Chrysina chimalapensis Mora-Aguilar, Curoe, Delgado

Mora-Aguilar, Eder F., Curoe, Daniel, Delgado, Leonardo & Ramírez-Ponce, Andrés, 2018, A new Mexican species of Chrysina Kirby (Coleoptera: Scarabaeidae: Rutelinae), with nomenclatural changes, new records, and a key to the C. quiche species group, Zootaxa 4461 (2), pp. 196-204 : 197-200

Chrysina chimalapensis Mora-Aguilar, Curoe, Delgado , & Ramírez-Ponce, new species

Figs. 1–10 .

Type material. Holotype male labeled: “ MEXICO : Oaxaca, San Miguel Chimalapa, San Antonio, Camino al Retén (a la Torre), 24-VII-2017, 16.6637° N, - 94.2335 ° W, 1760m, Luz mercurial, 1am, BMM, D. Curoe, A. Ramirez-P, E. Mora-A. cols”. One female paratype with same data as holotype except: “ 26-VII-2017, 1 800, Luz aditivos metálicos, 4 am” . Holotype and paratype are deposited in IEXA.

Description. Holotype male ( Figs 1–7 ). Length 26.8 mm; width at elytral humeri 12.6 mm; maximum width (middle of elytra) 14.2 mm. Color: Dorsum mostly shiny green; external margin and frontal surface of clypeus, labrum, and mandibles yellowish golden; ocular canthi and periocular areas yellowish orange to pink; antennomeres reddish brown with scape yellowish brown dorsally, antennomere 2 with a greenish patch dorsally, club slightly lighter; pronotal disc yellowish green, pronotal lateral margins yellowish pink, anterior and posterior margins yellowish medially; scutellum yellowish green on base, with apical margins edged with yellowish orange and narrow golden band; elytra with epipleuron and external margin yellowish golden, humeral and apical umbones green, elytral suture and striae yellow; propygidium iridescent yellowish green; pygidium green with margins iridescent yellowish golden. Venter yellowish green with golden reflections; sternites with apical margins iridescent yellowish pink; mesometasternal projection iridescent golden at apex. Legs with coxae yellowish green; trochanters iridescent yellowish green; femorae, tibiae dorsally olive green with orange reflections; tarsi golden olive green, tarsomeres 5 with orange reflections; claws reddish brown with green reflections dorsally. Surface entirely microreticulate. Head: Clypeus subparabolic; lateral margins almost straight and convergent, apex rounded and slightly reflexed at margin; disc slightly concave; surface densely rugopunctate; punctures denser and confluent near apex. Frons slightly convex with sides straight in lateral view; disc surface more sparsely punctate than on clypeal disc. Interocular distance 1.5 times greater than antennal club length. Antennal club longer than previous six antennomeres; antennomere 2 swollen and subcylindrical ( Fig. 4 ). Labrum slightly concave at middle, and slightly produced and rounded at middle of posterior margin. Mentum subquadrate; apical margin broadly emarginate with two rounded denticles at middle; distally with long and narrow transverse, rugose depression; basally with longitudinal, foveate depression; surface otherwise setigerously punctate; punctures sparse, large, and small, larger on sides; setae long, pale. Pronotum: Punctures on disc finer and sparser than on head becoming denser laterally; pronotal margins completely beaded except behind frons and anterior to scutellum; pronotal width at base equal to 2.3 times interocular distance. Elytra: Punctate-striate; striae shallow; punctures in striae and intervals small in size, separated by 2–4 puncture diameters; intervals moderately convex; second, fourth, and sixth interstriae almost impunctate on basal two thirds. Epipleuron extending to level of apical margin of the second abdominal sternite. Elytron 3.1 times as long as pronotum; lateral margin almost completely beaded; effaced at apex. Pygidium: Surface convex, strongly so in apical third; disc surface rugopunctate, denser on base and sides; base and sides reticulate; apex impunctate; apical margin and sides with scattered setose punctures; setae short and pale. Venter: Mesometasternal projection acute and slightly directed away from body (lateral view), apex rounded (ventral view), almost reaching base of prosternal projection ( Figs. 2–3 ). Mesoepimeral disc reticulate. Mesosternum and metasternum, metaepisternum, and metaepimeron densely, setigerously punctate; setae dense, long and pale. Apical ventrite concave, with a shallow, transversal depression. Legs: Profemora and mesofemora with scattered long, pale setae. Mesotibia with one transversal carina; metatibia with two carinae, basal carina weak; tibial carinae bordered with spiniform setae. Protibia distinctly tridentate, dorsal and ventral surfaces rugopunctate; protarsus and spur articulate in apical fifth. Protarsomeres 3–5 longitudinally striated on their inner side. Genitalia: Parameres short, nearly symmetrical, deeply and narrowly notched; each lateral external margin with three subtriangular denticles; color reddish brown with coppery cast; length of genital capsule 8.6 mm ( Figs. 5–7 ).

