Bug FAQCornfield Bolas Spider
Mastophora hutchinsoni · Order: Araneae · Family: Araneidae
Also called: American Bolas Spider, Bolas spider
The female cornfield bolas spider has a large round, milky-white abdomen with brown markings and a smaller brown carapace, while males are much smaller. It lives in shrubs and short trees of the northeastern United States, builds webs there, and hunts nocturnal moths and bluegrass worms at night.
Source: Wikipedia
How to recognize it
The species shows extreme sexual dimorphism, with females much larger than males.
Source: Wikipedia
Size
Both sexes hatch with a cephalothorax about 0.5 mm wide, but females grow significantly larger than males.
Source: Wikipedia
Can it bite, sting or make you sick?
The venom of Mastophora is not recorded as dangerous to humans or large animals. Females use their venom to kill prey.
Source: Wikipedia
Where it lives
Leaves and twigs nearby are used as sites for their egg sacs.
Source: Wikipedia
Life cycle
Spiderlings hatch in the spring. Males reach adulthood in summer, while females mature in the fall.
Source: Wikipedia
When you see it
Females hunt in the evening at night, giving them a nocturnal hunting pattern. Mature males leave their webs and wait in the webs of developing females to mate.
Source: Wikipedia
Where it comes from
Mastophora hutchinsoni is found in the northeastern United States, a temperate region of North America.
Source: Wikipedia
Lookalikes
Unlike many orb-weavers, it does not build the typical two-dimensional orb web.
Source: Wikipedia
Where it is found in the US
Recorded in 22 of 51 states and DC. Most records: Ohio, Maryland, Pennsylvania, New York, Tennessee, Indiana, Kentucky, Virginia.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What does the cornfield bolas spider look like?
Females have a large milky-white, brown-spotted abdomen and a small brown carapace, while males are much smaller.
Source: Wikipedia
Where is Mastophora hutchinsoni found?
It lives in the northeastern United States and, as a genus, is widespread in subtropical regions such as Australia, South Africa, Asia and the Americas.
Source: Wikipedia
What do they eat?
Females hunt nocturnal moths of the Noctuidae family and bluegrass worms of the Pyralidae family.
Source: Wikipedia
Same family (Araneidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Mastophora_hutchinsoni
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-28 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-28.