An Annotated Checklist of the Spiders of Washington [1988]

Introduction


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[Rod Crawford has kindly allowed me to make his 1988 An Annotated Checklist of the Spiders of Washington available online. All of the good bits are his, all of the mistakes are mine.--Allyn Weaks]

 

PREFACE [2002]

Dear Readers:

Thanks to Allyn Weaks and tardigrade.org, the annotated checklist of Washington spiders resurfaces! However, readers should be warned that the text given here is an exact copy of the version published in 1988, and has not been updated in any way. An online version, which would be continuously updated, is certainly a possibility for the future, but I presently have no time to work on such a project.

The following document was published over 14 years ago, and is in many respects out of date. It is not yet unusably obsolete, but users should bear in mind a number of caveats. Further additions to the Burke Museum spider collection from throughout the state, as well as some new publications including previously unpublished Washington records from other collections, have added about 100 species to the previous total of 760, including described species, apparently undescribed species, and some whose identity is uncertain. A few of the named species previously recorded from Washington have proven to have been misidentified, or to be synonymous with other species.

A number of the species given in the published list as unidentified or new, have since that time been identified or described and named.

Washington occurrence has been confirmed for 15 of the 74 species previously recorded from the state only in literature.

Family and genus level classification work by many authors has resulted in a considerable number of name changes for Washington spider species. Some of these are well established, others are only recently proposed and not corroborated; I am in agreement with some and not with others. Anyone who wants the latest "accepted" name for any species should consult Platnick's online world spider catalog at:

http://research.amnh.org/entomology/spiders/catalog81-87/INTRO1.html

In the published version of this checklist that is reproduced here, I expressed a number of taxonomic opinions that were distinctly unpopular. As far as I know, these opinions are still unpopular, and you won't find many other spider taxonomists who agree with them. Nevertheless, they are mostly still my opinions, although I've changed my mind in a few cases.

Anyone seeking answers to specific questions, wanting research loans of Burke Museum specimens, etc., is welcome to communicate with me at tiso@u.washington.edu. However, I usually do not have time to send large amounts of information.

Finally, a word to arachnological beginners. If you are new to spider identification, please be aware that to identify even a single spider to species level with reasonable accuracy requires examining genitalia and other tiny body parts with a powerful microscope. Naive persons almost always assume that one identifies spiders by color or "markings" or whole-body appearance, and that the best tool for identification would be a set of photos of entire spider bodies. No such luck! Trying to use whole-body photos for species level identification of spiders, might be compared with trying to construct a computer microchip using a baseball bat. It can't be done, even by an expert.

Rod Crawford, Burke Museum, Seattle, USA tiso@u.washington.edu
29 November 2002

 

Burke Museum
Contributions in
Anthropology and Natural History No. 5

An Annotated Checklist
of the Spiders of Washington

Rodney L. Crawford

Burke Museum of Natural History and Culture
Box 353010
University of Washington
Seattle, WA 98195-3010

ABSTRACT

A checklist is presented of 760 spider species currently known from Washington State; 393 are first verifiable records from Washington, 14 are first records from the United States, and 4 are first records from North America. Each entry includes reference to the best illustrated description and a list of coded Washington localities according to a 0.1° decimal geographic (latitude-longitude) grid. Records are based on the Burke Museum (University of Washington) collection, excepting the 74 species not represented there, and will serve as a guide to that collection. About 160 undescribed or unidentified species are included under reference numbers keyed to the collection; 93 of these are Linyphiidae. Entries are extensively annotated with taxonomic remarks and clarifications of past errors; included are 14 new combinations, 11 new synonyms, 14 rejected synonymies, and 3 changes in status for species-group names. An appendix lists 70 species whose past Washington records are incorrect or unverifiable. To date, this is the longest published spider species list for any comparable temperate zone area.

