FNZ 53 - Harpalini (Insecta: Coleoptera: Carabidae: Harpalinae) - Methods and conventions
Larochelle, A; Larivière, M-C 2005. Harpalini (Insecta: Coleoptera: Carabidae: Harpalinae). Fauna of New Zealand 53, 160 pages.
(
ISSN 0111-5383 (print),
;
no.
53.
ISBN 0-478-09369-1 (print),
).
Published 04 Jul 2005
ZooBank: http://zoobank.org/References/5A8BF6BE-EA73-4476-8C81-E4F00709AC9B
Methods and conventions
Materials
This revision is based on 12 years of extensive field work carried out by the authors in over 500 localities, a survey of the literature up to May 2004, and the recording of information associated with over 5350 adult specimens from the following entomological museums and collections:
AMNZ Auckland Institute and Museum, Auckland, New Zealand.
ANIC Australian National Insect Collection, Canberra, Australia.
BBNZ B. I. P. Barratt private collection, Dunedin, New Zealand.
BMNH The Natural History Museum, London, U.K.
CMNH Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, U.S.A.
CMNZ Canterbury Museum, Christchurch, New Zealand.
FMNH Field Museum of Natural History, Chicago, Illinois, U.S.A.
ITNZ J. I. Townsend private collection, Levin, New Zealand.
JNNZ J. Nunn private collection, Dunedin, New Zealand.
LUNZ Entomology Research Museum, Lincoln University, Lincoln, New Zealand.
MCSN Musei Civico di Storia Naturale, Genova, Italy.
MNHN Muséum National d’Histoire Naturelle, Paris, France.
MONZ Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand.
NZAC New Zealand Arthropod Collection, Landcare Research, Auckland, New Zealand.
OMNZ Otago Museum, Dunedin, New Zealand
PHNZ P. Howe private collection, Timaru, New Zealand.
UCNZ Department of Zoology, University of Canterbury, Christchurch, New Zealand.
Specimen-based information from NZAC is being databased and will be made available online on the NZAC NZBUGS website (http://www.landcareresearch.co.nz/).
Collecting and preparation
Adults of Harpalini are generally collected by hand by turning ground debris. However, special techniques are used to collect large series or population samples for quantitative studies. These include (in order of decreasing usage): pitfall trapping, turning logs and stones, raking or sifting the leaf litter (especially for small species), treading vegetation into water, digging at the base of plants (e.g., Lupinus), pouring water over ground, treading soil with the feet, sweeping the vegetation, using Malaise traps, collecting with a head lamp or torch (e.g., in caves; on trees at night), light trapping (especially for adventive species), sifting garden compost, and turning drift shore material. Pitfall trapping, especially in forests (along streams) and in coastal dunes is the most reliable method for assessing the presence, community composition, and locomotory activity of harpalines.
Adults are best preserved dry. All life stages can be collected in 70–75% ethanol. If a molecular study is intended, adults as well as immatures can be kept in 95–100% ethanol.
All specimens should be labelled with the locality (including area code: Crosby et al. 1976, 1998, and geographical coordinates such as latitude and longitude), collection date, collector’s name, and biological data (e.g., general habitat, microhabitat, behaviour).
Most features of the external morphology and the male genitalia can be viewed under an ordinary dissecting microscope. It is necessary to relax and dissect male specimens in order to study their genitalia.
Male genitalia can be dissected as follows. Pinned specimens (individually or in batches) are warmed for 5–10 minutes in hot alcohol (70–75% ethanol). Once softened, each specimen is transferred to a cavity slide containing ethanol. A pair of fine forceps is used to extract the male genitalia from the abdomen. This is done under the microscope by inserting the forceps into the anus, cutting through the lateral membranes that unite the last two tergites and ventrites, pulling out the aedeagus and associated genital ring, separating these structures from each other, and cleaning the aedeagus from any residues and detaching the parameres. The dissected genitalic structures are then transferred to a new cavity slide containing glycerol for further study. After examination, the male genitalia are mounted on cards or points and re-attached to original specimens for permanent storage.
Revision process
The main steps followed in the course of this study are listed here with the hope that this will help future students of Carabidae:
- Borrowing of adult specimens from all available entomological collections (private and institutional).
