New Zealand Entomologist, 1984, Vol. 8 The arrangement of insect collections: options and their merits LEWIS L. DEITZ Department of Entomology, Box 7613, North Carolina State University, Raleigh, NC 27695-7613 U.S.A. Abstract The relative merits of arranging insect collections systematically, alphabetically, or geographically are considered. Included also are discussions of incorporation versus segregation of special collections (type, voucher, teaching, and historical material) and of the main collection's dry, liquid, and slide components. Keywords: curation; arrangement of specimens; insect collections. INTRODUCTION Selecting an arrangement for an insect collection of even a few thousand specimens is no simpje matter. Over 900 families of living insects are recognized for the world (Parker 1982) and the number of species runs into the millions. To a large extent the arrangement of collection determines the availability and usefulness of its resources. Because rearranging a major insect collection effectively requires a great outlay of time and money, as well as some risk of damage, the choice of arrangement should be carefully evaluated before any changes are made. The stability as well as the utility of various arrangements must be considered. This paper explores some of the options and their merits. The best arrangement for any insect collection will depend on its primary uses. Taxonomic research collections, for example, tend to be arranged systematically. Agricultural reference collections may be arranged by crops. In reference collections used mostly to identify local material it is helpful to segregate species which occur only outside the region of interest. Teaching collections should show the relationships under study, but a random arrangement of specimens is desirable in a drawer of "unknowns" that students are to identify. Because of breakage and security risks, it is essential to limit access to research and reference collections and to maintain separate, expendable collections for most hands-on student use. Research and reference collections are indispensable tools for taxonomic study and identification, and they provide permanent documentation of our insect faunas. As such, they merit a commitment to long-term preservation (riot only protection against breakage, fire, and museum pests, but also optimum temperature and humidity control). In contrast, most individual specimens used for teaching are slated for destruction. Size and practicability are further consideration. The larger the collection, the more critical it is to select an appropriate arrangement. Vials, pinned material, and microscope slides all require different handling and storage. Liquid-stored specimens require periodic checks to avoid desiccation. In a small collection it might be helpful to store immatures in alcohol near the pinned adults of the same species, but a few vials scattered in a vast assemblage of dried material tend to be forgotten when it is time to "top up" the alcohol. Pinned and other dried specimens must be Paper No. 8876 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7613. Presented, in part, at a conference on curatorial techniques, Southeastern Branch Meeting, Entomological Society of America, Little Rock, Arkansas, 26 January 1983.
New Zealand Entomologist, 1984, Vol. 8 121 protected from dermestids and other pests, and microscope slides also require ' special storage to protect mounts from breakage, becoming stuck together, and the migration of specimens in fluid media which occurs if slides are stored on edge. So practical considerations usually dictate that the collection be divided into at least three sections: liquid, dried, and slide-mounted material. Although pinned specimens are possibly more easily arranged (and broken) than liquid or slide-mounted material, the kind of storage units selected (drawers with unit trays or Schmitt boxes; vial racks or vials in ointment jars; slide cabinets or slide boxes) will obviously affect the ease of arranging and rearranging material. Allowing ample space for growth throughout the collection can reduce the need for major rearrangements to accommodate new acquisitions. In pinned collections Jaques (1936) advised initially setting aside one-third of each drawer for expansion. THE RELATIVE MERITS OF SYSTEMATIC, ALPHABETIC, AND GEOGRAPHIC AR- RANGEMENTS A. A strictly systematic arrangement allows the easiest retrieval of an insect if one is familiar with its classification, but does not have its name precisely as listed in the collection. It aids identification, facilitating sight comparison as well as the use of taxonomic keys. It also facilitates the study and teaching of systematic relationships. Lastly, it aids in making a systematic inventory of the collection and in finding taxonomic gaps in the material. B. A strictly alphabetic arrangement allows the easiest retrival if one has an insect's name precisely as alphabetized, but is unfamiliar with its classification. It therefore facilitates retrieval by nonspecialists. Nevertheless, even simple nomenclatural changes may cause problems in retrieval and also necessitate major