Subgenus Kingius Franz

Kingius Franz in Newton & Franz (1998): 153. New name for Heterognathus King, 1864 .

Heterognathus King, 1864: 96 . Preoccupied, not Girard (1854) (Pisces); not Schmarda (1859) (Rotifera), not Rey (1888) ( Coleoptera: Histeridae). Type species: Heterognathus carinatus King, 1864 (des. Franz, 1975: 274). Synonymized with Cholerus by Csiki, 1919; as synonym of Scydmaenus in Fauvel, 1885: 182, but as separate subgenus in Franz (1975).

Emended diagnosis of Kingius . Scydmaenus with the following features: (1) antennal club virtually dimerous (Fig. 78); (2) all flagellomeres symmetrical or nearly so (Fig. 78); (3) submentum without lateral lobes (Fig. 77); (4) pronotum with median longitudinal antebasal carina, lacking antebasal pits (Fig. 76); (5) basisternal region of prosternum distinctly longer than procoxal rests (Fig. 77); (6) elytra lacking basal foveae (Fig. 76); mesocoxae narrowly separated by carinate mesoventral process, posteriorly fused with subtrapezoidal anterior metaventral process (Fig. 79); (7) metanepisterna largely fused with metaventrite (Fig. 79); (8) metaventral intermetacoxal process short and broad, with concave posterior margin, about as wide as one metacoxa; (9) male protarsi slightly broadened and with tenent setae on ventral surface of tarsomeres 1–3; and (10) aedeagus lacking lateral subapical lobes, with minute dorsal setae in apical region.

Remarks. King (1864) described the genus Heterognathus and defined it primarily by the asymmetrical mandibles: the right one with a bifid preapical tooth, and the left one with two teeth. He also described the maxillary palpomere 4 as “ minuto globoso ” (although “subglobose” would better match the dome-shaped structure), and several other characters, all matching world species of what is now recognized as Scydmaenus . Franz (1975) designated Heterognathus carinatus as the type species for the King’s genus, and placed Heterognathus as a subgenus of Scydmaenus . Franz’s (1975) diagnosis of Heterognathus (later replaced by Kingius) was based on the characters found in the type species. However, he lists in one paragraph features that demonstrate that Heterognathus is identical with Scydmaenus, and at the same time those that justify placing H. carinatus in a separate subgenus. It is impossible to extract subgeneric diagnostic characters from this description. However, such a diagnosis can be compiled from the characters used in the identification key for subgenera of Scydmaenus given in Franz (1975) on p. 273. The Franz’s diagnosis includes: (1) pronotum with median longitudinal antebasal carina; (2) antennae with antennomeres 6–8 transverse and 9 small, and with only dimerous clubs; and (3) metanepisterna demarcated from metaventrite by a sharply marked suture. In fact, the last character was incorrect, as in Scydmaenus carinatus the metanepisterna are largely fused with the metaventrite (Fig. 79), and a poorly visible suture delimiting these structures is developed only near anterior and posterior regions of the lateroventral metathorax. As a result, Kingius (= Heterognathus) cannot be identified using the Franz’s key.

Composition, distribution and biology. Kingius includes only two endemic Australian species, S. carinatus (King) and S. formicarum Franz. Both have been collected with ants, but the ant species remains undetermined ( S. carinatus was found “in the nest of small black ants”, according to King (1864)).

Identification key to males and females of Scydmaenus (Kingius)

1 Antennomere 10 distinctly transverse (Fig. 78); BL> 1.7 mm .......................... Scydmaenus carinatus (King)

- Antennomere 10 as long as broad (Fig. 90); BL <1.5 mm ........................... Scydmaenus formicarum Franz