The Arachnid Order Solifugae



Major Collections
Type DepositoriesPast Researchers
Present Researchers
Globel Survey/Inventory

Project Aims

Diversity Inventories

Morphology, Anatomy, Cytogenetic and Behavior Surveys

Higher Phylogeny, Classification and Biogeography

Revisionary Syntheses

Outreach Activities

Other Projects
Collecting Techniques
Preservation Techniques


Aims of the
Global Survey and Inventory of Solifugae

Diversity Inventories

Fieldwork Strategy: Field inventories of Solifugae will be conducted by senior personnel and trainees in four regions with greatest solifuge diversity (Afrotropical; Palearctic; Nearctic; Neotropical) during years 1–4, for several purposes: discovering new species and distribution records; improving the understanding of known species by increasing material available for taxonomic revisions; obtaining fresh material for DNA isolation, morphological, anatomical and cytogenetic study; recording behavioral observations and photographs of live animals.  Within the four regions, trips will be undertaken to countries where foreign collaborators are available to obtain permits from authorities, advise on field sites, and assist with logistics, as in prior expeditions to these countries by Prendini, Wharton and Gromov (Fig. 1, Table 1, below). Seventeen fieldtrips will be undertaken in 13 countries: Namibia (years 1–4); Kenya (year 1); South Africa (years 2, 4); Israel (year 1); Egypt (year 2); Turkey (year 3); Kazakstan (year 3); Turkmenistan and Uzbekistan (year 4); Mexico (years 1–3); U.S.A. (year 4); Argentina and Chile (year 3). Bird, Wharton and Prendini will lead trips to Namibia, Kenya and South Africa, respectively.  Gromov will lead trips to the Palearctic countries.  Cushing, Brookhart and Savary will lead trips in North America.  Prendini will lead the trip to South America.  Fieldwork in the Northern and Southern Hemispheres will alternate to coincide with the summer season, when solifuge activity is greatest.  Trip leaders will provide instruction in field methods to foreign collaborators and trainees, who will then continue collecting material throughout the project in return for operating expenses.  In several cases, such collecting is an extension of existing programs (EduVentures in Namibia; South African National Survey of Arachnida (SANSA) and South African Reptile Conservation Assessment (SARCA) in South Africa; Turkish Solifuge Survey).

Figure 1.  Approximate world distribution of Solifugae, indicating countries where fieldwork will be conducted (blue circles), ranked by richness.


Table 1. Generic and species richness of Solifugae in countries where solifuges will be collected (data from Harvey 2003, pers. comm.); years during which surveyed; and senior personnel, trainees and foreign collaborators involved (* denotes liaison for permits). Top ranked countries (on a scale of 152) in order of decreasing generic and species richness (percentages of the world fauna provided in parentheses).





Senior Personnel (Yrs)

Trainees (Yrs)

Foreign Collaborators (Yrs)



26 (18%)

121 (11%)

Prendini (Y1)

Bird*, EduVentures (Y14)




23 (16%)

60 (6%)


Gromov (Y1)

Lubin & Zonstein* (Y1)


South Africa

21 (15%)

154 (14%)

Prendini (Y2,4)

Gromov (Y2), SCSA (Y1–4)

Dippenaar*,Lotz, SARCA (1–4)



13 (9%)

29 (3%)

Gromov/Prendini (Y3)

Koç (Y1–4), NU student (Y1–2)

Karataş*, Koç (Y1–4)



12 (9%)

66 (6%)

Cushing/Brookhart/Savary (Y1–3)

UNAM students (Y1–4)

Francke* (Y1–4)



12 (9%)

37 (3%)

Wharton/Prendini (Y1)

Mwangi (Y1–4), Reddick (Y1–2)

Warui & Gordon* (Y1–4)



12 (9%)

28 (3%)

Prendini (Y3)

Ojanguren, González (Y1–4)

Peretti* (Y1–4)



11 (8%)

158 (14%)

Cushing/Brookhart/Savary (Y4)

DMNS volunteers (Y4)




10 (7%)

28 (3%)


Gromov (Y2)

El-Hennawy* (Y1–4)



9 (6%)

32 (3%)


Gromov* (Y4)




9 (6%)

28 (3%)


Gromov* (Y4)




8 (6%)

13 (1%)

Prendini (Y3)

Ojanguren, ULS students (Y3)

Cepeda & Pizarro* (Y1–4)



6 (4%)

17 (2%)


Gromov* (Y3)


