FNZ 48 - Scaphidiinae (Insecta: Coleoptera: Staphylinidae) - Collecting and dissecting
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
The use of three standard collecting methods will ensure high capture rates and informative biological data for scaphidiines.
- Mass collections, made by sifting leaf litter and rotten wood and fungi, which is placed into Berlese funnels or Winkler extractors (Besuchet et al . 1987) produces a high yield of scaphidiines, especially wingless species.
- Flight intercept traps (FIT, such as those described by Peck & Davies 1980 and Masner & Goulet 1981) have been most useful for capturing specimens of flight-capable species. When set in prime habitats, consisting of fallen trees and leaf litter, FITs are very productive.
- Hand collecting from fungi, especially at night for nocturnal species, is the best method for capturing live material, making host associations, and locating larvae, which are usually concealed in frass-covered tunnels of Basidiomycetes or among sporocarps of Myxomyctes.
After material has been collected, labelled, and sorted, Ivan Lōbl uses a European method for extracting and mounting male genitalia. Males are identified and selected for dissection (recognised by the presence of modified protarsomeres that are slightly dilated and bear tenent setae, and some species may have a patch of setae on the metaventrite). The specimens are removed from their points or cards and placed into a weak solution of ammonium hydrate for up to 5 minutes to soften the sclerites (material removed directly from ethanol is easier to dissect). The specimen is removed from the ammonium hydrate and placed on moistened filter paper to limit mobility while dissecting. The aedeagus is removed using pins that are inserted into the tip of the abdomen. Once the aedeagus is extracted from the specimen, the rest of the body is air dried and remounted while the genitalia are placed into isopropyl alcohol. A smooth droplet of Canada balsam, diluted with xylene as necessary, is placed on an acetate card and, with a small pin dipped in balsam, the aedeagus is picked up from the alcohol and placed into the droplet and manipulated to the preferred orientation (usually some with the parameres down so that the internal sac is clearly visible and others in lateral view). The specimens are checked at 24 h intervals for orientation (using xylene for thinning) until the aedeagus is stabilised in the mount. The acetate card is pinned below the specimen and can be removed and easily observed with a compound microscope. It is important that the preparations and pins used for dissection are kept clean. The wingless species of Baeocera and Brachynopus are very compact and have elytra that are securely ventrally wrapped around the lateral portion of the abdomen - these are difficult to dissect and one should be careful with specimens from small series. Though dissected mouthparts and other structures can be mounted in the same way as the aedeagi, we examined microstructures mainly through whole mounts on permanent slide mounts according to the methods explained in Leschen & Lōbl (1995) and Leschen (2003).
The length of specimens is measured from the middle of the anterior pronotal margin to the inner apical angle of the elytra. The relative length ratio of the antennomeres is measured from both pinned and slide-mounted specimens, and microsculpture is described as seen in a stereomicroscope at high magnification.
Material examined is based mainly on specimens held in NZAC, but also in those collections listed in the acknowledgments. Lectotype, holotype, and syntype material is listed in the body of the text and additional material examined is listed in Appendix 1; 2-letter area codes follow Crosby et al . (1998). Label data of older type material is presented with its original syntax with comments in brackets ([ ]) and a slash (/) to indicate different labels. Lectotypes and paralectotypes are designated for species described by Broun and Redtenbacher to fix the use of their species names; a lectotype for a species was selected from all specimens identified from the original series and concluded to be syntypes.