The data in current edition of the Catalogue of Life have been provided by 143 databases. Most datasets include one or more global species database sectors (GSDs), i.e. datasets being developed to cover all of the world's species in a particular group of organisms. A few datasets provide regional information for groups not yet covered globally. The datasets result from collaboration and editing by many expert taxonomists, whose names are found in the datasets themselves. A brief summary is listed below giving: database short and full names; home page on the web; the author(s) or editor(s); organisation; the group for which data are provided, preceded by its higher classification; and the number of species and infraspecific taxa included in this checklist.

Database Qualifiers
In the Catalogue of Life we introduce "Database Qualifiers" which shown in the interface. Qualifiers give users a quick guide to the reliability of presented data. Qualifiers have been given by authors/editors of each database and appear on the Database Details page, and alongside, with the database name on each Species Details page. Qualifiers reflect data reliability in the Catalogue of Life only, and are not applicable to the original view of the database throught its own website. Qualifiers include:

• Geographic Coverage (values G for "Global" and R for "Regional")
• Taxonomic Completeness (values 1 - 100%)
• Checklist Confidence (values , see below for details)
Caution! This data set does not contain a scrutinised taxonomic checklist, and in parts may be a list of names only. However, as the only available resource at the time, it was included in the Catalogue of Life to fill temporarily a major gap. See database abstract for more details.
Caution! This data set is a scrutinised taxonomic checklist, but is incomplete and at an early stage of its development. See database abstract for more details.
This is a well-scrutinised taxonomic checklist, but it is restricted to a subset of species by geography (regional database), or sector of biological discipline (e.g. thematic database in ecological area, conservation, quarantine, pest and disease control, medicine or molecular biology, etc). This data set was included in the Catalogue of Life to fill temporarily gaps at lower levels of the taxonomic classification (e.g. species, genera). See database abstract for more details.
This is a nearly complete and fully scrutinised taxonomic checklist with a good quality of expertise at the current stage of its development.
This is a complete and fully scrutinised taxonomic checklist for an entire taxon with a high quality of expertise and frequent updates, which covers nearly all known species diversity in the taxon worldwide.

Source database English name of the group Species descending
Systema Dipterorum Flies, mosquitoes, bots, midges and gnats 138,934
LepIndex: The Global Lepidoptera Names Index Butterflies and moths 136,981
World Plants: Synonymic Checklists of the Vascular Plants of the World NEW! 280 families of flowering plants 119,328
Species Fungorum UPDATED! Fungi; protozoan fungi; chromistan fungi 109,171
WCSP: World Checklist of Selected Plant Families 99 families of seed plants 106,715
WTaxa: Electronic Catalogue of Weevil names (Curculionoidea) Weevils 98,238
ITIS Global: The Integrated Taxonomic Information System UPDATED! Wide range of global taxonomic checklists of different taxa 81,439
ITIS Regional: The Integrated Taxonomic Information System Wide range of taxa in all kingdoms 48,532
Taxapad Ichneumonoidea Ichneumonid and braconid wasps 42,370
Scarabs: World Scarabaeidae Database UPDATED! Scarab beetles 37,592
CarabCat: Global database of ground beetles NEW! Ground beetles 37,406
SpidCat via ITIS: The World Spider Catalog Spiders 35,787
WoRMS Mollusca: World Marine Mollusca database UPDATED! Marine molluscs 35,030
TITAN: Cerambycidae database Longhorn beetles, timber beetles 33,140
FishBase UPDATED! Fishes 32,513
GCC: Global Compositae Checklist UPDATED! Aster or sunflower family 32,382
OrthopteraSF: Orthoptera Species File Grasshoppers, locusts, katydids, crickets 25,205
ITIS Bees: World Bee Checklist Bees 20,446
ILDIS World Database of Legumes Legumes 19,999
UCD: Universal Chalcidoidea Database Chalcidoid wasps 19,847
MOWD: Membracoidea of the World Database Treehoppers and leafhoppers 15,387
CCW: Catalogue of Craneflies of the World UPDATED! Craneflies 14,827
