Onthophagus tacanensis Chamé-Vázquez & Sánchez-Hernández, 2022

Chamé-Vázquez, Eduardo Rafael & Sánchez-Hernández, Gibrán, 2022, Onthophagus tacanensis (Coleoptera: Scarabaeidae: Scarabaeinae), a new species from Chiapas, Mexico, Zootaxa 5182 (2), pp. 196-200 : 196-198

Onthophagus tacanensis Chamé-Vázquez & Sánchez-Hernández , new species

( Fig. 1 )

Type locality. Benito Juárez El Plan (15.092423°N, 92.144255ºW), Municipality of Cacahoatán , Chiapas, Mexico.

Holotype description. Holotype major male ( Fig. 1A ). Total length 7.9 mm, pronotal width 4.0 mm, elytral width 4.3 mm. Dorsal coloration is dark brown with green and coppery reflections, very marked on head and pronotum. Head shape octagonal, with anterior border and clypeogenal area angled. Anterior edge of clypeus with an upwardly directed, subtrapezoidal projection (frontal view), apex sinuate, with broad U-shaped bifurcation, directed backward towards the eyes (dorsal view). Clypeal and frontal carinae absent, clypeogenal sutures distinct. Punctures denser in the front, and sparser on the clypeus. Anterior border of head concave, with front weakly convex. Front with two cephalic horns behind the eyes, long and slender, curved inward. Anterior half of pronotum with two lateral concavities and poorly marked median frontal tubercle divided longitudinally by midline. Lateral fovea weakly marked, irregularly shaped. Punctures sparser and weakly marked on anterior half of pronotum, denser and conspicuous on posterior half. Elytral striae well marked, punctures of the same size and weakly indicated on the entire elytra, surface finely shagreened. Small setae on humeral area of last interstriae. Pygidium with irregular punctures, surface moderately shagreened, with scattered setae towards the sides. Prothoracic legs with outer edge of tibia with four teeth and a tuft of long setae at apex. Apex of parameres with sharp, well-developed apical tooth ( Fig. 1C ). Endophallite as indicated in Fig. 1D .

Female allotype. Similar to male except in the following characteristics ( Fig 1B ): head sub-pentagonal, with anterior edge of the clypeus bidentate; clypeal carina distinct; clypeus, front, and gena rugose with distinct punctures; frontal horns almost half the size of males, semi-conical, and directed upwards; anterior half of pronotum with two small, conical protuberances; pronotum surface with evenly distributed punctures.

Variation. Total length 5.5–8.6 mm, pronotal width 3.1–4.3 mm, elytral width 3.1–4.5 mm. Coloration varies from dark brown to almost black, without green highlights. In underdeveloped males, clypeal projection small and not bifurcate at apex, apex may be straight. In weakly developed females, pronotal horns small and pronotal protuberances may be almost absent.

Type material. HOLOTYPE (male): MEXICO. Chiapas: Cacahoatán, Benito Juárez El Plan, carrion trap, 18 April 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( ECFS: ECO-TAP-E-21472) . ALLOTYPE (female): MEXICO. Chiapas: Cacahoatán, Benito Juárez El Plan, carrion trap, 18 April 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( ECFS: ECO-TAP-E-21328) . PARATYPES (10 males, 10 females): MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 7 March 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( ECFS: ECO-TAP-E-21309) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 6 April 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( ECFS: ECO-TAP-E-21467, ECO-TAP-E-21470) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 18 April 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( CNIN: ECO-TAP-E-21437, ECO-TAP-E-21371, ECO-TAP-E-21372, ECO-TAP-E-21449) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 3 May 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( ECFS: ECO-TAP-E-21385) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 22 May 2010, 15.092423°N, 92.144255°W, cornfield, 1470 m, R. Cancino ( CMN: ECO-TAP-E-21361, ECO-TAP-E-21353, ECO-TAP-E-21466) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 14 August 2010, 15.097791°N, 92.139211°W, montane mesophyll forest, 1720 m, R. Cancino ( ECFS: ECO-TAP-E-21355, ECO-TAP-E-21384, ECO-TAP-E-21429, ECO-TAP-E-21463) ; MEXICO. Chiapas: Cacahoatán, Benito Juárez El Plan, carrion trap, 11 September 2010, 15.097791°N, 92.139211°W, montane mesophyll forest, 1720 m, R. Cancino ( ECFS: ECO-TAP-E-21446); MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 22 May 2010, 15.085405°N, 92.148736°W, shaded coffee plantation, 1370 m, R. Cancino ( ECFS: ECO-TAP-E-21314, ECO-TAP-E-21364) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 11 September 2010, 15.085405°N, 92.148736°W, shaded coffee plantation, 1370 m, R. Cancino ( ECFS: ECO-TAP-E-21410) ; MEXICO. Chiapas: Cacahoatán , Benito Juárez El Plan, carrion trap, 23 October 2010, 15.085405°N, 92.148736°W, shaded coffee plantation, 1370 m, R. Cancino ( ECFS: ECO-TAP-E-21380) . Holotype, allotype and 13 paratypes are deposited in ECFS , four paratypes deposited in CNIN and three paratypes in CMN .

Distribution and ecology. The species was collected with NTP-80 carrion traps, baited with squid and fish in mesophyll mountain forest disturbed areas between 1370–1720 m. So far, this species is only known from area around the type locality on the slopes of the Tacaná Volcano, Chiapas, Mexico ( Fig. 2 ). This species was cited as “ Onthophagus sp1 ” in Cancino-López et al. (2014), with an important presence in rainfed maize and bean crops (with a rotation every three years), being less representative inside shade coffee plantations and mesophyll mountain forests. Onthophagus anthracinus Harold, 1963 , O. cyanellus Bates, 1887 , and O. incensus Say, 1835 have been collected in this same locality. This new species appears to follow the Mesoamerican montane distribution pattern (sensu Halffter & Morrone 2017) and might be found in other areas of the mountain chain between Chiapas ( Mexico) and Guatemala.

Etymology. This species is named after the locality it was collected, which is the Tacaná Volcano, Chiapas, Mexico.

Diagnosis. This species is similar to O. andersoni Howden & Gill, 1987 ; both have the apex of the clypeal projection sinuate (notched), but the bifurcation does not reach the gena, similar to the clypeal projection described for O. belorhinus Bates, 1887 . Pronotal concavities are marked and not present in O. andersoni and O. belorhinus , although the pronotal protuberance is very similar between O. andersoni and O. tacanensis . Likewise, O. andersoni is larger (7.0–10.0 mm) than O. tacanensis (5.5–8.6 mm). Three of the five species that make up the O. belorhinus species complex have a Ushaped horn bifurcation ( O. belorhinus , O. andersoni , and O. tacanensis ).

Figures

FIGURE 1. Onthophagus tacanensis new species. A, male dorsal habitus; B, female dorsal habitus; C, aedeagus; D, endophallite.

FIGURE 2. Distribution of the Onthophagus belorhinus species complex.