Collecting Methods: Field sites within each country will be situated in areas of greatest known family, genus, and species diversity (e.g., Baja California, Mexico) or where target taxa can be collected (e.g., Ceromidae: Western Cape, South Africa).  Live trapping will be conducted to select specimens for DNA isolation, morphology, histology, and behavioral observations.  Pitfall trap transects will be established across suitable habitat types at each site.  Solifuges occur in highest concentration and diversity in dunes, riverine systems, washes, gravel plains, and rock outcrops.  Eight trap-arrays will be set per site, each at a different point along the habitat transect, to maximize catch diversity.  Each trap-array will consist of three drift-fences (10 m each in a Y-shape) with a pitfall at each end, two midway along each fence (one on each side), and a center pitfall (= 10 traps x 8 arrays = 80 traps total).  This number is manageable for one person and yields good samples of Solifugae based on results from Wharton (1987) and SARCA (a trap-array yields between 1 and 65 specimens, mean = 25, n = 12).  Other studies (Muma 1970, 1975, 1980; Griffin 1990;  Dean and Griffin 1993) used pitfall traps successfully to sample solifuges from different habitats, but used fewer, preservative traps over longer periods of time.  Depending on terrain and in-country logistics, blocks of 10–14 days will be scheduled for the fieldwork at each collecting site. Following the protocol developed by SARCA, traps will be run for a minimum of 8 days, giving 8 arrays x 10 traps/array x 8 days = 640 trap-days per site.  Fieldtrips will be 4 weeks in duration, allowing two sites to be sampled per fieldtrip (1280 trap-days per trip), and providing sufficient time to sort samples, collect by hand (important in rocky habitats), and train collaborators.  At each locality, traps will be checked morning and evening to gather nocturnal and diurnal solifuges.  UV light detection (portable UV lamps, each comprising two mercury-vapor tubes attached to a chromium parabolic reflector and powered by a rechargeable 7 Amp/hr, 12 V battery), a technique used with great success in collecting nocturnal Solifugae (which fluoresce in UV) in Africa and Asia (L. Prendini and A.V. Gromov, pers. obs.) will be undertaken each night.  Solifuges will be preserved after capture or maintained alive for behavioral studies.  Sufficient expertise will be present during each fieldtrip to select appropriate, identifiable species for behavioral and anatomical studies: Wharton, Prendini in Africa; Gromov in the Palearctic Region; Brookhart, Savary and Cushing in North America; Peretti in Argentina.  Incidental catches of other arachnids will be preserved in 95% ethanol and used for REVSYS, AToL and related projects. Incidentally-collected vertebrates and non-arachnid invertebrates will be released unless local collaborating scientists are interested in the material.

Preservation:  Specimens or lots (conspecifics collected at the same locality on the same date) will be field-sorted to morphospecies and numbered individually, by trap-array.  Those for morphological study will be preserved in 75% ethanol; for DNA isolation in 95-100% ethanol, flash-frozen in liquid nitrogen, or preserved in RNA-later® (depending on duration of trip and transportation restrictions), and cross-referenced with morphological vouchers from the same series (or specimen, if samples, e.g., legs, taken from singletons); those for behavioral, anatomical and cytogenetic studies maintained alive and preserved later in accordance with final use.

Documentation:  Geographical coordinates and elevation of collection localities will be recorded with portable Garmin® GPS devices, along with other data (locality, collector, date, habitat, collection method), habitat and habitus photos, and captured using laptops to reduce errors in transcription.

Long Term Storage and Archiving:  Type material will be deposited in institutions in the country of origin, when possible. AMNH and DMNS will serve as primary repositories for non-type material and, when possible, synoptic collections of all species will be deposited therein.  Synoptic collections of material will also be deposited in other US and foreign collections.  Tissue samples will be stored (in liquid nitrogen at -150°C) in the Ambrose Monell Collection for Molecular and Microbial Research, where many arachnid tissues already are housed.  

Museum Collections: Type and non-type specimens in the world’s major collections will be borrowed or examined in situ, and databased.  This will enable assessment of geographical variation and determination of characters consistent across the range of each morphospecies, facilitate identification of autapomorphies or unique diagnostic character combinations (for species delimitation) and synapomorphies (for phylogenetic analysis), and provide an accurate idea of past and present distributions by documenting known locality records.  Approximately 30,500 specimens or lots are housed in the world’s collections (see below).  Approximately 48% of this material is identified, and only 35% is databased.  The largest collections, including 50% of the world’s unprocessed material, are housed in southern Africa, while the bulk of the type specimens (54%) reside in European institutions.  See Major Collections for more detail.

