Aegognathus leuthneri Van de Poll, 1886

Cáceres, Juan Sebastián D. & Grossi, Paschoal Coelho, 2023, Taxonomic revision of Aegognathus Leuthner, 1883 (Coleoptera: Lucanidae), Journal of Natural History 57 (9 - 12), pp. 557-595 : 571-573

Aegognathus leuthneri Van de Poll, 1886

( Figure 2d–f : 1 major J; 1 minor J; 1 ♀)

Aegognathus leuthneri Van de Poll, 1886: 153 (original combination and description)

Examined material

Holotype male labelled ′ Colombia ̍ ( MNHN) . Additional material: Ecuador, La Bonita, Sucumbios, vi . 2000, 2 500 m – 1J ( CERPE); Equador, (Succ), La Bonita, xi .2000, Alt: 2100 m – 3J ( EPGC) .; Ecuador, La Bonita, Sucumbios, vi . 2000, 2500 m – 1♀ ( CERPE) .; Equador, (Succ), La Bonita, xi .2000, Alt: 2100 m – 1♀ ( EPGC) .; Ecuador, Napo, Cosanga xi .2001 – 1♀ ( EPCG) .

Diagnosis

Males dorsally black with red to dark red spots, ventrally mainly black with some dark red regions at head and coxae. Head glabrous, surface shagreened, mandibles with rounded to somewhat acuminate apex. Pronotal surface glabrous except for lateral margins. Elytra with coarse, densely distributed punctures with erect dendritic setae along disc, laterally with smooth decumbent setae. Abdominal ventrites laterally carinate, ventrite II laterally wrinkled. Dorsal cross bar of aedeagus with wider posterior lobes. Females same as males except for presenting darker tones along body, stronger punctation dorsally, punctures coarse, contiguous to dense. Heads and mandibles reduced with acuminate apex, asymmetrical. Elytra with weak longitudinal costae.

Description – male

Size: Total length. 12.1–22 mm. Total width. 2.6–4.7 mm. Colour: Body with black and red regions. Head mainly black with a small dark red region at the anterior portion; mandibles black. Pronotum with two black spots, lateral regions and disc dark red. Elytra mainly red, especially along lateral margins with three longitudinal black areas close to the suture, alternating with thin red regions. In ventral view black, except for some small dark red regions over the mentum and coxae. Head: Shape transverse; surface glabrous, shagreened; temporal process weak, practically absent in small males; mandibles as long as head and first half of pronotum, bend inwards with rounded to slightly acuminate apex, in the middle with an upwardly directed tooth, rounded apically and absent in small males. Pronotum: Surface shagreened, glabrous except laterally, with a longitudinal groove along disc; anterior angles rounded; posterior angles acuminate. Elytra: Surface uniformly punctured, punctures dense, coarse, with erect yellowish dendritic setae along the disc, becoming longer along lateral and posterior margins, present as smooth setae over the margins. Epipleural punctures large to somewhat coarse, dense, with small yellowish appressed setae. Legs: Protibiae externally serrate with variable number of external teeth, frequently with three strong distal teeth, one at apex internally and one apical spur. Mesotibiae with four apical teeth, and one median tooth. Metatibiae with a small median external tooth, apex like that of mesotibiae. Venter: Mentum trapezoidal with a transverse groove, punctate with small yellowish appressed setae. Gena carinate along the posterior region, punctures moderate and sparse. Prosternum with two continuous band of yellowish setae along anterior and posterior margins; surface strongly punctate, with small yellowish appressed setae. Mesoventrite punctate mainly over the median region and sides, with yellowish appressed setae. Metaventrite almost uniformly punctate; discrimen a longitudinal groove over the last third of metaventrite. Abdominal ventrites with a weak longitudinal carina along lateral margins, uniformly punctate, punctures large and dense; abdominal ventrite II showing two or more transverse depressions at sides. Genitalia ( Figure 7b ): Aedeagus symmetrical, subtriangular and somewhat truncate. Basal piece subtriangular; disc with a translucent region and concave sides; 2.0 times longer than parameres. Median lobe almost cylindrical; dorsally with ′X̍- shaped cross bar, with wider posterior lobes. Parameres with somewhat concave sides and truncate to slightly rounded ends, internal and posterior margins setose. Internal sac about as long as the basal piece, with a paired longitudinal strap-like sclerites that end at the beginning of the apical third; apex darker and subconical, ending in the gonopore.

Description – female

Size: Total length. 12.4–13.6 mm. Total width. 4.3–4.5 mm. Colour: In dorsal view mainly black, with several dark red spots distributed over the anterior region of head, pronotum, and elytra, also with one to a few longitudinal red lines along the suture. In ventral view black. Head: Smaller than male heads; surface highly punctate even along mandibles, punctures coarse, contiguous to dense, with small erect setae, mandibles asymmetrical, reduced compared with males, being only as long as the first half of head, with a somewhat rectangular laminar tooth, larger at the left mandible and acuminate apex. Pronotum: Surface strongly punctate, punctures coarse, mainly contiguous, with erect to curved small yellowish setae; anterior angles acute; anterior portion somewhat convergent. Elytra: Surface highly punctate, punctures coarse and dense, with yellowish curved setae along lateral margins, and dendritic along disc; irregular longitudinal costae present over disc. Legs: As in males. Venter: As in males except for presenting large and dense punctures and a more distinct continuous discrimen; with longer setae along abdominal ventrites. Genitalia ( Figure 7c ): Styli symmetrical, transverse, elongate. Distal coxite subquadrate with conspicuous simple setae. Proximal coxite convex, medially setose, finely sclerotised.

Distribution

Northern Ecuador, Northern Central Cordillera, Colombia?. Paramo province ( Morrone et al. 2022).

Remarks

Aegognathus leuthneri is the only Aegognathus species from Ecuador, and was originally described from Colombia by Van De Poll (1886). Unfortunately the original description of the species lacks precise location data but, given the proximity of the Ecuadorian Napo province to Colombia, we expect that the current distributional range could be extended to south-western Colombia, along the eastern slopes of Colombian ′Cordilleras̍. Aegognathus leuthneri bears a strong resemblance to A. damasoi (originally considered a subspecies), but besides the differences in distribution, the two species can be separated by the highly conspicuous yellowish setae shown by males and females of A. damasoi along pronotum and elytra.

Figures

Figure 2. Dorsal habitus of Leptinopterus caledoniaensis (Grossi, Racca-Filho and Vaz-de-Mello 2003): (a) male and (b) female from CERPE; (c) male holotype Aegognathus waterhousei Leuthner, 1883 from NHM. Aegognathus leuthneri Van De Poll, 1886 from CERPE: (d) major male, (e) minor male and (f) female. Scale bars: 5 mm.

Figure 7. Ventral view of A. waterhousei: (a) male aedeagus. Aegognathus leuthneri: (b) male aedeagus and (c) female genitalia. Aegognathus soulai: (d) male aedeagus and (e) female genitalia. Aegognathus similis: (f) male genitalia and (g) female genitalia. Scale bars: 1 mm.