ovipositor Specialized egg-laying organ which in most insects is formed from outgrowths of the eighth and ninth abdominal segments. There are six outgrowths in all, known as valves, and these may be modified to form a variety of structures. In some insects the valves are short and in others they are drawn out to form a long, stylet-like tube. Extreme forms of ovipositor occur in the sawflies, ichneumons, and wood wasps, where it may be longer than the entire body, and equipped apically with saw teeth to aid penetration of hard plant tissues. Worker bees and sterile female wasps have the ovipositor modified to form a stinging organ and poison sac.

ovipositor An organ at the hind end of the abdomen of female insects through which eggs are laid. It consists of a pair of modified appendages and is often long and piercing, so that eggs can be laid in otherwise inaccessible places. The sting of bees and wasps is a modified ovipositor.