FNZ 2 - Osoriinae (Insecta: Coleoptera: Staphylinidae) - Phylogeny
McColl, HP 1982. Osoriinae (Insecta: Coleoptera: Staphylinidae). Fauna of New Zealand 2, 96 pages.
( ISSN 0111-5383 (print), ; no. 02. ISBN 0-477-06688-7 (print), ). Published 23 Dec 1982
Comment about phylogenetic relationships within New Zealand's Osoriinae and between them and other osoriines must be speculative at this stage. However, I regard Nototrochus as being representative of a primitive stock, and Paratrochus as having evolved from this stock. Nototrochus retains eyes and wings, the copulatory piece (see 'Terminology') lacks a side process, sternites 7 and 8 of the male are modified, and the spermatheca is a well sclerotised capsule (Figures 82, 83, 118, 119, 154, and 157). Paratrochus shows secondary reduction of eyes and wings (Figure 1), commonly found in cryptozoic and particularly humus-dwelling beetles, e.g., the staphylinids Pseudopsis (Herman 1975), Anotylus, and Oxytelopsis (Hammond 1976), and seen in New Zealand in many coleopteran families (Anthribidae, Carabidae, Cerambycidae, Colydiidae, Curculionidae, Elateridae, Lucanidae, Scarabaeidae, and Tenebrionidae (Holloway 1963)).
Herman (1975) records polymorphic wing development for Pseudopsis monotoaria and P. obliterata, both North American; 30% of specimens of the latter have reduced wings, the rest are macropterous. New Zealand lucanids show varying degrees of wing reduction within a group of related species, but not within a species (Holloway 1963). Montane African species of Anotylus have marked modifications associated with loss of flight. These are extreme in A. (Oncoparia) leleupi and A. (O.) parasitus, which have vestigial elytra, reduced disc, and more or less contiguous mesocoxae (Hammond 1976). In Paratrochus this extreme condition is not reached - the elytra are short but not vestigial, the disc not markedly reduced (see Figure 117), and the mesocoxae are well separated. In Paratrochus the copulatory piece usually has a side process, which I regard as being an advance on the primitive state; involvement of sternite 7 in secondary sexual modification of the male is rare, and where it occurs is slight; and the spermatheca is at most only weakly sclerotised.