648 THE STUDY OF INSECTS. 



Family MUTILLID^: (Mu-til'li-dae). 

 The Velvet-ants. 



These handsome insects resemble ants in the general 

 form of the body, but lack the scale-like knot of the pedun- 

 cle of the abdomen characteristic of those insects, although 

 there is a constriction between the first and second abdomi- 

 nal segments (Fig. 769). The body is densely 

 covered with hair, which gives the insects the 

 appearance of being clothed in velvet ; and as 

 the body is usually ringed with two or more 

 strongly contrasting colors, they are very conspicuous. The 

 colors most commonly worn by the velvet-ants are black 

 and scarlet. The males are winged and frequent flowers. 

 The females are wingless ; but they run very fast, and can 

 sting severely. 



These insects are abundant in the warmer portions of 

 our country ; our lists now include one hundred and sixty 

 North American species. The largest of these and a very 

 common species is Sphcerophthalma occidentalis (Sphaer-oph- 

 thal'ma oc-ci-den-ta'lis). This species measures from two- 

 thirds of an inch to a little more than an inch in length ; it 

 varies in color, but is usually black and scarlet. It is known 

 to dig burrows in beaten paths and store in them flies and 

 other insects. It will also enter bee-hives and kill and eat 

 bees. In Texas it is known as the Cow-killer ant, because 

 of a popular superstition that its sting is very dangerous to 

 live stock. 



Several exotic species of Mutilla live in nests of bumble 

 bees; but whether they exist there as parasites or as inqui- 

 lines has not been determined. Species of Mutilla have also 

 been bred from nests of other digger-wasps, and from those 

 of certain true wasps. 



