FNZ 48 - Scaphidiinae (Insecta: Coleoptera: Staphylinidae) - Mycophagy
Löbl, I; Leschen, RAB 2003. Scaphidiinae (Insecta: Coleoptera: Staphylinidae). Fauna of New Zealand 48, 94 pages.
(
ISSN 0111-5383 (print),
;
no.
48.
ISBN 0-478-09353-5 (print),
).
Published 18 Nov 2003
ZooBank: http://zoobank.org/References/FDA38B33-D656-46CB-9406-CA03D26DC811
Mycophagy
Mycophagy is not a common feature among the largely saprophagous and predaceous oxyteline group of staphylinids, though it is a behaviour shared by all members of Scaphidiinae (Lawrence & Newton 1982; Newton 1984; Hansen 1997b). Associated with this shift to mycophagy is a suite of morphological and behavioral adaptations that include novel mouthpart structures and the building of faecal canopies by larvae that feed on relatively hard fungi (Newton 1984, 1991; Lawrence 1988; Leschen 1993, 1996; Hanley 1996). Scaphidiines are associated with fungal growth in leaf litter, rotten logs, and rotting vegetation, and, likewise, the inquilines of African and Asia are associated only with termites that build fungal gardens.
Host records for New Zealand scaphidiines are poorly known, though one of us (RABL) has focussed efforts on collecting from fungi. For some of the taxa reported in this study, the pattern of host use matches that for congeneric taxa in other regions. Many species are specialists on slime moulds (Lawrence & Newton 1980; Newton & Stephenson 1990), whereas others occur on relatively persistent wood-rotting fungi (Newton 1984; Ashe 1984; Leschen 1988). These two classes are also basically related to morphological features seen in the larval mouthparts. Many species of Baeocera are strictly associated with Myxomycetes, though there is no apparent specialisation on any one taxon of myxomycete. This is true for Baeocera actuosa , for which host records are numerous. In some cases, adults may use a wide array of hosts unrelated to the larval host, for example, B. actuosa, where adults are not restricted to slime moulds, and yet the larvae are. Larvae of Baeocera have a fan-shaped pseudomola (see Leschen 1993) that they use for puncturing or grinding the fungal spores of slime moulds.
Brachynopus latus and B. scutellaris have been collected mainly on resupinate corticioid and polyporoid genera (e.g., Schizopora) though records for stipitate or bracken polyporoids exist (e.g., Coltricia). These two species are part of an entire guild of specialist beetles in New Zealand restricted largely to resupinate fungi that grow on the undersides of rotting branches. The larvae of these two species build canopy retreats (Fig. 83) that can be seen very clearly on the fungi on which they feed. These larvae feed mainly on the hymenium or hyphae of basidiomycetes, do not specialise on spore feeding, and have a pseudomola composed of elongate spines.
A case of monophagy may occur in Scaphisoma hanseni, which is restricted mainly to the polypore Phellinus kamahi , where adults may be present in large numbers. The larvae of this species have not been collected, which suggests that oviposition may be very restrictive or occurs on an entirely different fungal substrate.
Brachynopus and Scaphisoma adults have a radulate galea (Fig. 75, 78, 81, 88, 89), composed of rows of rake-like spines that may function in the removal of rather tough fungal tissue. This is in contrast to the brush-like galea present in Baeocera which is a rather common feature throughout Coleoptera and may be related, at least in Baeocera , to spore feeding. Mycophagy in New Zealand Coleoptera will be discussed at greater length in a separate publication by RABL.