New combinations proposed: Phlattothrata parva (Kulczynski), sub Typhochrestus; Scotinotylus autor (Chamberlin), sub Scironis; Scotinotylus columbia (Chamberlin), sub Lophomma; Sisis plesius (Chamberlin), sub Minyriolus; Coreorgonal petulcus (Millidge), sub Scotinotylus; Entelecara sombra (Chamberlin and Ivie), sub Mythoplastoides; Hybauchenidium cymbadentatum (Crosby and Bishop), sub Hybocoptus; Meioneta ferosa (Chamberlin and Ivie), sub Gnathantes; Poeciloneta fructuosa (Keyserling), sub Linyphia and Lepthyphantes; Poeciloneta berthae (Levi and Levi), sub Lepthyphantes; Poeciloneta aggressa (Chamberlin and Ivie), sub Lepthyphantes; Saaristoa sammamish (Levi and Levi), sub Lepthyphantes; Kaestneria rufula (Hackman), sub Bathyphantes; Habronattus kubai (Griswold), sub Pellenes. New synonyms: Psilochorus fluvius Exline = P. hesperus Gertsch and Ivie; Metepeira lanei Exline = M. foxi Gertsch and Ivie; Erigone labra Crosby and Bishop = E. metlakatla Crosby and Bishop = E. aletris Crosby and Bishop; Typhochrestus jeniseicus Eskov = Semljicola barbigera (L. Koch); Scotinotylus bipoculatus Millidge = S. bicavatus Millidge; Walckenaeria septentrionalis Millidge = W. columbia Millidge; Gnathantes Chamberlin and Ivie = Meioneta Hull; Coniphantes Ivie = Kaestneria Wiehle; Pityohyphantes vancouveranus Chamberlin and Ivie = P. rubrofasciatus (Keyserling); Dendryphantes pallidus Exline = Metaphidippus albeolus Chamberlin and Ivie. New status is given to Pelecopsis sculpta digna Chamberlin and Ivie; Dolomedes triton scapularis C. Koch; Cybaeus tius Chamberlin and Ivie. Rejected synonymy: Eboria Falconer ≠ Semljicola Strand; Phlattothrata Crosby and Bishop ≠ Tapinocyba Simon; Mythoplastoides Crosby and Bishop ≠ Entelecara Simon; Coreorgonal Bishop and Crosby ≠ Scotinotylus Simon; Neriene Blackwall ≠ Linyphia Latreille; Hypsosinga variabilis (Emerton) ≠ H. pygmaea (Sundevall); Dismodicus modicus Chamberlin and Ivie ≠ D. decemoculatus (Emerton) ≠ D. variegatus Jackson ≠ D. bifrons (Blackwall); Entelecara sombra (Chamberlin and Ivie) ≠ E. media Kulczynski; Bathyphantes keenii (Emerton) ≠ B. reprobus (Kulczynski); Trochosa pratensis (Emerton) ≠ T. terricola Thorell; Misumenops lepidus (Thorell) ≠ M. celer (Hentz); Habronattus kubai (Griswold) ≠ H. sansoni (Emerton).

 

INTRODUCTION

Regional species checklists are useful tools for the taxonomist, the ecologist, and the biogeographer. They aid identification by indicating what species are likely to be found in a given area, provide locality records for use in distribution studies, serve as a data source for comparisons of species richness, and have many other applications. Yet up-to-date lists of spider species are available for very few areas in North America, and the only recent checklist for any western state of the U.S. is that of Allred and Kaston (1983), listing 621 species from Utah (including 54 unidentified). The present list is the first fruit of a 15-year taxonomic study of Washington spiders with their geographic and environmental distributions, whose ultimate goal is a comprehensive monograph.

The first, and to date the only, published checklist of Washington spiders is that of Worley (1932), who recorded 173 nominal species, drawn from his own collections in the San Juan Islands, material collected by Professor Trevor Kincaid beginning in 1889 (Hatch 1950), and records from literature. Also listed were 18 species whose occurrence in the state was expected. Worley's introductory statement, "The spider fauna of the State of Washington is fairly well known," is a noteworthy example of overconfidence. In an unpublished doctoral dissertation on five spider families, Exline (1936b) added 30 species for a total of 203. Since that time there has been no comprehensive list of Washington spiders.