Paratype. Female ( Figs. 8–10 ). Length 28.4 mm; width at elytral humeral umbones 12.1 mm; maximum width (middle of elytra) 14.2 mm. Similar to male except in the following respects: Head darker, clypeus longer and subtriangular, apex in frontal view slightly reflexed dorsally, clypeus less convex; interocular distance 2.0 times wider than antennal club length; antennal club subequal in length to previous six antennomeres. Pronotal width at base equal to 2.0 times interocular distance. Elytra 3.0 times as long as pronotum; epipleuron expanded, reaching level of apical margin of second sternite. Last sternite with a narrow transversal depression in medial third, concave near apex. Pygidium with surface more strong declivous laterally; punctate at disc, and sides rugopunctate to reticulated. Tibiae with punctation denser and coarser. Protibia and spur wider and shorter, protarsus and spur articulated in apical fourth. Protarsus slender with only protarsomeres 4 and 5 longitudinally striated. Mesotibia and metatibia wider and shorter. Metatibial spurs wider. Genital plates inverted anchor-like in shape, with setae scattered, short, and pale; each plate with a long and slender posteriorly directed spine, length of plates 3.4 mm ( Fig. 10 ).

Diagnosis. Chrysina chimalapensis is recognized from the remaining species of the C. quiche species group by the following combination of characters: antennomeres 2 subcylindrical without protrusion, basal pronotal bead effaced medially, males with parameres with three denticles on both external margins, and females with sides of plates convergent apically and with anterolateral angles widely rounded.

Remarks. Chrysina chimalapensis is placed in the C. quiche species group (sensu Hawks 2001), which also comprises C. quiche (Morón) , C. tecunumani (Cano & Morón) , and C. benesi Pokorný & Curoe.

The C. quiche species group of Chrysina is morphologically homogeneous and can be distinguished from other Chrysina groups by the following combination of characters: medium size (24–28 mm); habitus shiny green except green-gold to pink external margin of clypeus, periocular areas, pronotal margins, apical margins of scutellum, elytral sutural margins and mesometasternal projection; lateral margin and apical calla of elytra green; elytra with shallow but distinct striae and narrow epipleura, reaching level of second abdominal sternite; mesometasternal projection short with apex rounded (ventral view); male genitalia with parameres short, nearly symmetrical and almost straight in lateral view, and with ventral plates of the phallobase widely separated, slender, apically acute and bent or curved toward one another; female genitalia with inferior plates inverted anchor-shaped, with a basolateral denticle on each side.

Monzón (2006) also included C. schusteri (Monzón, Cano, & Bailey) within the C. quiche species group. Although externally similar to these species, C. schusteri differs from them by its male genitalia with parameres long (more than half the length of basal piece) and slightly curved at the apical half. Also, the ventral plates are adjacent to each other and rounded apically. The female genitalia have the inferior plates T-shaped and with basolateral lobes. Based on these differences, we prefer to exclude C. schusteri from the C. quiche species group.

The four species of the C. quiche species group are externally nearly indistinguishable; examination of genitalia is necessary for determination ( Pokorný & Curoe 2012).

Etymology. The specific epithet is derived from Chimalapas, the region of the state of Oaxaca where this species was collected, combined with the Latin suffix –ensis, meaning belonging to.

Distribution. Chrysina chimalapensis is currently known to occur only in the cloud forest of El Retén, in the Chimalapas region located at the southeast end of the state of Oaxaca State ( Fig. 17 ). The forests at the type locality and neighboring areas (1,450–1,800 m) present a high degree of conservation. The canopy in the cloud forest of Chimalapas is composed of trees of the genera Alchornea (Euphorbiaceae) , Clethra (Clethraceae) , Coccolba ( Polygonaceae ), Ficus (Moraceae) , Ocotea (Lauraceae) , Persea (Lauraceae) , and Quercus (Fagaceae) (Lorea- Hernández 2005).

The species of the C. quiche species group are restricted to the cloud forests located above 1,600 m in southern Mexico (Oaxaca and Chiapas), and Guatemala, in the Chiapas Highlands biogeographic province (sensu Morrone 2014). All species, except C. quiche , show isolated distributions in different geographical areas ( Fig. 17 ), which fits the Nuclear Central America areas of endemism of proposed by Schuster et al. (2000). The distribution area of C. chimalapensis is isolated from the remaining portion of the Sierra Madre de Chiapas in Mexico by areas below 1,000 m elevation. Chrysina benesi is known from one locality in the state of Chiapas, located at the southeast of the Sierra Madre de Chiapas, and, in Guatemala, in the north of the Sierra Los Cuchumatanes. Chrysina tecunumani is only known from the Sierra de Chama and Sierra de Las Minas in the central region of Guatemala. Chrysina quiche shows the widest distribution, occurring in the Sierra Madre de Chiapas in Mexico, and, in Guatemala, in the Cordillera Volcánica Occidental, the Sierra de Chama, and the Sierra de Las Minas (J. Monzón, Guatemala City, Guatemala, personal communication). The previous record from the eastern region of the Sierra de los Cuchumatanes for C. quiche ( Monzón 2006) is erroneous (J. Monzón, personal communication).

Natural history. Chrysina chimalapensis is attracted at night to mercury vapor and metal halide light and is sympatric with C. triumphalis Morón and C. quetzalcoatli (Morón) , with the new species being the least abundant in this six collecting events at this locality.

Figures

FIGURE 17. Geographical distribution of the Chrysina quiche species group. Chrysina benesi (black triangle), C. chimalapensis (grey triangle), C. quiche (black squares), C. tecunumani (open squares). Elevation limits of 1,200, 1,800, and 2,400 m, darker gray lines indicate lower elevation.

FIGURES 1–10. Morphological characters of Chrysina chimalapensis. 1, Habitus of male; 2, lateral view of male; 3, ventral view of male; 4, head of male; 5, distal view of parameres; 6, ventral view of parameres; 7, lateral view of parameres; 8, habitus of female; 9, head of female; 10, genital plates.