Eumorphusmarginatus group in Sulawesi, Indonesia (Coleoptera, Endomychidae)

Abstract The species of the Eumorphusmarginatus group from Sulawesi are revised. Two previously known species, E.costatus and E.wegneri, are redescribed, and a new species, Eumorphusmirabilissp. n., is described. A key for identification of these species is provided.


Introduction
Eumorphus Weber, 1801 is the largest genus in the subfamily Lycoperdininae of the family Endomychidae. It includes 77 species/subspecies (Shockley et al. 2009, Chang andRen 2017). Strohecker (1968) classified species of this genus into seven species groups (three species were undetermined). Of these, the Eumorphus marginatus group (sensu Strohecker 1968) includes well-known beetles having a unique body shape like tortoise beetles (Chrysomelidae, Hispinae). Approximately 30 species (including subspecies) are known in this species group (Strohecker 1968), but the knowledge about most species is limited and reexamination is needed. For example, Eumorphus marginatus Fabricius, 1801, the largest and most well-known species (Arrow 1925), has been recorded from Borneo, Java, Sumatra, Papua New Guinea, the Philippines, Myanmar, and Lanyu (Kano 1928). This species seems to be widely distributed, but its distribution and taxonomic status needs revision. In addition, the endophallic structure of the subfamily Lycoperdininae is diverse in shape, size, and construction (e.g., Tomaszewska 2005), but this has been scarcely studied so far.
In the present paper, we describe a remarkable new species from Sulawesi, Indonesia, and provide redescriptions of two previously known species of E. marginatus group from this island. The male genitalia of these species including endophallic structure are also described.

Materials and methods
The material examined in this paper is lodged in Ehime University Museum, Matsuyama, Japan (EUMJ) and National Museum of Nature & Science, Tsukuba, Japan (NSMT). General observations, dissections, and microstructures of the dissected parts were made under a Leica MZ95. After observation, the dissected parts were mounted on the same card with the specimen. Photographs were taken under the Leica MZ95.
Morphological abbreviations used in this study are as follows: EL elytral length from anterior margin to elytral apex, along suture including scutellum; EW maximum elytral width; PLM pronotal length in median line; PLS pronotal length from anterior angle to posterior margin; PWA pronotal width in anterior angles; PWP pronotal width in posterior angles; TL total length (PLM + EL).
The average measurement is given in parentheses after the range. Technical terms follow Tomaszewska (2005) and Sogoh and Yoshitomi (2017). The orientations of the aedeagus in the abdomen are as follows: the view with the apical and subapical branches situated on the right side is ventral (Fig. 6A, E, I), upside is right lateral (Fig. 6B, F, J), and left side is dorsal (Fig. 6C, G, K). The label data of the specimen examined is cited verbatim in the original spelling and given in quotation marks ("…").
Diagnosis. Eumorphus is most similar to Platindalmus and Gerstaeckerus, but is distinguished from these by the following combination of characters: 1) lateral margin of pronotum with a tendency to form irregularly broken lines, inconsistent and often asymmetrical; 2) apex of mandibles narrowly chisel-shaped; 3) basal margin of elytra simple; 4) intercoxal process of mesoventrite subparallel-sided; 5) male femora lacking fringes of long hairs on inner edges (after Tomaszewska 2005).
The Eumorphus marginatus group (sensu Strohecker 1968) is characterized as follows: large body size; elytra with lateral flattened margins wide, elevated dorsally in mesal part in male; male fore tibiae with sexual dimorphism.
Biological notes. Eumorphus marginatus Fabricius, 1801 was collected from Polyporus sp., and living individuals apparently have a strong unpleasant smell, much like that of the seeds of Parkia speciosa (after Arrow 1925). The larva of Eumorphus quadriguttatus (Illiger) was described by Bugnion (1909) and Hayashi (1986), and Tomaszewska (2005) provided a description of the larva of a Eumorphus sp. with figures. Diagnosis. This species is similar to Eumorphus marginatus Fabricius, 1801 but differs from the latter in the following characteristics: elytral spots smaller, each distant from suture by its own diameter; in E. marginatus elytral spots larger and distant from suture by 1/2 of its own diameter).
Aedeagus (Fig. 6A-D) 5.4 mm long; median lobe stout, expanded ventrally in median part; apical branch short, obtuse and bisinuate at apex; subapical branch long, evenly curved apically; tegmen not movable, with short tegminal strut; endophallus consisting of bifid long right membranous lobe and left membranous lobe, with rather sclerotized spinous plate at base of left lobe.
Female. Not available for examination.
Distribution. Indonesia (Sulawesi: south and west). Diagnosis. This species can be easily separated from all other Eumorphus species in having cordiform elytra possessing one pair of spots and the pronotum laterally serrated.