Databasing:  Collection data will be captured in a customized, Darwin Core compliant specimen database developed at the American Museum of Natural History (AMNH) for an NSF-funded PBI: Miridae project, maintained on the AMNH server and in use for the REVSYS: Vaejovidae project.  Data entry is facilitated by a user-friendly interface allowing digital images, taxonomic, and geographical data to be entered or uploaded from anywhere.   This is ideal for databasing museum collections.  Each specimen or lot has a unique matrix-code identifier in the database, cross-referenced with an accession or catalog number at an official repository.  Each image is correlated with the identifier, and multiple images sub-coded, to facilitate movement between images and data.  A portal will be provided on, allowing users to search for records of particular taxa, with combinatorial requirements for regions or authorities, taxa from specific regions, coordinates for mapping distributions, and types described by an authority or housed in an institution.  Data and images will be available for databasing initiatives elsewhere, e.g., African Arachnid Database (AFRAD) and Israeli Invertebrates Database.

Imaging Type Specimens:  Gromov will travel to European, Russian and African collections to image type specimens and capture collection data, using the online database and a portable Nikon microscope and associated digital camera already purchased by DMNS as a grant match.  Gromov will photograph habitus (dorsal and ventral), ♂ flagellum, ♀ genital opercula, ctenidia, and other characters for producing and documenting the morphological data matrix for phylogenetic analysis, code type specimens for specific key characters, and sort, identify, and database unidentified material.

Retrospective Data Capture and Georeferencing:  Excluding newly collected material (databased and georeferenced on acquisition), and previously databased museum material, ca. 18,000 specimen-lots will be captured and georeferenced (see Major Collections).  Hardcopy gazetteers and topographical maps may be consulted, but electronic gazetteers (e.g., Columbia Gazetteer of the World, eGAZ, Fuzzy Gazetteer, Geographic Names Information System, GEOnet Names Server, Getty Thesaurus of Geographic Names, and  MapFinder), will mainly be used for georeferencing, assisted by GEOLocate, which allows large spatial data sets to be imported and automatically georeferenced within minutes to hours.  After coordinates have been assigned to locality data, a visualization and correction system allows users to refine results.  Precision will be assigned using codes for spatial resolution (decimal degrees, degrees/minutes, quarter-degree squares [QDS]) and method of acquisition (GPS, electronic gazetteer, map-reading).

GIS, Mapping and Spatial Analysis of Distributions:  Online interactive mapping of distributions will be possible via the specimen database, using tools developed by the team at Discover Life and implemented on the PBI: Miridae website.  For publication-quality mapping and spatial analysis with GIS, georeferenced point locality records will be exported from the database, screened for precision using codes assigned during data capture, imported to ArcView GIS 9.0 (ESRI, Redlands, CA) and converted to a point coverage or ShapeFile. ShapeFiles will be superimposed on polygon coverages of political boundaries and topography, e.g., the Digital Chart of the World to create distribution maps, or for spatial analysis. For example, ‘hotspot’ analyses quantify species richness and endemism at the QDS scale.  Overlay analyses ascertain whether patterns of distribution are related to environmental variables, determine ecological correlates of distributional ranges, and calculate statistics that assist in defining conservation status.  This will be achieved with spatial joins, which assign values from spatial datasets (point or polygon coverages) to ShapeFiles of point locality records, allowing further analysis with multivariate statistics.  Spatial datasets (coverages) of topography (elevation), geology, soil types, climatic variables, vegetation and land uses (including protected areas) will be obtained from existing sources, e.g., GTOPO, INEGI, USGS EROS Landsat Collection, NASA Landsat Images and Land Processes Archive Center (see here for links).  GIS will assist with modeling species distributions using GARP, identifying range-restricted species and conducting gap analysis ( to assess conservation status. Measures of species’ distributional ranges, e.g., number of QDS containing point locality records, area of polygons created by joining outermost records, number of records and area of distribution falling within protected areas, will be calculated to assign conservation status according to IUCN Red List criteria (IUCN 2001).


Dean, W.R.J. & Griffin, E.  1993.  Seasonal activity patterns and habitats in Solifugae (Arachnida) in the southern Karoo.  South African Journal of Zoology 28: 91–94.

Griffin, E. 1990. Seasonal activity, habitat selection and species richness of Solifugae (Arachnida) on the gravel plains of the central Namib Desert. Pp. 77–82. In Namib ecology: 25 years of Namib research (M.K. Seely, ed.). Transvaal Museum Monograph 7.

IUCN (International Union for the Conservation of Nature and Natural Resources). 2001. IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, UK. Available from: RLcats2001booklet.html.

Muma, M.H. 1970. An improved can trap. Notes of the Arachnologists of the Southwest 1: 16–18.

Muma, M.H. 1975. Long term can trapping for population analyses of ground-surface, arid-land arachnids. The Florida Entomologist 58: 257–270.

Muma, M.H. 1980. Comparison of three methods for estimating solpugid (Arachnida) populations. Journal of Arachnology 8: 267–270.

Wharton, R.A. 1987. Biology of the diurnal Metasolpuga picta (Kraepelin) (Solifugae, Solpugidae) compared with that of nocturnal species. Journal of Arachnology 14(3): 363–383.


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