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California Trapdoor Spider (Bothriocyrtum californicum)


Detailing the physical features, habits, territorial reach and other identifying qualities of the California Trapdoor Spider.


 Updated: 2/13/2018; Authored By Staff Writer; Content ¬©www.InsectIdentification.org



  California Trapdoor Spider  
Picture of California-Trapdoor-Spider
Picture of California-Trapdoor-Spider


An arachnid version of the Jack-in-the-Box toy, California Trapdoor Spiders are not at all amusing to the prey they startle.





California Trapdoor Spiders are native to Southern California. In many ways, they resemble smaller versions of tarantulas, but with shiny, hairless bodies. The whole spider is black except for the rusty brown abdomen. The large, round cephalothorax has a deep dimple in the center of it. The chelicerae (jaws) have spines on them that help this species with digging underground burrows. As is the case with most spiders, the female California Trapdoor spider is larger than the male. Males search for females during the winter months. Females lay their fertilized eggs at the bottom of the burrow. Once spiderlings hatch, they leave the burrow, sometimes sooner rather than later thanks to heavy spring rains.

These burrows can be more than 7 or 8 inches deep and serve as both a home and a trap. The top of the burrow opening is covered with a silk door that is hinged. As the years pass, spiders add more silk webbing to their doors. They may also collect debris and loose leaf litter, helping to camouflage its existence. Burrows are usually built into hillsides or cliff-faces, often facing direct sunlight for ambient warmth and usually near vegetation that is likely to attract insects. Under this door, the spider waits and, when it senses oncoming prey, it quickly lunges out of its burrow and catches the prey item. Once caught, the prey gets pulled down into the trap and restrained in the burrow by both the spider's body as well as silk-covered walls inside the burrow. The prey is consumed below the door, leaving no warning above for future passersby.
Basic Information
Common Name: California Trapdoor Spider
Other Name(s): Trapdoor Spider
Scientific Name: Bothriocyrtum californicum
Category: Spider


General Identification
Size (Adult; Length): 18mm to 33mm (0.70in to 1.29in)
Colorwheel Graphic
Identifying Colors: black; brown; yellow
Additional Descriptors: two-toned, pop-up, trapdoor, underground, ambush




Taxonomic Hierarchy
Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Ctenizidae
Genus: Bothriocyrtum
Species: californicum


Spider Anatomy (Typical)
Graphic showing basic parts of spider anatomy
1
Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.
2
Pedipalps: Small appendages near the mouth used as taste and smell organs.
3
Cephalothorax: Contains eyes, head, mouthparts, and legs.
4
Abdomen: Contains various organs related to digestion, reproduction, and web-making.
5
Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.
NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).


Territorial Reach (A-to-Z)
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed below as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections below indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canadian National Flag Graphic
Alberta
British Columbia
Manitoba
New Brunswick
Newfoundland and Labrador
Nova Scotia
Ontario
Prince Edward Island
Quebec
Saskatchewan
Mexican National Flag Graphic
Mexico


Territorial Area Map (Visual Reference Guide)
The map below showcases (in red) the states and territories of North America where the California Trapdoor Spider may be found (but is not limited to). This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan. Some species are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America.
Alaska  
Hawaii  
Prince Edward Is.  
State of Alabama graphic
State of Arizona graphic
State of Arkansas graphic
State of California graphic
State of Colorado graphic
State of Delware graphic
State of Florida graphic
State of Georgia graphic
State of Idaho graphic
State of Illinois graphic
State of Indiana graphic
State of Iowa graphic
State of Kansas graphic
State of Kentucky graphic
State of Louisiana graphic
State of Maine graphic
State of Maryland graphic
State of Michigan graphic
State of Minnesota graphic
State of Mississippi graphic
State of Missouri graphic
State of Montana graphic
State of Nebraska graphic
State of Nevada graphic
State of New England graphic
State of New Jersey graphic
State of New Mexico graphic
State of New York graphic
State of North Carolina graphic
State of North Dakota graphic
State of Ohio graphic
State of Oklahoma graphic
State of Oregon graphic
State of Pennsylvania graphic
State of South Carolina graphic
State of South Dakota graphic
State of Tennessee graphic
State of Texas graphic
State of Utah graphic
State of Virginia graphic
State of Washington graphic
State of West Virginia graphic
State of Wisconsin graphic
State of Wyoming graphic
Canadian territory of Alberta graphic
Canadian territory of British Columbia graphic
Canadian territory of Manitoba graphic
Canadian territory of New Brunswick graphic
Canadian territory of Newfoundland and Labrador graphic
Canadian territory of Ontario graphic
Canadian territory of Quebec graphic
Canadian territory of Saskatchewan graphic
Territory map graphic of the country of Mexico
Contiguous United States shape map layer graphic


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