Leiobunum

Leiobunum is a genus of harvestmen in the family Sclerosomatidae, comprising more than one hundred described species distributed across North America, Europe, Asia and North Africa. Its members are recognized by extremely long legs, especially the second pair, which function mainly as sensory organs rather than for walking, and by pronounced differences between the sexes, with males smaller and flatter-bodied and females larger with a raised abdomen. Many species in the genus are strikingly gregarious, gathering into large clustered aggregations on tree trunks, walls and similar surfaces, a behavior that has made the genus one of the more visible and recognizable harvestman groups.