HYMENOPTERA 953 



Family TIPHIID.E 



The Tiphiids 



The tiphiids are quite closeh' related to the followinj^ family, the 

 velvet-ants. In fact, some of the genera now included in the Tiphiidag 

 have been classed in the Mutillidaj. The characters separating these 

 two families are indicated in the table of families of the H\Tnenoptera 

 given above. The family Tiphiida3 includes three subfamilies. 



The subfamily TIPHIIN^ is represented in our fauna by five 



genera; these are Pterombtis, Epotnidtopteron, Elis (Myzine), Tiphia, 



and Paratiphia. One of the most common species 



is Tiphia inorndta (Fig. 1174). This is a shining 



black species ; the male measures from 7 to 1 1 mm. 

 in length and has an upward projecting spine near 

 the tip of the abdomen. The female measures 



p. "^ T'bi ' from 12 to 14 mm. in length. The accompanying 



^morncUa. figure represents a female; in this sex the anten- 



nae are curled much more than is indicated in the 

 figure. This species is parasitic upon white-grubs, 

 the larvae of the Mav-beetles. For descriptions of species of Tiphia 

 see Malloch ('18). 



The subfamily METHOCIN^ includes forms in which the two 

 sexes are very dissimilar; the males are winged, the females are wing- 

 less and resemble ants. Our only species is Methoca stygia. 

 The subfamily MYRMOSIN^ includes two genera, Myrmdsa and 

 Myrnwsida. The males are winged and the females are wingless. 

 Our most common species is Myrmosa unicolor. The subfamily has 

 been monographed by Bradley ('17). 



Family MUTILLID^ 



The Velvet-ants 



These handsome insects resemble ants in the general form of the 

 body, but lack the scale-like knot of the pedicel of the abdomen 

 characteristic of the true ants, although there is 

 sometimes a constriction between the first and second 

 abdominal segments (Fig. 11 75). The body is often 

 densely clothed with hair, which gives the insects the 

 appearance of being clothed in velvet; and as the Fig. 1175. 



body is usually ringed or spotted with two or more 

 strongly contrasting colors, they are very conspicuous. But in many 

 species the body is naked. 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 rapidly and 

 they sting severely. In the western states there are many straw yellow 

 species, which are nocturnal. 



These insects are abundant in the warmer portions of our country, 

 and several species occur in the North. A large species, Dasymuttlla 



