FIELD BOOK OF INSECTS. 



with them; they formerly were. The common name is 

 well given. The wingless females of these wasps, scurrying 

 about in open, especially sandy, places, look like ants 

 covered with black, yellow, or red velvet. In the South- 

 west some of the species have long, white hair. The 

 winged males can not sting; those of some species are often 

 found about flowers, others are nocturnal. The two sexes 

 of a given species usually have dissimilar markings. 

 Most of these insects are unkind guests in the nests of 

 other wasps and of bees. The old genus Mutilla (Plate 

 XC) is now divided into a number of subgenera, one 

 of which is Dasymutiila. 



PSAMMOCHARID.4E 



These are the Pompilidae of older classifications. They 

 are rather slender, long-legged, solitary wasps; usually 

 black or blue, often with orange bands. The wings are 

 usually black and kept jerking while the insect is running 

 about. They prey chiefly upon spiders, the big Pepsis 

 of the Southwest not stopping short of the "tarantula." 

 Most of our species burrow in the ground to form their 

 nests but others make cells out of mud, placing them 

 under stones, etc., while the larvae of some live in the 

 nests of other diggers. Ceropales has the last-named 

 habit; the genus may be recognized by the claws of the 

 hind tarsi being bent at a right angle. Plate XCII shows 

 Psammochares atrox. 



The Potter Wasps seem to me to exceed their immediate 

 relatives, at least the solitary ones, in interesting habits. 

 The nest of Eumenes fraternus (Plate XC) justifies the com- 

 mon name given to the group but all of the species seem to 

 use clay more or less, even when their nests are burrows 

 in the pith of plant-stems. This is an extensive family 

 and, from an economic standpoint, of great importance 

 to our farmers and fruit-growers, very few of whom know 

 anything at all of the great benefit they are deriving every 

 year from these brightly marked wasps. Their prey is 



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