Insect Identification
Insect Identification

Spiny Backed Orb Weaver - (Gasteracantha spp.)

Authored By Staff Writer | Last Updated: 8/13/2014

You can look, but don't touch the Spiny-backed Orbweaver spider. Those thorns help keep predators at bay.

The spines on the side of this female spider make it unique and easy to recognize. Males are considerably smaller than females and they lack the spines. There are a variety of species in this genus and colors vary.

Like other orb weavers, it creates a web that is circular in shape, only it has few or no spirals at the center of its web. Each night, a new web is spun to catch small insect prey. The spider stands up-side-down on the web.

Late in the year, the female will lay eggs that will grow throughout winter, hatching spiderlings in the spring. The oval-shaped egg sac is near the web, usually hidden underneath leaves. It may be white, green or yellowish, but it is woven of the spider's silk.

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Category: Spider
Common name: Spiny Backed Orb Weaver
Scientific Name: Gasteracantha spp.
Other Names: Crablike Spiny Orb Weaver Spider

  Kingdom: Animalia
   Phylum: Arthropoda
    Class: Arachnida
     Order: Araneae
      Family: Araneidae
       Genus: Gasteracantha
        Species: spp.

Adult Size (Length): 2mm to 10mm (0.08in to 0.39in)

Identifying Colors: orange; black; white; yellow; red

Additional Descriptors: spikes, flat, spines, thorns, spots, biting, venomous

North American Reach (Though Not Limited To*): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; 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

* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.