Bug Identifier
Fishing spider (likely dark fishing spider)
Community identification

Fishing spider (likely dark fishing spider)

Dolomedes tenebrosus

Order & Family
Araneae, Pisauridae (nursery-web spiders)
Size
Body length is typically 15–26 mm; females are larger, with leg spans commonly reaching 45–75 mm.
See this bug in the Encyclopedia

Natural Habitat

Found near ponds, streams, wetlands, and wooded areas; adults often wander onto vegetation, buildings, or window screens.

Diet & Feeding

A generalist predator that eats insects, other spiders, and occasionally small aquatic organisms or tiny vertebrates. It captures prey by ambush rather than building a typical prey-catching web.

Behavior Patterns

Primarily nocturnal and fast-moving; it can run across water and detect surface vibrations. Females carry a large egg sac with their jaws and guard the spiderlings after hatching.

Risks & Benefits

Generally harmless to humans, though it may bite if trapped or handled; bites are uncommon and usually cause localized pain and swelling. It benefits gardens and homes by consuming mosquitoes, flies, and other arthropods.