Atholus coelestis (Marseul, 1857)

dela Cruz, Ian Niel & Ohara, Masahiro, 2023, Revision of the genus Atholus Thomson, 1859 (Coleoptera, Histeridae, Histerinae) from the Philippines with additional records, ZooKeys 1158, pp. 1-26 : 1

Atholus coelestis (Marseul, 1857)

Figs 2 , 9-14 , 38-40

Hister coelestis Marseul, 1857: 416, tome, 10, fig. 59 [China].

Hister (Atholus) coelestis : Bickhardt 1910: 53 [catalogued]; 1917: 193 [catalogued]; Desbordes 1919: 399 [Tonkin, Annam, Cochinchine]; 1921: 10 [India]; Kamiya and Takagi 1938: 31 [listed].

Atholus coelestis : Lewis 1906: 402; 1915: 55 [Formosa=Taiwan]; Mazur 1984: 212; 1997: 129; 2011: 104 [catalogued]; Mazur et al. 2015: 1454 [Philippines]; Ôhara, 1992: 173-176; 1994: 137; 1999: 110 [Nansei Islands]; 1999b: 31-32 [Taiwan].

Atholus (Euatholus) coelestis : Hisamatsu and Kusui 1984: 17 [noted, key].

Atholus (Euatholus) coelestes [sic]: Hisamatsu 1985: 228, pl. 41, f. 61 [noted, key, image].

Hister femoralis Motschulsky, 1863: 449, synonymized by Lewis 1885: 465.

Specimens examined.

13 ♂♂, 2 ♀♀ and 4 specimens of undetermined sex. Luzon Island , Isabela, Angadanan, Pissay , 1 ♂, 16.44207°N, 121.46277°E 60 m a.s.l., 2019-VII-20 [IS-19-IDC-001], I.N. DELA CRUZ leg.; Pangasinan, Asingan, Bantog, 1 ♂, 15.59384°N, 120.41151°E 50 m a.s.l., 2019-VII-22 [PG-19-IDC-001], I.N. DELA CRUZ leg.; Batangas, Calatagan, Balitoc, 1 ♀, 13.51417°N, 120.38138°E 10 m a.s.l., 2019-VI-26 [BG-19-IDC-001], I.N. DELA CRUZ leg. Mindoro Island, Oriental Mindoro, Mt. Halcon , 1 ex., 2005-IV. Panay Island , Capiz, Dumarao, Bugsuan , 3 ♂♂, 11.14422°N, 122.44405°E 76 m a.s.l., 2019-VIII-03 [CP-19-IDC-001], I.N. DELA CRUZ leg.; Antique, Patnongon, Igbobon, 1 ♂, 1 ex. [IC-21-20], 10.55434°N, 121.59592°E - 10 m a.s.l., 2019-VIII-02 [AQ-19-IDC-001], I.N. DELA CRUZ leg.; Iloilo, Calinog, Simsiman, 1 ♂, 11.07008°N, 122.32289°E 70 m a.s.l., 2019-VIII-01 [II-19-IDC-001], I.N. DELA CRUZ leg. Guimaras Island, Guimaras, Jordan, Alaguisoc, 1 ♂, 10.37576°N, 122.36379°E 153 m a.s.l., 2019-VII-30 [GU-19-IDC-001], I.N. DELA CRUZ leg. Negros Island, Negros Occidental, La Carlota, La Granja, 1 ♂, 10.23566°N, 122.59334°E 90 m a.s.l., 2019-VII-29 [NC-19-IDC-002], I.N. DELA CRUZ leg.; Negros Occidental, Mt. Canlaon , 1 ex., 1988-IV-11-30, D. MOHGAN leg.; Negros Oriental, Tanjay, Azagra, 1 ex., 09.29363°N, 122.08473°E 0 m a.s.l., 2019-VII-31 [NR-19-IDC-001], I.N. DELA CRUZ leg. Cebu Island, Cebu, Tuburan, Poblacion, 1 ♂, 10.43204°N, 123.49155°E 15 m a.s.l., 2019-VII-27 [CE-19-IDC-001], I.N. DELA CRUZ leg. Mactan Island, Buyong Maribago, Lapu-lapu City, 1 ex., 1996-IV-3, S. SHIMANO leg. Mindanao Island , Agusan del Norte, Butuan, Tiniwisan, 1 ♂, 1 ♀ [IC-21-11], 08.57694°N, 125.35521°E 20 m a.s.l., 2021-V-01 [AN-21-IDC-001], I.N. DELA CRUZ leg.; Taligaman, 2 ♂♂, 08.56894°N, 125.38534°E 60 m a.s.l., 2021-VI-14 [AN-21-IDC-003], I.N. DELA CRUZ leg.

