept, Gordon (1975) included 33 species in the genus, 24 of them new; he concluded that the genera are very similar but can be distinguished by the characters mentioned above. Szawaryn et al. (2015) studied the phylogeny of the Epilachnini tribe, reaching a different conclusion for the Toxotoma and Epilachna species; they included a phylogenetic analysis of 153 species of the tribe, including all known genera, using four DNA markers and 104 morphological characters with maximum likelihood algorithms, parsimony and Bayesian inference. All analyses recognized two separate clades, reducing Epilachna to species from only eight of the 34 species groups considered by Gordon (1975) for this genus and excluding from Epilachna all non-American species; they left the previously defined species of Toxotoma , and included species from eight other groups defined by Gordon for Epilachna . These authors also indicated that it was highly probable that all the species of the indicated groups also correspond to Toxotoma . Species of the remaining 18 Epilachna groups defined by Gordon were not studied. Coinciding with Gordon (1975) the authors indicated that while Epilachna sensu novo was a genus with relatively homogeneous species, Toxotoma species formed a very heterogeneous clade with quite variable characters. The following year Tomaszewska & Szawaryn (2016) studied Epilachnini’s genera, characterizing them in detail and including a key. According to this study, Toxotoma sensu novo can be separated from Epilachna by its mandibles with incisors with smooth borders and no tubercles on their surface, the semi-circular or straight metaventral postcoxal lines, rarely descending and always complete, and the abdominal postcoxal lines sometimes reduced and barely visible. These authors transferred 12 species of Epilachna to Toxotoma , including 10 of those studied in Szawaryn et al. (2015), characterizing them in detail and including a key.

Toxotoma venezuelae n. sp. presents the characters indicated by Tomaszewska & Szawaryn (2016) for the Toxotoma , although the abdominal postcoxal lines are clearly visible and well formed, as in many species of the genus. It should be noted that E. paracuta Gordon, 1975 , from the same species group as the present species ( Epilachna angustata species group, Gordon, 1975) had already been transferred to Toxotoma by Tomaszewska & Szawaryn (2016).

Etymology. The species is named after Venezuela, where the holotype was collected.

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.