Spinybacked orbweaver vs Arrowhead orbweaver
These two are easy to mix up. Here's how to tell a spinybacked orbweaver from an arrowhead orbweaver, and whether either one bites or stings.
Spinybacked orbweaver
Gasteracantha cancriformis
Arrowhead orbweaver
Verrucosa arenata
≠The key differences
Gasteracantha has a hard, flattened, white-and-black abdomen with spines; the arrowhead orbweaver has a softer triangular abdomen with a single pale arrowhead mark and no spines.
⚖︎Side by side
| Spinybacked orbweaver | Arrowhead orbweaver | |
|---|---|---|
| To humans | Mild venom | Non-toxic |
| Size | Females 6-9 mm body length (abdomen wider including spines); males 3-4 mm body length | Females about 5-10 mm body length; males about 3-5 mm |
| Colours | White, Bright red, Yellow, Black, Orange | Orange, Reddish-brown, Cream/Off-white, Dark brown/black |
| Family | Araneidae | Araneidae |
| Habitat | Edges of woods, gardens, shrubs, hedgerows and other vegetation where they can anchor orb webs | Woodland edges, shrubby areas, gardens, and low vegetation where they can anchor vertical orb webs |
| Range | Southeastern United States through the Caribbean, Central America and much of South America | Eastern North America, from the eastern United States (and extreme southern Canada) south into Mexico and Central America |
| Active | Year-round in warm climates; most active during daylight and warm months | Active mid summer through autumn; mostly crepuscular to nocturnal when rebuilding and hunting, often present at web during daylight |
| Pest? | No | No |
🔍How to spot a spinybacked orbweaver
- Wide, flattened abdomen with three pairs of stout spines (six spines total)
- Brightly coloured dorsal abdomen (white, yellow, orange or red) often with black spots or margins
- Small body with orb web spun in low shrubs or garden edges; females much larger and more conspicuous than males
🔍How to spot an arrowhead orbweaver
- Look for an angular, triangular abdomen with a large pale yellow or white arrowhead-shaped triangle on a brown background.
- Rests at the web hub with its head pointing upward; males are smaller and duller.
- Found on vertical orb webs in low shrubs, tall grasses or garden vegetation—spot the web first, then the spider near the center or at the web edge.
?Frequently asked questions
What is the difference between a spinybacked orbweaver and an arrowhead orbweaver?
Gasteracantha has a hard, flattened, white-and-black abdomen with spines; the arrowhead orbweaver has a softer triangular abdomen with a single pale arrowhead mark and no spines.
Is a spinybacked orbweaver or an arrowhead orbweaver more dangerous?
Spinybacked orbweaver: Mild venom. Arrowhead orbweaver: Non-toxic. Not dangerous to people. Arrowhead orbweavers are not dangerous to people.
Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.