ORDER HYMENOPTERA. 



173 



Family Sapygidse. In these sand-wasps there is no constriction be- 

 tween the tirfet and second segments of the abdomen; the hind legs 

 are short, and the eyes indented. The species enter the burrows of 

 Osmia and other bees, depositing their eggs in the cells of their 

 hosts. Sapyqa martinii Smith. 



Family Pompilidee. The body of these often very large sand- wasps 

 is oblong and more or less compressed; the antennae are not elbowed, 

 and the hind legs are long, reaching beyond the end of the abdomen, 

 while the eyes are not indented. These active, black wasps store 



FIG. 223. Pompilus formosus, the Tarantula-killer. Natural size. 



their burrows, made in the sand, with spiders. One of the largest 

 species is Pompiltis formosus Say. 



Family Sphecidse. Very rapacious wasps with a pedicelled ab- 

 domen, the petiole slender, cylindrical, smooth; flagellum slender at 

 the end; middle tibiae with two apical spurs. They rapidly dig in 

 gravel-paths and sand-banks, provisioning their nests w r ith cater- 

 pillars, grasshoppers, or spiders, which they sting between the joints 

 of their body, paralyzing them so that they live on until their own 

 larvae hatch and eat them. Sphex ichneumonea Linn, fills its burrow 

 with grasshoppers. The species of Pelopoeus are called "mud- 

 daubers," as they build their cells of dabs of mud on the walls of 

 houses, etc. 



Family Ampulicidse. -Prothorax long and narrow, ending in front 

 in a neck; metathorax long, truncated behind; clypeus keeled, 

 beak-like. RJtinopsis cunnliailatu Say; Ampulex sibirica Fabr. 



Family Larridae. Wasps of this group have the mandibles notched 

 on the outside near the base; the labrum is concealed; the abdomen 

 is oval conical. They burrow in sand-banks, provisioning their 



