Parachorius Harold, 1873

Tarasov, Sergei, 2017, A cybertaxonomic revision of the new dung beetle tribe Parachoriini (Coleoptera: Scarabaeidae: Scarabaeinae) and its phylogenetic assessment using molecular and morphological data, Zootaxa 4329 (2), pp. 101-149 : 112-114

Genus Parachorius Harold, 1873 sensu novo

Parachorius Harold, 1873: 103 (type species: Parachorius thomsoni Harold, 1873 )

Cassolus Sharp, 1875: 40 (type species: Cassolus nudus Sharp, 1875 ), new synonymy

Heteroateuchus Paulian, 1935: 115 (type species: Heteroateuchus oberthueri Paulian, 1935 ), synonym

Description. Since Parachorius is the only genus of the tribe Parachoriini, the description of the genus is the same as given for Parachoriini. In addition, I provide some relevant comparative information below.

Diagnosis. See diagnosis for Parachoriini.

Sexual dimorphism. Males are separated from females in most species by some sexually dimorphic characters. Namely, in comparison to females, males of some species may have (1) protibia with modified apical spur and/or modified first anterior tooth, (2) profemur anterior margin produced in angle, (3) angulate lateral margin and/or frontal angles of pronotum, (4) dilated metafemur posterior margin, and (5) curved and/or denticulate posterior margin of metatibia.

Morphology of endophallic sclerites. The morphology of endophallic sclerites in Parachorius varies across species. Three morphological ground plans of sclerites can be distinguished: (1) most of the endophallic sac lack sclerites, axial and SA sclerites simple, FLP absent, SRP small, LC absent ( P. javanus and P. pseudojavanus ) ( Fig. 4C ); (2) inferior portion of axial sclerite with long fork-like process (LFP), axial sclerites enlarged inferiorly with moderately short filiform process extending superiorly that reaches only FLP, inferior portion of axial sclerite with LFP, SA small ( P. globosus , P. fungorum , P. thomsoni , P. hookeri , P. maruyamai , P. newthayerae , P. pseudojavanus , P. javanus and P. schuelkei ) ( Fig. 4B ); and (3) inferior portion of axial sclerite with long fork-like process (LFP), axial sclerites enlarged inferiorly with long filiform process extending superiorly that reaches LC, inferior portion of axial sclerite with LFP, SA small ( P. longipenis , P. solodovnikovi , P. nudus , P. peninsularis , P. bolavensis , and P. fukiensis ) ( Fig. 4A ). The endophallic sclerites of three species fall outside of the provided ground plans. In P. semsanganus the structure of endophallic sclerites resembles a transitional state between ground plan 2 and 3. In P. humeralis and P. asymmetricus the FLP sclerite is absent and the endophallic sclerites are similar to those in ground plan 3. The diversity of aedeagal parameres shapes is shown in Fig. 5 .

Taxonomical note. The genus Cassolus is synonymized with Parachorius based on the result of phylogenetic analyses. Currently, Parachorius includes 19 species. A key to species and the descriptions of the new species are provided below.

Ecology. Parachorius species are quite rare in collections. In this study, I examined approximately 200 specimens, the majority of which came from recent collecting in Indochina. Their rare occurrence in collections is mainly due to their non-coprophagous feeding habits, which prevents massive collecting using dung traps. The vast majority of the specimens with known ecological data were collected in forest using flight intercept traps, carrion traps, or fruit traps.

Distribution. The genus is widespread in the Oriental and southeastern Palaearctic Regions, from Indian subcontinent in the west through Myanmar, Indochina, and southern China to Taiwan in the east. It also occurs in Sundaland, namely Malay Peninsula, Sumatra, and Java. The Philippines and Borneo lack any known species of Parachorius .

Figures

FIGURE 4. Morphological elements of Parachorius. (A – C) Endophallic sclerites; aedeagus icon in blue circle indicates position of aedeagus in relation to endophallic sclerite. (D – G) Head in dorsal view. (A, D) Parachorius longipenis. (B) Parachorius fungorum. (C, G) Parachorius pseudojavanus. (E) Parachorius gotoi. (F) Parachorius globosus.

FIGURE 5. Diversity of aedeagal parameres in Parachorius. (A) Parachorius fungorum. (B) Parachorius hookeri. (C) Parachorius schuelkei. (D) Parachorius thomsoni. (E) Parachorius globosus. (F) Parachorius newthayerae. (G) Parachorius bolavensis. (H) Parachorius fukiensis. (I) Parachorius nudus. (J) Parachorius peninsularis. (K) Parachorius pseudojavanus. (L) Parachorius javanus. (M) Parachorius solodovnikovi. (N) Parachorius longipenis. (O) Parachorius humeralis. (P) Parachorius semsanganus. (Q) Parachorius gotoi.