The bulk of the Exline spiders, including those families not treated in her dissertation, are deposited in the Exline-Peck Collection, recently transferred to the California Academy of Sciences, Frizzell Laboratory for Arachnological Research. Various records of spiders from Washington in generic and family revisions of the last few decades have come largely from this source, from some Kincaid material at the Museum of Comparative Zoology, Harvard University, and from occasional visits to the state by nonresident collectors. A set of duplicates from the Exline collection furnished the seed for the present Burke Museum spider holdings, which now include more extensive collections by myself, Mr. J. Robert Thomson, and numerous occasional contributors, to a current total of over 50,000 specimens. I hope this paper will serve as a guide to that collection for taxonomic researchers or persons seeking other kinds of specimen data; thus, I have excluded literature records and specimens deposited elsewhere, except for species I have not seen and a few specimens, formerly here, that have been given to the Museum of Comparative Zoology (abbreviated MCZ in the checklist). Records of species I have not seen are exclusively from literature.

Species richness of spiders. This paper records 760 spider species from Washington, an area of 172,416 km2. About 393 of these species are here recorded from the state for the first time. I believe this to be the longest published species list for any comparable temperate zone area. In comparing species lists, the difficulty of separating collection intensity from actual richness must be borne in mind. West et al. (1984) recorded only 433 spider species from British Columbia (644,389 km 2), but I suspect that the true total for this province is comparable to that for Washington, its neighbor to the south. Palmgren (1977) listed 598 spider species from Finland (337,000 km2), but 425 (71%) of these were the product of an intensive study by Palmgren (1972) of only about 100 km2, with fairly uniform climate and environment, at the southern tip of Finland. The only area in North America covered by a thorough spider monograph is southern New England (Kaston 1948, 1977). Kaston (1977) cited 688 spider species from all New England, whose area of 163,043 km2 is comparable to that of Washington. Perhaps the best-studied spider fauna in the world is that of the British Isles (about 314,400 km2), whence Merrett et al. (1985) listed 622 species. One can be fairly certain that actual spider species richness in these better-collected areas is substantially lower than in Washington.

Compared to Britain or New England, Washington contains a much greater diversity of habitats, all of them undersampled. West of the Cascade Mountains, the near-ubiquitous moist coniferous forests constitute a habitat unique to this region. In the mountains are significant areas of alpine tundra together with extensive and varied subalpine habitats. The spider fauna of the forested eastern slope of the Cascades shows Californian influence; east of the Cascades are diverse steppe and semidesert habitats with Great Basin faunal influence; Rocky Mountain fauna may be found in the Selkirks and the Blue Mountains, in the northeast and southeast corners of the state respectively. As pointed out by Palmgren (1972), the number of species in a collection is proportional to the logarithm of the number of specimens, so that the nearer the approach to completeness, the greater the collection effort required for each addition. The present list must be very far from complete, since the effort of adding to it has not increased noticeably. With further sampling the list of Washington spider species will certainly exceed 800, and may eventually reach 1,000.

 

CHECKLIST FEATURES

Nomenclature. The names of family and generic taxa used in this checklist are largely those used by Brignoli (1983). In some cases, however, a more conservative nomenclature has been adopted; in each such case I have given reasons for my preference. Species-group names are based on the latest taxonomic revision or equivalent literature. New and unidentified species are indicated by arbitrary numbers (e.g., as Antrodiaetus sp. #1), which are repeated in Burke Museum records and collection labels, and will be cited in synonymy of future descriptions. Although new species descriptions are beyond the scope of a checklist, an indication of the depository of these specimens should be helpful to specialists doing revisions, and gives a more accurate picture of species richness. A few of these will probably prove synonymous with other species in the list. Species uncertainly identified are indicated by the abbreviation nr. or by quotation marks. Authors of all species are given, but dates of description omitted; these are available in the standard catalogues (Bonnet 1945-1961; Brignoli 1983). A number of nomenclatural changes have been made, based on my unpublished research. These include new combinations, changes in status, new synonyms, revalidated synonyms, rejected synonymies, and corrected misidentifications; each is identified in boldface capitals to the right of the name affected and briefly justified in comments under that entry. Most of these changes have not yet been tested by examination of type specimens and are not intended to be definitive. They are presented here to make my present ideas available to others more rapidly than would be possible through full, separate publication.