- Labelling of borrowed specimens with the acronyms of the lending collections.
- Grouping of specimens based on overall similarities and differences in external morphology.
- Grouping of recognised morphological units by areas of New Zealand (area codes of Crosby et al., 1976 & 1998) from North to South, West to East, and by offshore islands. This facilitates the evaluation of structural variation between and within populations across the geographic range of each putative species.
- Dissection of male genitalia from at least 5 populations per area. Additional specimens sometimes need to be dissected from some areas (e.g., from WA, WN, SD, NN) where a high degree of variation may be observed between and within populations. About 650 male specimens were dissected in the course of this study.
- Identification of putative species based on male genitalia and drawing of their genitalic features (lateral and dorsal views of aedeagus).
- Correlation of results from the genitalia study with characters of the external morphology at the species level (corroborated, when possible, by geographical and biological information).
- Photography of pronotum and whole insect for each species.
- Description of taxa based on a character list developed from previously published works, the study of population samples in steps 6 and 7, and the drafting of a description for one species (often the type species) from each described genus. This involves the description of each species in detail followed by the transfer of selected characters from the species descriptions to the generic descriptions.
- Comparing circumscribed species against the types of already described species and application of existing names or new names.
- Preparing identification keys from descriptions.
Taxonomically relevant characters
The characters presented in the descriptions are subsets of the totality of adult characters (about 100) studied, and represent the most important differences between, or variation amongst, closely related taxa. Characters or states of characters not mentioned in the species descriptions are as described in generic descriptions.
Body length was measured from apex of mandibles to apex of elytra (with the specimen in dorsal view), and is cited as a range.
Characters with the highest diagnostic value at the species level have been photographed or illustrated, including the most diagnostic aspects of the male genitalia. Most illustrations provided in this work represent the most commonly encountered state of a character. The user must allow some degree of variation when working with individual specimens.
The male genitalia offer the most stable characters and the ultimate criteria for species recognition. The second best diagnostic character for the majority of taxa is the configuration of the pronotum.
Although it is necessary to fully dissect male genitalia within the context of taxonomic revisions, it is often enough to partially pull out the apex of the aedeagus with a pin at the time of mounting specimens in order to see enough of the genitalia for identification.
Parameres of the aedeagus were found to vary little between species and were not illustrated. In the Harpalini, the internal sac of the male aedeagus is either armed (provided with scales, teeth, or spines) or unarmed. These conditions have been stated although not illustrated for each species. Illustrating these characters in detail would have required the eversion of the internal sac, which was beyond the scope of this revision. The female genitalia were not studied either. There was sufficient diagnostic information provided by other characters.
Identification keys
Keys are somewhat artificial. They are intended as an aid to identification, not a statement of the authors’ opinion on phylogenetic relations. Additional supporting characters (e.g., distribution) have sometimes been included between key couplets to help identification.
Illustrations and digital photographs
Illustrations (except habitus drawings and Fig. 114–225), including maps, were prepared from pencilled drafts that were digitised, finished, and laid out using the software package CorelDraw graphics suite. Colour photographs of whole insects and pronota were captured through a Leica MZ-12 stereomicroscope, a 3CCD video camera, a LeicaDC500 digital camera, and the increased-depth-of-field computer system Auto-Montage (Synoptics U.K.). Further photo-processing was done with the software packages PhotoShop and CorelDRAW graphics suite.
Generic concept
A genus should be a monophyletic group composed of one or more species separated from other genera by a decided gap. The phylogenetic framework to study Australasian Harpalini, however, is insufficiently elaborated to test this hypothesis for New Zealand genera. Consequently, existing generic concepts have in general been accepted. In addition, new genera are proposed for species not fitting the correlated character complex of species included in already described genera. Recognition of these generic taxa provides new hypotheses that will hopefully be tested by future students of the higher classification of Harpalini; this must be done on a world basis or at least in an Australasian context.
A cladistic analysis, preferably integrating morphological and genetic information, is needed to determine the phylogenetic position of New Zealand genera within the Harpalini. Only then can an attempt be made to decipher the evolutionary history of the New Zealand taxa, e.g., to confirm or reject the hypothesis that certain genera are Gondwana relicts, to reconstruct the sequence of speciation and colonisation events, and to understand their evolution in general or that of their habitat relationships.
