Spiders of North Carolina

Arachnids of North Carolina

Order:
Scientific Name: Common Name:		Family (Alpha):

Gasteracantha cancriformis - Spinybacked orbweaver Araneidae Members:			NC Records	BugGuide Account	Public View

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Distribution Records
PDF

Vetting Levels

Adult phenology:
High Mountains (HM) ≥ 4,000 ft.
Low Mountains (LM) < 4,000 ft.
Piedmont (Pd)
Coastal Plain (CP)

Click on graph to enlarge

synonym

taxonomic_comments

cancriformis (L), 'crab shaped'

species_comment

Crab Spider, Spiny Orbweaver Spider, Crab-like Orbweaver Spider, Crab-like Spiny Orbweaver Spider, Jewel Spider, Spiny-bellied Orbweaver, Jewel Box Spider, Smiley Face Spider, Crablike Spiny Orbweaver.

id_comments

A very distinctive spider with many color forms. Abdomen crab like with six spines around edge. Abdomen color can be white, yellowish to orange with dark spots, spines are tipped in black or red. Cephalathorax and legs are dark or black in color. The spinnerets are located on a raised tubercle under the abdomen, instead of the more normal position at the end of the abdomen. There is also a small projection from the underside of the abdomen that the male grasps while mating. Males are tiny are rarely seen. Males are much smaller than females, 2 to 3 mm long, and slightly longer than wide. Color is similar to the female, except the abdomen is gray with white spots. The large abdominal spines are lacking, although there are four or five posterior small hump

total_length

Small, female total body length 5.8-8.6 mm, male total body length 1.9-2.7 mm.

structural_features

The six spines do not sting, and are used as a deterrent to avian predators only. These spiders can be handled by the abdomen without injury, but can deliver a mild bite to humans.

silk_web

Large orb webs, up to 50 cm (about 20 inches), are built in shrubs and the low branches of trees as well as on structures. Web is built at an angle to perpendicular. Web has white bands of thick silk alternating on the major lines of the web. Forms web in the morning and sits head down in center of web throughout the day. This spider adds little tufts of silk to its web that likely attract prey. According to Florida's Fabulous Spiders(2) "these little flags serve a warning function to prevent birds from flying into the web, destroying it." When a small insect flies into the web, she moves toward it, then snaps the radii on either side of the insect. In order to secure the prey, the spider snaps more of the web around the area, then rushes toward the prey in order to determine its exact location and bite it before carrying it back to the central disk where she feeds.

fld_guide_descriptions

online_photos

prey

drosophilids, other small fly species, whiteflies, beetles, moths, etc.

predators

The spider eggs are often attacked by parasitoid wasps and flies. (Levi, 1978; Muma and Stone, 1971)

behavior

This species of spider does not live very long. In fact, the lifespan only lasts until reproduction, which usually takes place the spring following the winter when they hatched. Females die after producing an egg mass with 100-260 eggs, and males die six days after a complete cycle of sperm induction to the female. Egg sacs are usually attached to the underside of leaves, typically near the web. Egg sac is constructed with various colors of silk and includes a longitudinal dark green stripe. Males are sometimes found hanging from single silk lines near the webs of females. Laboratory studies of mating behavior show that males visit female webs, and use a 4-tap rhythmical-pattern drumming on the silk of the web. After several cautious approaches, males approach females, become strapped down with silk from the female, and copulate. Mating may take 35 minutes or more. After mating, the male remains on the female's web. Mating may occur repeatedly.

distribution_reference

technical_reference

Spiders of North America - Bradley; Spiders of the Carolinas – Gaddy; Bugguide

adult_id

1 identifiable by photo 2 identifiable by photo of specific features and/or supplementary info 3 identifiable from specimen only

abundance

Common

distribution_comments

Common throughout the coastal plain and piedmont. Found throughout the United States, emerging in spring, maturing in summer and surviving until the first frost, all year long during mild winters.

checklist_mt_high
>=4,000 ft.

Regular	Frequent	Infrequent	Occasional	Seldom	Frequency Regular – almost always observed on given visit; >=90% chance of observation Frequent – usually observed on a given visit; >=50%<90% chance of observation Infrequent – observed less than 50% of visits; >=25%<50% chance of observation Occasional – observed on only on a small minority of visits; >=10%<25% chance of observation Seldom – not usually seen on visits; <10% chance of observation These terms refer to visits to appropriate habitats made at appropriate times of the year, making use of common sampling/observation methods. Under those conditions, Frequency refers to the chance of observing at least one individual on a given visit made anywhere within a particular region, or over multiple visits to a single site.

checklist_mt_low
<4,000 ft.

