HYMENOPTERA 



261 



holes in the ground or in wood, in which their nests are made. 

 They are distinguished from the true wasps ( J ^espind) by the wings 

 lying flat on the body when at rest. They are solitary forms, each 

 female making her own nest in which the eggs are laid, and pro- 

 visioning it with spiders, caterpillars, or other insects, upon which 

 the larvae feed. The food is stored alive in a remarkable manner. 

 The female seizes the spider or insect and stings it in the nerve 

 ganglia of the thorax, thus paralyzing it so that it remains alive 

 but helpless. The prey thus para- 

 lyzed is placed in the burrow, the 

 egg is laid with it, and the tube is 

 then sealed up, several compart- 

 ments usually being made, one after 

 another. \Yhen the egg hatches, 

 the vounsr larva finds an abundant 



J o 



supply of well-preserved food for 

 its nourishment. Many of the nests 

 are made in burrows in sandy banks, 

 others in the pith of plants, such as 

 the sumac and elder, while others 

 make mud nests or tubes, as do the 

 common mud daubers. 



Velvet-ants (Mutillidae). In the 

 warmer parts of the country one 

 will often see large, antlike insects 

 thicklv covered with black, red, or 



J 



yellow hair, which has given them 



this name. The males are winged, 



but the females are wingless and can sting severely. One of the 



largest species is bright scarlet and black, two thirds of an inch 



long, and provisions its burrows, made in beaten paths, with flies 



and other insects, though it is known to enter beehives and 



kill bees. 



The spider-wasps (Psammocharidae) are slender, long-legged, 

 blackish wasps with reddish or black wings, the body often marked 

 with red or orange ; they provision their nests with spiders. They 

 are mostly medium-sized wasps, though the tarantula hawk (Pepsis 

 formosa), which preys upon the tarantulas of the southwest, is 



Fi<;. 415. A velvet-ant (Sphaero- 



phthalnia siniilima], female. (Four 



times natural size) 



(After Lugger) 