Species for which this is the first verifiable Washington record are so indicated by the symbol §to the left of the name. New records are claimed even where there is a previous record, if the latter is deemed unverifiable. Species listed from Washington by Worley (1932) are cited on the second line of the entry with the name used by Worley, in the format: Hexura picea of W. This will serve as a cross-reference to the older literature and allow continued access to Worley's useful microhabitat data.

The sequence of families is approximately the traditional one. Within families, the sequence follows that adopted in the Burke Museum collection, a compromise between tradition and the placing together of similar taxa. In most genera and families covered by recent revisions, the sequence follows the revision. This system is at least less arbritrary than alphabetical order, though individual entries may be less easily found. An index to genera will be found at the back.

One cannot compile a list of this sort without noticing that current standards of nomenclatural literacy have decreased markedly from those of previous generations. Taxonomy differs from other sciences in that to be competent, one must be a good scholar as well as a good scientist. Poor scholarship is shown by careless treatment of bibliographic and nomenclatural details, by lack of attention to prior literature old and new, by failure properly to latinize names of new taxa, and by failure to follow the recommendations, as well as the mandatory rules, of the International Code of Zoological Nomenclature. It is essential that anyone naming new taxa be familiar with Appendix D of the ICZN, "Recommendations on the Formation of Names," as well as provisions in the body of the Code such as 31A, on avoidance of personal names (this includes many geographic names) as nouns in apposition. This provision has often been violated to no good purpose. Names of classical origin are still much to be preferred.

The latest (1985) edition of the ICZN reverses the policy of most previous editions on the endings of patronymic species names (Art. 31a). Under the new code, the ending used in the original description, whether —i or —ii, is to be conserved. I have tried to use the correct original spellings for all patronymics in this checklist. Most were checked against the original description; where this was not accessible, I gleaned the original spelling from Bonnet (1945-1961).

Taxonomic references. On the second line of each entry I have cited the publication(s) currently most useful in identification. In most cases these are revisions, but often it is necessary to refer to original descriptions. Unfortunately, in a few groups no available literature is satisfactory for identification without careful individual study. Many spider species have been described from only one sex. In these cases I have indicated whether the other sex is available in the Burke Museum collection.

Localities. Concluding each entry is a list of Washington localities for the species, abbreviated as described below. All are based on Burke Museum specimens, except where otherwise indicated (by a bibliographic citation or museum abbreviation). Localities are cited, not by name, but by coordinates of the Decimal Geographic Grid (Crawford 1983a, 1983b). Briefly, in this system each locality is indicated by geographic latitude and longitude coordinates with fractions of degrees expressed as decimals (e.g., 46.5° rather than 46° 30'). Use of three decimal digits specifies a locality to within about 100 m, a degree of precision not possible with traditional forms of locality data. In particular, citation of localities by "nearest town" (West et al. 1984 and many others) has little scientific value, since the area where a given town is "nearest" is amorphous, subjective, and incapable of precise definition.

For the purpose of this list only, all coordinates are rounded to the nearest 0.1°, and resulting redundant records omitted. Decimal geographic coordinates are always rounded downward, so that coordinates always represent the southeast corner of the grid space containing the locality. Thus, 46.199° would be rounded to 46.1° rather than 46.2°. In Washington, a 0.1° grid space measures about 11 km by 7.5 km. Locality data ambiguous at the 0.1° level (e.g., "Seattle" which covers at least eight 0.1° grid spaces) are spelled out, with or without a parenthetic grid interpretation, or omitted.

Anyone who in future may desire full localities or other details for any of these records will be able to refer to the Burke Museum's collection and records, which are organized by their grid coordinates so that specimens so cited can easily be located. Although all localities are rounded to 0.1° here, the original specimen data is in most cases accurate to 0.001°. Depending on latitude, this specifies an area of 5000-10000 m2. For comparison, a locality given by U.S. Public Land section represents 2.3 million m2 (1 mi2), and most "nearest town" locality descriptions can be interpreted as representing 1000 million m 2or more.

