Canthidium kohlmanni Mora-Aguilar and Delgado

Mora-Aguilar, Eder F. & Delgado, Leonardo, 2019, A New Species of Canthidium Erichson (Coleoptera: Scarabaeidae: Scarabaeinae) from the Endemic Biota of Los Chimalapas, Oaxaca, Mexico, The Coleopterists Bulletin 73 (4), pp. 1067-1074 : 1068-1070

Canthidium kohlmanni Mora-Aguilar and Delgado , new species

Zoobank.org/ urn:lsid:zoobank.org:act:0A277144-6EF2-4AE6-9E14-323653931294 ( Figs. 1–7 )

Type Material. Holotype male labeled “ MEXICO: Oaxaca, San Miguel Chimalapa, Benito Juárez, El Puerto , 8-VII-2013, 16.7159° N, 94.1076° W, 1,250 m, Pinus-Quercus-Liquidambar forest, Coprotrampa, E. Mora-A. y L. Delgado cols” . Holotype is deposited in the Colección Entomológica del Instituto de Ecolog´ıa A. C., Xalapa, Mexico .

Description. Holotype male. Length 3.9 mm, width across humeri 2.7 mm. Body form moderately convex and glabrous dorsally. Head and pronotum dark green and shiny, elytra darker, striae with green reflections, legs reddish brown; clypeus and frons slightly microreticulated ( Fig. 1 ). Head: Clypeus slightly concave, apex bidentate, median emargination V-shaped, rugose-punctate anteriorly, transversally reticulated posteriorly; frons almost flat with 2 barely visible swellings, punctures confluent, sparser and shallower toward vertex; vertex slightly convex, almost impunctate on each side of midline. Eyes very narrow, with 2 facets at posterior end of genae; eyes separated by about 9–10 times maximum width of eye ( Fig. 3 ). Antennae reddish brown, sericeous. Pronotum: Surface shiny, uniformly punctate; punctures sparse, shallow, minute to small at sides, like those on vertex ( Fig. 1 ); lateral fovea semicircular and slightly marked; posterior margin lacking elongate punctures or groove. Elytra: Striae moderately impressed, interrupted by annulated punctures separated by about 2–3 diameters of 1 puncture; intervals very finely punctate, surface shiny ( Fig. 1 ). Wings: Macropterous, wings functional. Venter: Proepisternum excavate anteriorly, surface microreticulated; sternellum smooth and with a line of setiferous punctures along base; mesosternum microreticulated with minute punctures; metasternum with minute punctures denser than mesosternum ( Fig. 2 ). Abdomen: Sternites 1–6 microreticulated, with minute punctures; pygidium convex, shiny, with minute, shallow punctures ( Fig. 2 ). Legs: Protibia with 3 large teeth on external border, apical and middle teeth separated by 2 denticles, inner apical margin of protibia produced into triangular anterior projection and slightly bent downwards; apical spur simple and slightly curved inward ( Fig. 4 ); profemora microreticulated; meso- and metafemora densely punctate, punctures minute, shallow, denser apically. Aedeagus: Parameres moderately short, apices truncated to slightly rounded, inner margins slightly concave ( Figs. 5–7 ).

Etymology. We dedicate this species to Bert Kohlmann, friend and specialist of the subfamily Scarabaeinae , and author of the works on the species of Canthidium from North America and Costa Rica.

Taxonomic Remarks. This species is distinguished by the following combination of characters: body moderately convex; dorsally dark green in color, pronotum and head with a light cast green and reddish; head with rounded swellings, not tuberculate; vertex slightly punctate; eye dorsally with two facets wide at the posterior end of gena, interocular distance separated by about 9–10 times the width of an eye; antennal club reddish brown and sericeous; pronotal surface with shallow and minute punctures on disc, at sides with punctures moderate in size; basal pronotal border not margined; elytra with eight clearly punctate striae; mesosternum with minute punctures; abdominal sternites shagreened, pygidium smooth and with minute, shallow punctures; macropterous; and the shape of the parameres ( Figs. 5–7 ).

Canthidium kohlmanni is similar to Canthidium pseudoperceptibile Kohlmann and Sol´ıs (the new species was compared with paratypes of this species), but it is distinguished from C. pseudoperceptibile by the frons and vertex with denser and shallower punctures ( Fig. 3 versus Fig. 9 ), the pronotum with finer and shallower punctation ( Fig. 1 versus Fig. 8 ), the protibia with the apical and middle teeth separated by denticles ( Fig. 4 versus Fig. 10 ), and the shape of the parameres of the male genitalia ( Figs. 5–7 versus Figs. 11–12 ).

To include C. kohlmanni , we propose the following modifications in Moctezuma et al. ’s (2019) key to the species of Canthidium of North America.

13. Head and pronotum weakly punctate,

appearing smooth .............................. 13 ʹ - Head and pronotum coarsely punctate,

appearing roughened ........................... 14 13 ʹ. Punctures on pronotal disc small, moderately

deep ( Fig. 8 ); apical and middle protibial teeth

without denticles between them ( Fig. 10 ); left

paramere with projection on inner edge ( Fig.

11) ........................ C. pseudoperceptibile

Kohlmann and Sol´ıs - Punctures on pronotal disc minute, shallow

( Fig. 1 ); apical and middle protibial teeth with

denticles between them ( Fig. 4 ); parameres

without projection on inner edge ( Fig. 5 ) ...

........... C. kohlmanni Mora-Aguilar and

Delgado, new species

Distribution. Canthidium kohlmanni is only known from the type locality, in the undisturbed forests of the mountainous areas of Benito Juárez in the

4) Protibia; 5–7) Parameres, caudal, dorsal, and lateral views, respectively.

Los Chimalapas region of Oaxaca, Mexico. The locality and surrounding areas have a rugged topography with ravines and hills with mixed pine-oak forest and tropical deciduous forests at 1,250 m elevation. The distribution of C. pseudoperceptibile is allopatric with C. kohlmanni , since the former species inhabits tropical forests in the lowlands of the states of Veracruz and Chiapas in Mexico and Guatemala and Belize but on the Gulf of Mexico and Atlantic slopes.

Los Chimalapas has remained as a biologically unexplored region in Mexico, principally at elevations above 1,000 m. However, since the last decade of the last century to present, many species from this region have been described. Currently, one genus and 23 species of animals and 20 species of plants are endemic in the region (Appendix 1). Two groups stand out by the greater number of endemic species in this region, plants and beetles. Coleoptera is the most diverse group yet less studied. In Los Chimalapas, there are currently known one genus and one species of rove beetles, one species of zopherid beetle, 11 species of scarab beetles, and two species of passalid beetles that are endemic in this region (Appendix 1). Most of the species endemic species to this region are restricted to cloud and mixed forests with conifers located above 1,000 m elevation.

It is remarkable that this region conserves endemic species of large size, such as sturdy trees, e.g., Persea obscura Lorea-Hern. (Lauraceae) , or a robust beetle species, e.g., Proculus reyescastilloi Delgado and Mora-Aguilar (Passalidae) . The area of Los Chimalapas has remained as a little-disturbed region due to its mountainous and steep topography, which make accessibility difficult. Priority efforts to conserve this region must be given to maintain not only particular species, but its huge composite biodiversity of species and landscapes (Navarro- Sigüenza et al. 2008).

Figures

Figs. 1–7. Canthidium kohlmanni, holotype. 1–2) Habitus, dorsal and ventral views, respectively; 3) Head;

Figs. 8–12. Canthidium pseudoperceptibile, male paratype. 8) Habitus, dorsal view; 9) Head; 10) Protibia; 11–12) Parameres, caudal and lateral views, respectively.