Among the obvious structural differences are harvestmen’s having one apparently unified (usually egg-shaped) body, while true spiders have clearly separate head and abdomen regions. Similar species: Though they also have long, thin legs and are also often called daddy longlegs, harvestmen (in order Opiliones) are quite different and unrelated. To distinguish it from other cellar spiders may require close examination of palps, “face” structure, carapace markings, and eye groupings. Perhaps the most common species in our area is the longbodied cellar spider, Pholcus phalangioides. Many common spiders in this family have 8 eyes arranged into three groups: 2 in the center of the face, and a cluster of 3 on each side of the central pair. Most have oval or rounded abdomens, sometimes described as “peanut shaped.” Females build nonadhesive, unorganized, messy-looking cobwebs, usually in corners or crevices. Some species have darkened joints on their legs, giving them a “knobby-kneed” look. This movement turns them into a blur, rendering them practically invisible to potential predators. Other characteristics add to their camouflage: Their gray, tan, or whitish color, small body size, and remarkable habit of “vibrating” or bouncing rapidly in their webs when alarmed. The tarsi (“feet”) are flexible, adding to the wispy impression they give.

Cellar spiders are inconspicuous, harmless, fragile spiders with extremely long, thin legs.

Cellar spider with long body