rearrangements. Alphabetic arrangement aids neither identification nor the study and teaching of relationships. It facilitates an inventory of the taxonomic level(s) alphabetized. C. A strictly geographic arrangement allows the easiest retrieval of material from a given geographic region; however, it may hinder retrieval of specific taxa, if members of the same taxon from different regions are dissociated. Athough geographic arrangement may or may not aid identification, it facilitates studying and teaching geographic relationships (but not systematic relationships). It also facilitates a geographic inventory of the collection and in identifying regional gaps in the collection. D. Other arrangements, such as by host or crop, have advantages and disadvantages that parallel those of arrangement by geographic region, and may be useful for specialized collections. Overall, systematic arrangement seems to have more advantages than either alphabetic or geographic, but one of the latter may be preferable in some cases. Often the best compromise combines all 3 approaches and again depends on the intended use of the collection. At least down to the family level, most curators adopt a largely systematic arrangement following some carefully selected classification or classifications. It is important that the specific plan followed be available to the users (Black 1975) and be indexed. Specimens identified only to the order level are placed at the end of the order - if identified only to family, at the end of the family, and so forth. Thus, taxa of uncertain position, as in a catalog, are generally placed at the end of the lowest taxon to which they are known to belong. It may be desirable to follow the systematic arrangement to the level of tribe or subtribe, especially in large groups where the higher classification is stable and useful in identification. At the generic and specific levels, however, the ease of retrieving from an alphabetic scheme usually outweighs the advantages of following a strictly systematic classification. Within
122 New Zealand Entomologist, 1984, Vol. 8 a species, it is often useful to group specimens geographicaly or by host (or by determiner if, regrettably, in identified series only the first specimen bears a determination label). In some state collections, unit trays holding in-state material bear a special coloured signal dot, and other zoogeographic colour codes indicate what regions are represented in each unit tray, drawer, or cabinet. Another geographic grouping is to keep local and exotic material in "parallel collections". For example, the exotic material may be kept at the end of each family or order - or, with shelf-stored specimens, exotic material may be kept on the top shelves above the related native groups, as in the New Zealand Arthropod Collection (Walker & Crosby 1979). In some insect collections. such as that of the Bisho~ Museum, the usercommunity is largely concerned with a variety of specific geographic areas. Here there are advantages to organizing the collection by a special locality code. Steffan (1977) described an alphanumeric code in which large units, such as the Pacific Basin, are indicated by two letters (PB), and smaller units are indicated by two numbers. For example, Micronesia is coded PB 04. The Bishop Museum follows a phylogenetic arrangement to the level of family, but within families most specimens are arranged first by the locality code, then alphabetically by genus and species (Steffan 1977). TYPE-MATERIAL To ensure maximum protection and accessibility (Recommendation 72D, International Code of Zoological Nomenclature, 2nd edition), many curators isolate holotypes, lectotypes, neotypes, and syntypes from the general collection. If isolated, types are less likely to be damaged through routine use, and they can be more quickly removed in the event of fire or other disaster. Types are a special case where arrangement by author of the species may be useful. Also, alphabetic arrangement by specific name makes sense here, because most requests to examine type-material include both specific name and author, even if present-day placement differs from that given in the original description. VOUCHER COLLECTIONS Conflicts occasionally develop when the researcher who deposits a voucher collection wants it kept as a unit for future reference. The curator', on the other hand, may wish to incorporate the material into the main collection where it will be more accessible - otherwise, one may have to check a dozen or more voucher collections, as well as the pinned, liquid, and slide divisions of the collection to fill loan requests. The curator can often win over the researcher by pointing out that coloured voucher labels (Fig. 1) allow quick retrieval of vouchers from other material. Yoshimoto (1978) recommended light green labels for vouchers. COLLECTIONS OF HISTORICAL VALUE Often, important collections of early workers or historical expeditions are poorly labeled. As with voucher specimens, all such material should be clearly and unambiguously labeled to identify its significance (Fig. 1). In some cases keeping these collections separate will facilitate the recognition of unmarked types or other valuable material. INCOMING COLLECTIONS Incoming, unsorted collections are probably best arranged either by locality or by accession or lot number. In the NCSU Insect Collection, we place pinned material which is sorted only to order in "receiving"drawers at the end of each order. I,
