Diplotaxis complanatis, Delgado & Toledo-Hernández, 2020

Delgado, Leonardo & Toledo-Hernandez, Victor Hugo, 2020, Three new species of Diplotaxis Kirby from Guatemala and Mexico (Coleoptera, Scarabaeidae, Melolonthinae), with a key to the species of the trapezifera group, ZooKeys 993, pp. 35-46 : 35

Diplotaxis complanatis sp. nov. Figs 11-16

Material examined.

Holotype male, “México: Oaxaca, km 21 Carr. Yolotepec-Juquila, VIII-1993, Alt. 1,900 m, bosque mesófilo, luz, L. Delgado col." (IEXA). Paratype female, same data as holotype (IEXA). Three male and one female paratypes, same data except: "31-VII-1-VIII-1991, luz u.v., J. L. Navarrete, G. Quiroz y L. Delgado cols." (CNIN, SMC, LLDC).

Diagnosis.

This tiny species is recognized by the following combination of characters: body dorsoventrally flattened, clypeal surface with a few and minute setae, pronotum and elytra glabrous or with scarcely visible setae (shorter than diameter of one puncture), and dorsum shiny but without a metallic cast.

Description.

Holotype. Male (Figs 11-15 ). Length 6.58 mm; width 3.26 mm. Body elongate and dorsoventrally flattened. Clypeus reddish, frons and vertex black, pronotum reddish, elytra reddish-brown; dorsum shiny, without metallic cast.

Head. Clypeus trapezoidal in shape, length equals 0.66 that of frons, apex broadly emarginated with anterior angles rounded, and sides indented in front of eyes; surface concave, coarsely rugose, with scarce, minute setae near external margins; frontoclypeal suture barely marked; frons slightly concave, gradually declivous to clypeus, with large and dense punctures; transverse eye diameter 0.34 interocular width; antennae 10-segmented; labrum with anterior half slightly convex and posterior half concave, length equals 0.50 of that of reflexed underside of clypeus, surface with small, sparse punctures; mandibles moderately robust in frontal view; mentum convex, with anterior declivity marked by an arcuate, setiferous ridge; last article of maxillary palps not impressed dorsally.

Pronotum. Hexagonal in shape, anterior angles right, lateral margins obtusely angled near middle, posterior angles obtuse; surface slightly convex, with a shallow fovea on each side; punctation coarse on disc, confluent along sides; basal margin beaded, with a row of small punctures.

Scutellum. With sparse, medium-sized punctures. Elytra. 1.7 times longer than width, broad intervals with coarse punctures, many of which confluent, narrow intervals slightly raised; elytral punctures with setae minute, barely visible.

Abdomen. Without lateral carina; propygidium without groove anterior to pygidium; ventrites 2-5 subequal in length, surface with small setae; pygidium 1.8 times wider than long, slightly convex in basal 3/4, apical fourth flat; surface with coarse, deep punctures, with sparse setae on apical third.

Legs. Protibiae tridentate, basal tooth situated nearly at middle and removed from apical teeth; claws bent and subapically cleft; tarsi longer than respective tibiae; apex of protarsomere 2 with a small denticle (Fig. 13 ), mesotarsomere 1 longer than 2; metacoxal plates margined and rounded laterally; metafemora straight and slender; metatibial spurs long and acute; metatarsomere 1 shorter than 2, and almost as long as longest spur.

Genitalia. Basal piece almost as long as parameres, parameres joined along inner margin in basal third, almost parallel, and with apices rounded and slightly widened (Figs 14-15 ).

Variation.

Three male and two female paratypes. Males: length 6.5-7.2 mm, width 3.1-3.3 mm. Females: length 7.2-7.6 mm, width 3.6-3.9. In both sexes, the color and punctation varies slightly. Females differ from males in having frons more convex; abdomen slightly more convex; tibiae and femora broader and robust, protarsomere 2 without a denticle; inner metatibial spur longer than metatarsomere 1.

Etymology.

The name of this species is derived from the Latin complanatae, meaning flat, in relation to the dorsoventrally flattened body.

Distribution.

This species is known only from the type locality, which is situated in the Sierra Madre del Sur, in the state of Oaxaca, Mexico (16°14'33.4"N, 97°15'01"W) (Fig. 17 ). The locality is on the slope facing southward to the coast, at 1900 m altitude, in a transition between pine-oak and cloud forests. The specimens were attracted to ultraviolet light traps.

Taxonomic remarks.

This small species has a dimorphic character which is so far unique for this genus: the presence in the males of a minute denticle on the apex of protarsomere 2 (Fig. 13 ). The clypeus with minute setae and the rest of the dorsum glabrous (or nearly so) relate this species with the trapezifera group, however, D. complanatis sp. nov. exhibits a dorsoventrally flattened body. This species can be distinguished from D. chiapasensis sp. nov. and D. xalapensis by its shiny body, but without a metallic green cast (Figs 11 , 16 ).

Figures

Figure 17. Distribution of Diplotaxis species. Diplotaxis balam sp. nov. (black circle), D. chiapasensis sp. nov. (black triangle), D. complanatis sp. nov. (white circle), D. xalapensis Delgado and Capistran (white triangle).

Figures 11 - 16. Diplotaxis complanatis sp. nov. 11 male habitus, dorsal view 1 2 male habitus, lateral view 1 3 male protarsomeres 14 male genitalia, frontal view 15 male genitalia, lateral view 16 female habitus. Scale bars: 1 mm (11, 12, 16); 0.5 mm (13 - 15).