Diagnosis.

Atholus coelestis (Marseul, 1857) is best characterized by its third dorsal elytral stria extending inwardly towards the apical end of the fourth and fifth striae. The slight emargination on the anterior margin of the mesoventrite is also a distinct character of this species. The number of denticles of the protibia (Figs 13 , 14 ), is 11 on the outer margin, one one the inner apical angle, and eight on the outer sublateral margin. The protibial teeth are slightly prominent only on the outer apical angle, topped with three denticles. The number of denticles on the outer margin may range from 11-13 denticles. The shape of the gonocoxite of A. coelestis (Marseul, 1857) is slenderer, becoming narrower towards the apex compared to A. philippinensis (Marseul, 1854). Moreover, the presence of a single occipital fovea on the posterior portion of the head of A. coelestis (Marseul, 1857) (Fig. 11 ) is rather a remarkable character differentiating it from other species that has not been previously described.

Additional description.

Female genitalia: anterior portion of valvifers (Figs 38 , 39 ) paddle-shaped; gonocoxite (Fig. 40 ) elongate, almost 4 × as long as broad, not shovel-like, more narrowed on apical end; inner and outer surfaces differentiated; inner face weakly separated from outer face by elevated lateral ridge; sclerotized setae on apical half of outer face short and sparse; inner face with short setae and moderate setae; apex of gonocoxite with two teeth; gonostyli present, freely articulated; spermathecae multiple, consisting of four sacs; sacs gradually enlarged and elongate, not sclerotized.

Distribution.

Widely distributed in the Oriental Region including China, Taiwan, Ryukyu Islands (Japan). Also present in the Palearctic Region: Tajikistan and in the Afrotropical Region: Comoros Islands ( Mazur 2011).

Biology.

All individuals of A. coelestis (Marseul, 1857) were collected from dungs of cows and water buffaloes of lowland farms and pastures across all islands of the archipelago. This species may also seem to be moisture-specific, as they were observed to dwell only on more desiccated dungs during field collection.

Remarks.

Atholus coelestis (Marseul, 1857) (Fig. 2 ) is a widespread species across the Philippine archipelago showing a consistent morphology in all individuals examined. Atholus coelestis (Marseul, 1857) was re-described by Ôhara (1992) based on specimens collected from Ryukyu Islands (Japan). Here, SEM micrographs (Figs 9-14 ) and illustrations of female gonocoxite and valvifers (Figs 38-40 ) complement Ôhara’s description (1992).

Figures

Figures 1 - 6. Philippine Atholus, dorsal habitus 1 A. philippinensis (Marseul, 1854) [IC- 21 - 18] 2 A. coelestis (Marseul, 1857) [IC- 21 - 20] 3 A. torquatus (Marseul, 1854) [IC- 21 - 49] 4 A. pirithous (Marseul, 1873) [IC- 21 - 47] 5 A. nitidissimus Desbordes, 1925 [syntype image] 6 A. bakeri (Bickhardt, 1914) [syntype image, No. 1639]. Scale bar: 1.00 mm.

Figures 9 - 14. Atholus coelestis (Marseul, 1857) [IC- 21 - 20] 9 habitus, dorsal view 10 ditto, ventral view 11 head, dorsal view 12 propygidium and pygidium 13 protibia, dorsal view 14 ditto, ventral view.

Figures 38 - 40. Atholus coelestis (Marseul, 1857), female genitalia [IC- 21 - 11] 38 dorsal view 39 lateral view 40 dorsolateral view of gonocoxite. Scale bars: 0.20 mm.