Solitary species known as spider, or spider-hunting, wasps. With their long legs they are usually seen making short rapid movements across bare ground and through short vegetation during warm, sunny weather. The female hunts for spiders as food for the larvae. See Day (1988) for details of prey. One spider is provided for each larva. The female paralyses its prey and then usually carries or drags it across the ground to a place for temporary concealment or to a previously prepared nest site. Once the prey is in a cell an egg is laid on it and often the burrow to the cell is blocked. On hatching, the larva punctures the host's body and begins to suck its internal fluids. The spider eventually dies. Over-wintering is usually as a mature larva. There may be one or several generations a year. Nationally: 15 genera with 44 species (2 species restricted to the Channel Islands). Nine of the genera have been selected for further comment.