To save space in this checklist, coordinates in each record have been abbreviated to a 4-digit number containing the ones and tenths digits of the latitude, followed by those of the longitude. Thus, 46.3° N, 123.1° W becomes 6331; 48.5° N, 118.7° W becomes 8587. This abbreviation system would be ambiguous if extended beyond the borders of Washington, but it happens that the range of coordinates represented by the state allows no duplication. The records are listed in order, first, from south to north; then, within each tenth degree of latitude, from east to west. Figure 1 shows the state of Washington with county outlines and 0.1° grid lines. Readers are invited to copy this map and plot the distributions of species of interest to them; they will find it surprisingly easy. Any map of Washington showing one-degree lines will allow correlation of grid spaces with towns and other geographic features.

Citation of literature records, which I have done only for species not in the Burke Museum collection, raises difficult questions. All too frequently, records have been cited without clear indication of specimen depositories. Such records are not verifiable and therefore have little scientific value. Taxonomists are human, and most taxonomic reports (including this one) probably contain misidentifications. Even correct identifications become obsolete when more sibling species are discovered. Statements about distribution, a standard feature of taxonomic reports, must be supported by published verifiable data if they are to fulfill the scientific criterion of reproducibility. This is also true of maps; several recent reports have given records as map dots only, with no text reference to any but type localities. No one can trace the source of these dots, and the localities they represent are a matter for conjecture. If space was the consideration in omitting the detailed records, how much better to omit the bulky and expensive maps, valueless without supporting data.

Of spider species recorded from Washington in literature, I have included only those I have seen or that are apparently verifiable. Others are relegated to an appendix together with species whose published Washington records are believed by myself or others to be erroneous.

 

ACKNOWLEDGEMENTS

I must first express gratitude to the late Harriet Exline for leaving a portion of her collection at the Burke Museum, which formed a starting point for my own arachnological work; and to Professor Melville H. Hatch, who first encouraged both Exline and myself to pursue the study of Washington spiders. Besides J. R. Thomson and I, the following recent collectors have each added more than 60 specimens to the Burke Museum spider collection: C. J. Becker, D. Carroll, S. J. Collman, W. Cone, L. Corpus, D. H. Mann, J. Nelson, R. E. Nelson, D. R. Paulson, J. P. Pelham, M. A. Peterson, C. Stoner, and P. M. Sugg. A few identifications were made by F. A. Coyle, T. Kronestedt, R. E. Leech, H. W. Levi, W. Maddison, and N. I. Platnick. G. B. Edwards looked up data for me at the Florida State Collection of Arthropods. B. R. Vogel loaned lycosid specimens and R. G. Snazell donated valuable British comparison specimens. Wayne Maddison provided extensive assistance with the salticid portion of the checklist. Reviewers' comments on an earlier draft were most helpful in several areas.

 

SYMBOLS AND ABBREVIATIONS

§ First verifiable Washington record
M Male
F Female
MCZ Museum of Comparative Zoology, Harvard University (immediate preceding record)
UWBM Thomas Burke Memorial Washington State Museum, University of Washington
ICZN International Code of Zoological Nomenclature, Third Edition (International Union of Biological Sciences, 1985)
Ref.: Reference to currently most useful description(s)
W Worley (1932)

Burke Museum Contributions in Anthropology and Natural History is a series of occasional papers publishing the results of research within the Museum's areas of interest: the anthropology, archaeology, geology, paleontology, and zoology of Washington State, the Pacific Northwest, and the Pacific Region.

The Burke Museum

The Thomas Burke Memorial Washington State Museum, named for Seattle's pioneer judge Thomas Burke, has it's roots in the founding of the Young Naturalists' Society in 1879. Recognized as the Washington State Museum in 1899, the Burke has become the largest museum of natural history and anthropology in the Pacific Northwest. To further the increase of knowledge in the Museum's area of interest, Museum staff and other scholars undertake research focussing on the Burke's five million specimens and on allied collections here and abroad. Research results are published is several Museum series.


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