Regular	Frequent	Infrequent	Occasional	Seldom

checklist_pd
Piedmont

Regular	Frequent	Infrequent	Occasional	Seldom

checklist_cp
Coastal Plain

Regular	Frequent	Infrequent	Occasional	Seldom

habitat

Woodland edges, shrubby vegetation, gardens, agricultural areas including orchards and citrus groves.

observation_methods

Visual observation, sweep netting and beat sheets.

state_protection

NHP_ranks

NHP_status

status_comments

Photo Gallery for Gasteracantha cancriformis Spinybacked orbweaver
	Recorded by: Kasie Lewis Iredell Co. Comment: A large web with an active adult	Recorded by: Kasie Lewis Iredell Co. Comment: A large web with an active adult
	Recorded by: Kasie Lewis Iredell Co. Comment: A large web with an active adult	Recorded by: Kane Alec Lawhorn Hyde Co. Comment: Saw about 10 individuals on the 1/2 mile loop trail. Picture of adult attached.
	Recorded by: Mark Basinger Wilson Co. Comment:	Recorded by: Brenda Vaughan Person Co. Comment: The web caught my attention first because it looked almost like water droplets spaced out on a string.
	Recorded by: Brenda Vaughan Person Co. Comment: The web caught my attention first because it looked almost like water droplets spaced out on a string.	Recorded by: Christie J Poling Nash Co. Comment:
	Recorded by: Christie J Poling Nash Co. Comment:	Recorded by: G. Newman; R. Newman Onslow Co. Comment: HABE
	Recorded by: Mark Basinger Rowan Co. Comment: Young, immature female	Recorded by: Mark Basinger Rowan Co. Comment: Young, immature female
	Recorded by: Mark Basinger Wilson Co. Comment:	Recorded by: Marissa Matthews Cabarrus Co. Comment:
	Recorded by: Mark BASINGER & Donald ZEPP Greene Co. Comment: Low orb web at roadside at edge of swampy woods	Recorded by: Terrell Tucker Moore Co. Comment: Spider spun web from house eaves.
	Recorded by: Yolanda Cristiani Pamlico Co. Comment:	Recorded by: Amanda J Wall Gaston Co. Comment: New this season! Never spotted this species in 30 years here.
	Recorded by: Amanda J Wall Gaston Co. Comment: New this season! Never spotted this species in 30 years here.	Recorded by: Amanda J Wall Gaston Co. Comment: New this season! Never spotted this species in 30 years here.
	Recorded by: Zachary Jones Pitt Co. Comment:	Recorded by: Brian Bockhahn Dare Co. Comment:
	Recorded by: Susan Schambach New Hanover Co. Comment:	Recorded by: Susan Schambach New Hanover Co. Comment:
	Recorded by: Marissa Durham Co. Comment:	Recorded by: Mark Basinger Brunswick Co. Comment:
	Recorded by: Mark Basinger Brunswick Co. Comment:	Recorded by: Mark Basinger Brunswick Co. Comment: This is a juvenile.
	Recorded by: Brandon Pike Union Co. Comment:	Recorded by: Mark Basinger Wilson Co. Comment:
	Recorded by: Mark Basinger Wilson Co. Comment:	Recorded by: Owen McConnell Durham Co. Comment:
	Recorded by: Jessica Sass Bertie Co. Comment: Building a web on my front porch	Recorded by: Jessica Sass Bertie Co. Comment: Building a web on my front porch
	Recorded by: R. Newman Carteret Co. Comment: FOMA	Recorded by: Travis McLain Anson Co. Comment: https://www.inaturalist.org/observations/141366625
	Recorded by: Mark Basinger Rowan Co. Comment:	Recorded by: Travis McLain Rowan Co. Comment: https://www.inaturalist.org/observations/141366625
	Recorded by: Marl Fox Onslow Co. Comment:	Recorded by: R. Newman Carteret Co. Comment: FOMA
	Recorded by: Stephanie Haverstick Harnett Co. Comment:	Recorded by: B.Fleming Carteret Co. Comment: FOMA - Black and white color var. @ -76.681804, 34.695282