MOST: Moss TROPICOS Database Mosses 13,365
World Ferns: Checklist of Ferns and Lycophytes of the World NEW! Ferns and fern-allies 13,124
SysMyr: Systematic Myriapod Database UPDATED! Diplopods, pauropods and symphylans 12,635
FLOW: Fulgoromorpha Lists On the WEB Planthoppers 11,719
WoRMS Polychaeta: World Polychaeta database UPDATED! Bristle worms 11,115
HymIS: Hymenoptera Information System UPDATED! Crabronids, spider-hunting and rhopalosomatid wasps 11,096
URMO: UNESCO-IOC Register of Marine Organisms Many groups of marine invertebrates and chordates 10,383
WoRMS Isopoda: World Marine, Freshwater and Terrestrial Isopod Crustaceans database UPDATED! Pillbugs, slaters and woodlice 10,263
The Reptile Database UPDATED! Reptiles 9,789
Umbellifers: World Umbellifer Database Imbellifers, carrot or parsley family 9,330
CilCat: The World Ciliate Catalog Ciliates 8,699
LIAS: A Global Information System for Lichenized and Non-Lichenized Ascomycetes Lichens 8,683
WoRMS Porifera: World Porifera database UPDATED! Sponges 8,499
GloBIS (GART): Global Butterfly Information System UPDATED! Hairstreaks, blues, coppers, swallowtails and whites 8,101
ScaleNet: Systematic Database of the Scale Insects of the World Scale insects 7,090
WoRMS Brachyura: World List of marine Brachyura UPDATED! Crabs 7,031
BIOS: Bacteriology Insight Orienting System Bacteria, archaea 6,749
LDL Neuropterida Species of the World UPDATED! Lacewings, antlions, owlflies, fishflies, dobsonflies, snakeflies and relatives 6,424
ZOBODAT: Zoological-Botanical Database (Vespoidea) Vespid wasps 6,205
Odonata: Global Species Database of Odonata Dragonflies and damselflies 5,912
PsocodeaSF: Psocodea Species File Bark lices & parasitic lices 5,902
WoRMS Bryozoa: World List of Bryozoa UPDATED! Bryozoans, moss animals 5,656
SalticidDB: Global Species Database of Salticidae (Araneae) Jumping spiders 5,601
AphidSF: Aphid Species File Aphids and allied groups 5,117
MELnet: Melastomataceae.Net Melastomes 4,743
BlattodeaSF: Blattodea Species File Cockroaches 4,510
3i Typhlocybinae: 3i interactive keys and taxonomic databases, subfamily Typhlocybinae Leafhoppers 4,508
Brassicaceae species checklist and database Crucifers, mustard or cabbage family 3,778
MolluscaFW: World Checklist of Freshwater Mollusca Fresh water gastropods 3,767
WoRMS Hydrozoa: World Hydrozoa database UPDATED! Hydroids 3,526
PlecopteraSF: Plecoptera Species File Stoneflies 3,491
FADA Ephemeroptera: World checklist of freshwater Ephemeroptera species Mayflies 3,341
ChiloBase: A World Catalogue of Centipedes (Chilopoda) for the web Centipedes 3,146
CoreoideaSF: Coreoidea Species File Leatherbugs 3,054
PhasmidaSF: Phasmida Species File Stick and leaf insects 3,046
NZIB: New Zealand Inventory of Biodiversity Various animalian taxa from New Zealand 2,938
Dothideomycetes UPDATED! 2,858
ICTV/MSL: International Committee on Taxonomy of Viruses / Master Species List Viruses and subviral agents 2,480
COOL: Cercopoidea Organised On Line Froghoppers 2,461
Tineidae NHM: Global Taxonomic Database of Tineidae (Lepidoptera) Clothes-moths 2,443
AnnonBase: Annonaceae GSD UPDATED! Custard apples 2,441
SCaDs: Selected Caryophyllales databases NEW! 14 Caryophyllales families 2,439
Psyl'list: Psylloidea database Jumping plant lice 2,429
MantodeaSF: Mantodea Species File Praying mantids 2,424
Catalogue of Life China Various taxa from China 2,354
Lace Bugs Database (Hemiptera: Tingidae) NEW! Lace bugs 2,338
Mites GSDs: PhytoseiidBase Phytoseiid mites 2,186
IOPI Global Plant Checklist Cycads and 5 families of seed plants 2,146
3i Cicadellinae: 3i interactive keys and taxonomic databases, subfamily Cicadellinae Leafhoppers 2,137
WoRMS Ophiuroidea: World Ophiuroidea database UPDATED! Brittle stars and basket stars 2,074
Parhost: World Database of Fleas Fleas 2,047
ChenoBase: Chenopodiaceae GSD UPDATED! Goosefoot family 2,015
FADA Rotifera: Annotated checklist of the rotifers (Phylum Rotifera) Rotifers 2,014
WoRMS Monogenea: World list of Monogenea UPDATED! Monogenean flatworms 1,868
Global Gracillariidae: Global Taxonomic Database of Gracillariidae Gracillariid moths 1,855
WoRMS Asteroidea: World Asteroidea database UPDATED! Starfish or sea stars 1,854
WoRMS Trematoda: World list of Trematoda UPDATED! Flukes 1,785
WoRMS Holothuroidea: World List of Holothuroidea UPDATED! Sea cucumbers 1,714
WoRMS Cestoda: World List of Cestoda UPDATED! Tapeworms 1,583
