The Bolas Spider's abdomen helps it lure prey into its delicate, hanging lines of silk, each strand tipped with a weighty ball.
The Bolas Spider is not a web spinner. Instead, it casts lines of silk strands with a heavy globule at the end called a bola. It swings the bola when prey is within range. This species ensnares moths that fly too closely to it. It is believed to be able to produce a chemical from its abdominal protuberances that mimics the pheromone, or smell, of female moths. When male moths come seeking to mate, they are caught by the lines of silk.
Bolas Spiders are brown with an irregularly shaped abdomen. Two bumps on it look more like deformed outgrowths. A whitish marbling over the abdomen looks like a chalky residue. Males remain quite small, but females molt multiple times, growing to be 5 or 6 times larger than males. Fertilized eggs are laid in a hard, round sac and spiderlings hatch in June.
The Bolas Spider can be found in a variety of habitats ranging from gardens and meadows to shrubby areas and woodlands. They are more common in southeastern North America but have been seen westward all the way to the southern parts of California.
Scientific Name: Mastophora cornigera
Size (Adult; Length): 2mm to 15mm (0.08in to 0.59in)
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.
Pedipalps: Small appendages near the mouth used as taste and smell organs.
Cephalothorax: Contains eyes, head, mouthparts, and legs.
Abdomen: Contains various organs related to digestion, reproduction, and web-making.
Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.
NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).