New Zealand Entomologist, 1984, Vol. 8 123 W[ Vl SOYBEAN RESEARCH NC AGR. EXP. STA. IN ETHANOL W.D.FUNKHOUSER Entomology Division COLLECTION DSIR New Zealand W.M.Maskel1 Collection Fig. 1 Examples of voucher, cross-reference, and special collection labels INDEXING, CROSS-REFERENCING, AND COLOUR CODES An excellent way to inform users of the arrangement followed in a collection is to post alphabetic and systematic indexes of the families and orders, including the various locations of the taxa in the collection. Ideally, such indexes would also include the location of specimen-related materials such as photographs, ecological, and field notes not indicated on data labels, reprints, and unpublished manuscripts on the material (Steffan 1977). Computerization should be considered where it is desirable to index all taxa in a large collection, but only if the collection is well organized and the range of data to be entered is restricted (Steffan 1977). Whatever the arrangement adopted, the use of cross-reference labels (Fig. 1) and zoogeographic colour codes (Table 1) can be of great assistance to users. In pinned collections removable header labels placed between or inside unit trays can be used to identify each taxon and the localities respresented (Jaques 1936). With this system narrow, coloured tapes are recommended to designate zoogeographic areas, while various coloured dots indicate the presence of primary types (red), local material, or other special designations. TABLE 1. Colour codes for zoo- Zoogeographic Region Colour Codes geographic regions used in entomo- BMNH USNM logical collections of the British Nearctic dark green red Museum (Natural History) Neotropical pale green green (BMNH), most sections, and the palearctic white silver United States National Museum of Afrotropical blue black Natural History (USNM). Madagascar purple Oriental yellow Indian yellow S.E. Asian orange Australian pink blue Oceanic brown gold/orange To indicate that material is on loan from a drawer or unit tray in the NCSU Insect Collection, we insert a large, orange-headed pin labeled with the borrower's name. Knowing the borrower's name, users can retrieve further details of the loan from our loan files. Departmental staff also place "personalized" loan pins in the collection when they remove material for prolonged study. SUMMARY AND CONCLUSIONS Utility, practicality, stability, and security are all of concern in arranging insect collections. Above all, the intended use of the collection should dictate the arrangement. In general, systematic arrangement seems to have more advantages than either strictly alphabetic or geographic grrangement. Nevertheless, ease of retrieval for noispecialists makes alphabetic organization attractive for understaffed collections. Also, if users are primarily interested in definite geographic - - - areas or hosts, these concerns may override other factors in selecting an arrangement. A combination of systematic, alphabetic, and geographic approaches often offers the best compromise.
124 New Zealand Entomologist, 1984, Vol. 8 Practicability in larger collections generally necessitates the segregation of liquid, dry, and slide material. To insure stability, it is essential to allow ample space for growth throughout the collection. For security reasons, material for hands-on teaching should be kept apart from the research and reference collections to which access should be limited: Access to type-material especially should be restricted. Regardless of the arrangement selected, posted indexes to the arrangement, crossreference labels to special collections, and zoogeographic colour codes can help to make the resources of a collection more accessible. ACKNOWLEDGMENTS For sharing helpful suggestions and information relevant to this paper, I thank J. K. Barnes, J. B. Chapin, T. K. Crosby, M. H. Farrier, R. C. Froeschner, W. J. Knight, H. H. Neunzig, C. S. Parron, and D. L. Stephan. LITERATURE CITED BLACK, C. G. (Chairman) 1975: Report of the ASC Council on Standards for Systematics Collrctions. Association of Systematics Collections newsletter 3(3): sprcial insert, 1-4. JAQ~JLS. H. E. 1936: Somr methods of labelling and housing large insect collections. Canadian entomologist 68(1): 1-7. PARKER. S. P. (editor). 1982: Synopsis and classzfication r?f living organisms New York, McGraw Hill. Volume 2. 1232 pp. SILI.I.AN. W. A. 1977. Collection managrment practices for increased user accrssihility. Association of Systematics Collections newsletter 5(6): 65-66. WALKER. A. K.; T. K. CKOSBY, 1979: Thr prrparation and curation of insrcls. New Zealand Department of Scientific and Industrial Research information series 130: 1-55. YOSIIIMOTO, C. M. 1978: Voucher specimens for entomolocgy in North America. Bulletin of lhe Entomologzcal Soczety of America 24(2): 141-2.