Subgenus Parallomicrus Franz

Parallomicrus Franz, 1998 (in Newton & Franz, 1998): 153. New name for Allomicrus Franz, 1975.

Allomicrus Franz, 1971a: 101 (as subgenus of Scydmaenus; not as new; nomen nudum, no description). Note: Franz referred Allomicrus to a work published later (Franz 1975).

Allomicrus Franz, 1975: 284 (as subgenus of Scydmaenus). Preoccupied, not Gahan (1893) ( Coleoptera: Cerambycidae). Type species: Scydmaenus rufus Müller & Kunze, 1822 (des. orig.).

Diagnosis. Franz (1975) defined Parallomicrus (as Allomicrus) by the following characters: (1) lack of secondary sexual characters on the head and antennae; (2) the pronotum without antebasal pits; (3) elytra lacking basal impressions and humeral folds; (4) the metaventrite fused with metanepisterna, and (5) weakly broadened protarsi in males.

Remarks. All the above-mentioned characters are present in the type species of the subgenus and in two Australian species placed in Parallomicrus, except that Franz (1975) placed in Parallomicrus also S. inflatitibia, which has two pairs of distinct antebasal pronotal pits, and therefore does not match the Franz’s diagnosis of the subgenus. However, most of the diagnostic characters of Parallomicrus are reductions that can also be found in other subgenera. The only feature that is not a reduction (metanepisterna and metaventrite fused together) also occurs in other subgenera. Moreover, the type species differs from the two Australian species placed by Franz in Parallomicrus in the structure of the aedeagus. The status and diagnosis of Parallomicrus are here treated as unclear, and no attempt is made to redefine this subgenus. It is, however, necessary to redescribe the Australian species to facilitate identifications and to document their morphological structures, which will facilitate a future reclassification of Scydmaenus .

Composition, distribution and biology. Parallomicrus includes six species, but placement of most of them requires verification. The best studied is the Western Palaearctic type species of the subgenus, S. rufus Müller & Kunze, 1822, whose larva, feeding behavior and prey preferences were described in Jałoszyński (2015) and Jałoszyński & Olszanowski (2015). Species of Parallomicrus are distributed in Africa: Algeria, Tunisia; Asia: Lebanon, Turkey; Australia: continental Australia and Tasmania; Europe: Austria, Belgium, Bosnia & Herzegovina, Czech Rep., Denmark, Estonia, Finland, France, Great Britain, Germany, Greece, Hungary, Italy, Latvia, Netherlands, Norway, Poland, Portugal (Azores), Romania, European Russia, Slovakia, Spain, Sweden, Switzerland, Ukraine; Georgia; and Pacific islands: Fiji (Vanu Levu), and New Caledonia.

In Australia two species occur, S. inflatitibia Franz and S. myrmecobius Csiki. The latter has been collected in colonies of the ant Amblyopone australis Erichson.

Identification key to males of Australian Scydmaenus (Parallomicrus)

1 Pronotum with two pairs of antebasal pits; hind tibiae strongly modified, each with abrupt lateral elongate concavity on outer region and with subapical constriction demarcating short curved distal portion (Figs 118–119); antennomere 5 longer than 4 and 6; antennomere 11 less than twice as long as broad, with lateral outer margin bearing proximal angulate expansion (Fig. 120, right antenna); aedeagus with lateral subapical lobes broadly subtriangular, small (Fig. 121)..................................................................................................... Scydmaenus inflatitibia Franz

- Pronotum lacking antebasal pits; hind tibiae unmodified, slender (Fig. 113); antennomere 5 subequal to 4 and 6; antennomere 11 more than twice as long as broad, with lateral outer margin rounded (Fig. 112); aedeagus with lateral subapical lobes elongate subtrapezoidal, conspicuously long (Fig. 114)................................ Scydmaenus myrmecobius Csiki