	Recorded by: Kim STONE & Donald ZEPP Franklin Co. Comment:	Recorded by: David George Richmond Co. Comment:
	Recorded by: Brian Bockhahn New Hanover Co. Comment:	Recorded by: Jim Cabarrus Co. Comment: Residence back yard. Had been there 3 days. Bride says "begone". Moved to back of HOA.
	Recorded by: Jim Cabarrus Co. Comment: Residence back yard. Had been there 3 days. Bride says "begone". Moved to back of HOA.	Recorded by: Erich Hofmann Craven Co. Comment:
	Recorded by: Tracy S. Feldman Scotland Co. Comment:	Recorded by: Brian WAGONER & Donald ZEPP Cumberland Co. Comment:
	Recorded by: Brian WAGONER & Donald ZEPP Cumberland Co. Comment:	Recorded by: Susan O’Rourke Wake Co. Comment:
	Recorded by: Susan O’Rourke Wake Co. Comment:	Recorded by: Mark Shields Onslow Co. Comment:
	Recorded by: Shawn Tracy Johnston Co. Comment:	Recorded by: Brian Bockhahn Durham Co. Comment:
	Recorded by: Paul Brotcke Mecklenburg Co. Comment:	Recorded by: Paul Brotcke Mecklenburg Co. Comment:
	Recorded by: Julia A. Tennant Wake Co. Comment:	Recorded by: Julia A. Tennant Wake Co. Comment:
	Recorded by: Erich Hofmann and Kayla Weinfurther New Hanover Co. Comment:	Recorded by: Ken Kneidel Mecklenburg Co. Comment:
	Recorded by: Carol Tingley Chatham Co. Comment:	Recorded by: A. Pharr Wayne Co. Comment: CLNE
	Recorded by: J. Brown Dare Co. Comment: RUHI	Recorded by: Tracy S. Feldman Scotland Co. Comment:
	Recorded by: Tracy S. Feldman Scotland Co. Comment:	Recorded by: F. Williams, S. Williams Gates Co. Comment: MEMI - Mid-winter in complete web
	Recorded by: Brian Bockhahn Stokes Co. Comment:	Recorded by: J. Hawley Beaufort Co. Comment: GOCR
	Recorded by: j.wyche, n.dominick Gates Co. Comment: MEMI - on Cypress Point Trail	Recorded by: Brian Bockhahn Harnett Co. Comment:
	Recorded by: j.wyche Gates Co. Comment: MEMI - north boundary	Recorded by: F. Williams, S. Williams Gates Co. Comment: MEMI
	Recorded by: j.wyche Gates Co. Comment: MEMI - boundary line b/t Millpond Rd. & Silver Springs Rd.	Recorded by: F. Williams, S. Williams Camden Co. Comment: DISW - Egg case
	Recorded by: J. Wyche Gates Co. Comment: MEMI - 1 dropped from park visitor's gear onto the parking lot at the old canoe area; 1 in her web just S. of Millpond Bridge	Recorded by: j.wyche Gates Co. Comment: MEMI - old canoe area
	Recorded by: NEW Moore Co. Comment: WEWO - egg case on oak leaf	Recorded by: Jane Wyche Gates Co. Comment: MEMI - Cypress Point Trail
	Recorded by: Jane Wyche Gates Co. Comment: MEMI - on Cypress Point Trail	Recorded by: K. Bischof Beaufort Co. Comment: GOCR - Obs. Tar Kiln Trail.
	Recorded by: K. Bischof, J. Bischof, K. Bischof Beaufort Co. Comment: GOCR - Obs. along the Palmetto Boardwalk Trail adjacent to the Outdoor Classroom. @ -76.901604, 35.476599	Recorded by: Jane Wyche Gates Co. Comment: MEMI - with a very nice web in front of the old office building
	Recorded by: Dorothy E. Pugh New Hanover Co. Comment: CABE - Near white sandy trail not far from the Cape Fear River.	Recorded by: FKW, SBW Gates Co. Comment: MEMI - Near outhouse at canoe-in group site.
	Recorded by: S. Crocker Carteret Co. Comment: FOMA - This specimen is showing the white dorsum coloration with some red on the spines. Some specimens have spines that can be red, black or a variation of the two.	Recorded by: C.Helms Moore Co. Comment: WEWO - Web head high streched about 10' between two longleaf pines.
	Recorded by: R. Newman Carteret Co. Comment: FOMA	Recorded by: Scott Bolick Richmond Co. Comment:

Photo Gallery for Gasteracantha cancriformis Spinybacked orbweaver