The White-Files: Taxonomic checklist of the world’s whiteflies (Insecta: Hemiptera: Aleyrodidae) NEW! Whiteflies 1,555
WoRMS Cumacea: World Cumacea database UPDATED! Cumaceans or hooded shrimps 1,531
FADA Turbellaria: World checklist of freshwater Turbellaria species Planarians 1,449
Phyllachorales UPDATED! Tropical tar-spot fungi 1,364
WoRMS Tanaidacea: World List of Tanaidacea UPDATED! Tanaids 1,276
SpmWeb: Spider Mites Web Spider mites 1,265
WoRMS Nemertea: World Nemertea database UPDATED! Ribbon worms 1,252
FADA Bivalvia: World checklist of freshwater Bivalvia species Bivalves 1,127 An online nomenclatural information system of Eumycetozoa UPDATED! Slime moulds 1,111
Microsporidia: Unicellular spore-forming protozoan parasites NEW! Microsporidians 1,104
Solanaceae Source Nightshade genus 1,083
FADA Cladocera: World checklist of freshwater Cladocera species NEW! Water fleas 1,043
WoRMS Proseriata-Kalyptorhynchia: World database of Proseriata and Kalyptorhynchia UPDATED! Freeliving flatworms 1,011
WoRMS Echinoidea: World Echinoidea Database UPDATED! Sea urchins 1,006
EbenaBase: Ebenaceae GSD UPDATED! Ebony family 942
WoRMS Oligochaeta: World List of Marine Oligochaeta UPDATED! Earthworms, oligochaetes 912
Mites GSDs: TenuipalpidBase Tenuipalpid mites 887
AFD: Australian Faunal Directory (Pulmonata) Snails and slugs (some groups) 880
TicksBase Ticks 867
WoRMS Gastrotricha: World Gastrotricha Database UPDATED! Gastrotrichs or hairy backs 838
ELPT: Early Land Plants Today - Uniting Taxonomy, Nomenclature & Geography (liverworts and hornworts) Hornworts and liverworts 824
Zygomycetes UPDATED! Pin moulds and related fungi 786
Saccharomycetes UPDATED! Ascomycetous yeast forming fungi 745
Hexacorals: Hexacorallians of the World Sea anemones 738
ILDIS for i4Life (additional taxa) NEW! Legumes 688
BdelloideaBase: Bdellid & Cunaxid Databases UPDATED! Bdellid and cunaxid mites 668
Conifer Database UPDATED! Conifers 635
Strepsiptera Database: Global Strepsiptera Database Twisted-winged parasites 601
WoRMS Scaphopoda: World List of Scaphopoda UPDATED! Tusk shells 571
Rhytismatales UPDATED! Tar-spot fungi 507
Mites GSDs: OlogamasidBase Ologamasid mites 446
WoRMS Polycystina: World list of Polycystina (Radiolaria) UPDATED! Polycystines (radiolarian protists) 416
CIPA: Computer Aided Identification of Phlebotomine sandflies of Americas Phlebotomine sandflies 396
WoRMS Brachiopoda: World Brachiopoda database UPDATED! Lamp-shells 393
EmbiopteraSF: Embioptera Species File Webspinners 391
FADA Nematomorpha: World checklist of freshwater Nematomorpha species Freshwater hairworms 356
RJB Geranium: Geranium Taxonomic Information System Cranesbills, geraniums 345
Trichomycetes UPDATED! Fungi associated with Arthropods 312
LecyPages: The Lecythidaceae Pages Brazil nut family 311
Xylariaceae: Home of the Xylariaceae UPDATED! Fungi associated with dead wood 308
Tessaratomidae Database: Illustrated catalog of Tessaratomidae NEW! Tessaratomids 240
WoRMS Myxozoa: World list of Myxozoa UPDATED! Myxozoans 194
Droseraceae Database Sundew family 182
Glomeromycota UPDATED! Glomeromycota 166
Mites GSDs: RhodacaridBase Rhodacarid mites 145
WoRMS Chaetognatha: World list of Chaetognatha UPDATED! Arrow worms 131
WoRMS Gnathostomulida: World list of Gnathostomulida UPDATED! Gnathostomulids or jaw worms 97
ETI WBD: World Biodiversity Database (Euphausiacea) Krill 86
FADA Halacaridae: World checklist of freshwater Halacaridae species NEW! Aquatic mites 59
WoRMS Leptostraca: World List of Leptostraca UPDATED! Leptostraca 53
WoRMS Tantulocarida: World List of Tantulocarida UPDATED! Tantulocaridans 36
WoRMS Thermosbaenacea: World List of Thermosbaenacea UPDATED! Hot-springs shrimps 35
MBB: Moss Bug Base Moss bugs 32
LHD: Lacistemataceae Holistic Database Waits Numi plant family 25
WoRMS Remipedia: World Remipedia Database UPDATED! Remipedes 24
WoRMS Priapulida: World list of Priapulida UPDATED! Priapulid worms or penis worms 19
WoRMS Phoronida: World Phoronida database UPDATED! Horseshoe worms 16
WoRMS Mystacocarida: World List of Mystacocarida UPDATED! Mystacocarids 13
WoRMS Brachypoda: World List of Brachypoda UPDATED! Brachypods 12
WoRMS Bochusacea: World List of Bochusacea UPDATED! 5
WoRMS Xenoturbellida: World List of Xenoturbellida UPDATED! Xenoturbellids 2
WoRMS Placozoa: World Placozoa Database UPDATED! Placozoans or pancake animals 1
Species 2000 additional Common Names for the Catalogue of Life 0