Saprinus Erichson, 1834

Lackner, Tomas & Leschen, Richard A. B., 2017, A monograph of the Australopacific Saprininae (Coleoptera, Histeridae), ZooKeys 689, pp. 1-263 : 69-70

Saprinus Erichson, 1834 Figs 301, 302-310, 311-319, 320, 321-329, 330-336, 337, 338-343, 344-352, 353, 354-362, 363-371, 372, 373-381, 382-388, 389, 390-398, 399-407, 408, 409-414, 415-421, 422, 423-431, 432-438, 439, 440-448, 449-457, 458, 459-467, 468-476, 477, 478-486, 487-493, 494, 495-503, 504-510, 511, 512-520, 521-527, 528, 529-537, 538-546, 547, 548-556, 557-564, 565, 566-577, 578-584, 585, 586-594, 595-602, 603, 604-611, 612-618, 753, 755, 758, 759, 760, 761, 762, 763, 764, 765

Saprinus Erichson, 1834: 172. Type species Hister nitidulus Fabricius, 1801 (= Saprinus semistriatus (L.G. Scriba, 1790)), designated by Westwood (1838): 22.

Diagnosis.

Some members of Saprinus are the largest of the Australian saprinines with specimens of S. (S.) viridanus measuring up to 6.70 mm (PEL). The genus is also the most species-rich; it contains 18 species, including 4 newly described and 2 introduced species. All Australopacific species (with the exception of S. detritus , S. pseudodetritus , and S. chathamensis from New Zealand/Chatham Islands, and S. nitiduloides Fairmaire, 1883 from New Britain/Solomon Islands and S. artensis Marseul, 1862 from New Caledonia that are dark brown) are characterized by strong metallic luster on the dorsum of their bodies, especially on elytra, and absence of red, orange or yellow elytral patches (often present in Palaearctic, Oriental and African species). Likewise, all have complete frontal stria (with the exception of S. grandiclava from New Guinea and two newly described species from the Chatham Islands). The frontal stria is usually widely interrupted in the Palaearctic or African species and is used to diagnose the Palaearctic members of Saprinus . One species, S. viridipennis (Australia), lacks carinal prosternal striae and two species, S. grandiclava (New Guinea) and S. viridanus (Australia), share unusually large, circular antennal clubs.

An aedeagal peculiarity among Australopacific Saprinus is the presence of well-separated parameres (see also below; e.g. Fig. 475) in the Australian endemic species S. amethystinus Lewis, 1900, S. australis (Boisduval, 1835), S. laetus Erichson, 1834, and S. tyrrhenus Blackburn, 1903. The three New Zealand endemics, as well as S. grandiclava Kanaar, 1989 (endemic to New Guinea), have their parameres separated in the apical half and are more approximate than in the Australian species (Fig. 456).

Biology.

Species of Saprinus are typical volant predators with a preference for open grasslands and xerothermic habitats where they prey upon fly larvae found in decomposing organic matter, such as mammalian dung or carcasses ( Lackner 2010). Their large and well-developed sensory patches on the ventral side of their antennal clubs probably enable them to locate the carrion from a long distance (but these are lacking in S. grandiclava ). The natural history of several rare species ( S. grandiclava , S. amethystinus and S. tyrrhenus ) is completely unknown. S. rarus sp. n. was collected in the nest of the arboreal Tree termite ( Nasutitermes walkeri (Hill, 1942)) and is presumed to be a specialised termitophile.

Distribution.

There are eighteen species of Australopacific Saprinus : nine native and two introduced ( S. chalcites and S. cupreus ) are known from Australia; three species of Saprinus are present in New Zealand/Chatham Islands; New Caledonia has one endemic and one non-endemic species. New Guinea has a single endemic species, with two other, non-endemic congeners. We describe one endemic species from the Kiribati atoll (Figs 753, 755, 758-765).

Remarks.

Australopacific species of the genus Saprinus differ from the similar-looking species Notosaprinus irinus (Marseul, 1862) by the presence of lateral prosternal striae (usually both carinal and lateral prosternal striae are present). See discussion of Notosaprinus for more details. The genus Saprinus is the most species-rich genus of the subfamily (see e.g. Lackner 2010 or Mazur 2011 for details) with the bulk of its representatives occurring in the Palaearctic and Afrotropical Regions. Although moderately diverse also in the Oriental (Indo-Malayan) and Nearctic Regions, Saprinus of the Australopacific Region with 16 native species are rather species-poor when compared to their counterparts from the other regions. Only the Neotropical Region, with only 7 known species has fewer than Australopacific Region.

Based on the structure of the aedeagus there are two main groups of Australopacific Saprinus : in each group there are eight species with widely separated parameres and with fused parameres. Regarding the group of species with fused parameres, the following species are morphologically very similar: S. cyaneus cyaneus , S. artensis , S. nitiduloides and S. pacificus (compare Figs 335, 420, 493 and 510). Based on their overall similarities, including the structure of male genitalia we believe that they likely share a recent common ancestor that probably reached the region from the north, since a subspecies of S. cyaneus , S. cyaneus auricollis , is distributed also in the Indo-Malayan Region up to Southern Japan. These species can possibly be regarded among the so-called northern invaders, sensu Mitchell and Bouchard (2008). Another species with fused parameres, Saprinus splendens , is widely distributed in the tropical regions of Africa/Arabian peninsula and the Oriental (Indo-Malayan) Region as far east and north as Japan, and its occurrence in the Australopacific Region (Australia and Marianna Islands) is not surprising. The three remaining species with fused parameres ( S. rarus , S. viridanus , and S. viridipennis ) are Australian endemics. Saprinus rarus has a uniquely triangulate dilated and thickened antennal scape (Fig. 529), strongly dilated tibiae (Fig. 536) and elongate body shape (Fig. 528), features that are probably reflecting its termitophilous lifestyle, and may protect it against termites (thickened antennal club and dilated tibiae protect larger space of body venter when in repose). S. viridipennis lacks the carinal prosternal striae entirely (Fig. 609; an autapomorphic feature within Saprinus ), while the antennal club of S. viridanus is unusually large and circular, resembling the form present in the New Guinean endemic S. grandiclava (compare Figs 460 and 586).

The remaining eight species with (widely) separate parameres (Australian S. amethystinus , S. australis , S. tyrrhenus , S. laetus ; New Guinean S. grandiclava and New Zealand S. detritus , S. pseudodetritus and S. chathamensis ) are unique among the 157 described species of Saprinus (sensu Mazur 2011): no other species of Saprinus have this character. In the published phylogenetic analysis of the senior author ( Lackner 2014d) only the type species of the genus, S. (S.) semistriatus , a taxon with fused parameres, was analysed. As noted above (see remarks section of Notosaprinus ), S. (S.) semistriatus was recovered sister to Notosaprinus irinus ; this clade itself was recovered sister to a larger clade containing North American Xerosaprinus , African Pilisaprinus and Paraphilothis , Middle-Asian Styphrus , Palaearctic Phaonius (itself subgenus of Saprinus ). None of these relatives of Saprinus possess separated parameres. On the other hand, two members of the genus Microsaprinus Kryzhanovskij, 1976 that was recovered in the aforementioned analysis closer to the root, possess separated parameres of the aedeagus (albeit not widely; see Secq and Secq 1995 for figures). Looking at the character value nodes of Saprinus near and even more distant relatives the basal aedeagal condition does not appear therefore to be the separated-parameres character state, with the single exception of the two Microsaprinus species.

Key to the Australopacific species of Saprinus Erichson, 1834