Species concept
The species concept used here is biological, inferred from morphological characters (especially male genitalia) hypothesised to constitute barriers to interbreeding and hence to gene flow between the different species. This is corroborated, when possible, by geographic and biological information, but is not tested by genetic or ethological investigations. This species concept requires the assumption that reproductive (genetic) continuity or isolation among natural populations is evidenced by continuity or discontinuity in characters of external morphology and genital structures provided by the study of population samples.
As generally observed in Carabidae, the most important characters to discriminate Harpalini species are the male genital structures, particularly the aedeagus. In the majority of New Zealand genera, many external characters are found to vary within species, or the range of their variation overlaps with that of closely related species, and similarities or differences in external morphology are not always congruent with the study of genitalia. Accurate species identification is generally impossible without an examination of male aedeagus. Therefore, in most cases, females can only be reliably identified by association with males. Fortuitously, identification is facilitated by the fact that New Zealand species are largely allopatric.
Taxonomic arrangement
Further study of Australasian Harpalini is needed before phylogenetic relationships can be hypothesised. In this monograph, subtribes and genera are treated alphabetically while species are arranged according to their similarity in male genitalia and external morphology, which may or may not be indicative of phylogenetic relationships.
Biostatus
This is indicated for all genera and species (A=Adventive; E=Endemic; N=Native, not endemic). The biostatus categories used are defined in the Glossary (Appendix A, p. 89). A combination of criteria was used to assess whether taxa were adventive including: recency of first New Zealand record in the literature and collections; fit of current geographical and ecological distribution with recognised natural patterns, or similarity of such distribution with that of other adventive arthropods; and dispersal ability, especially in relation to flightlessness and distance from the nearest overseas populations.
Type data
The primary types of native species were examined. Such information is listed in the following format: type status (holotype, lectotype, etc.) followed by sex, acronym of entomological collection or museum serving as repository, and original label data with a forward slash (/) indicating a different label. Only type localities are provided for adventive species.
Geographic distribution
For New Zealand distribution records, the area codes of Crosby et al. (1976, 1998) are given in alphabetical order for the North Island, South Island, Stewart Island, and the Offshore Islands, respectively. When appropriate, the extralimital distribution (outside New Zealand and its offshore islands) is also included, as well as first New Zealand records of adventive species. Full distributional information is given for species known from ten (10) localities or fewer. Appendix B (p. 91) contains a list of the main collecting localities and their geographic coordinates.
Two-letter abbreviations for the area codes of Crosby et al. (1976, 1998) used in this publication are as follows (see Maps 1-3):
New Zealand. North Island: AK, Auckland; BP, Bay of Plenty; CL, Coromandel; GB, Gisborne; HB, Hawke’s Bay; ND, Northland; RI, Rangitikei; TK, Taranaki; TO, Taupo; WA, Wairarapa; WI, Wanganui; WN, Wellington; WO, Waikato. South Island: BR, Buller; CO, Central Otago; DN, Dunedin; FD, Fiordland; KA, Kaikoura; MC, Mid Canterbury; MK, Mackenzie; NC, North Canterbury; NN, Nelson; OL, Otago Lakes; SC, South Canterbury; SD, Marlborough Sounds; SL, Southland; WD, Westland. Stewart Island, SI. Offshore Islands: AN, Antipodes Islands; AU, Auckland Islands; BO, Bounty Islands; CA, Campbell Island; CH, Chatham Islands; KE, Kermadec Islands; SN, Snares Islands; TH, Three Kings Islands.
Maps summarising species distributions by areas of New Zealand are provided on pp. 147-153.
Material examined
This indicates the number of specimens examined and the acronym of their repositories.
Ecology, biology, and dispersal power
The information provided is based on specimen label data, field observations from the authors, and the literature. In order to eliminate spurious records an effort was made to summarise available information by using the smallest common denominator amongst the greatest number of observations for each species. The terminology and style of presentation adopted here follows Larochelle & Larivière (2001). Most technical terms are also defined in the glossary (Appendix A, p. 89).
References
Under References, only the most important references are given for each taxon, with an indication of their contents between parentheses.