REAR-HORSES VS. COTTON-WORMS. 165 



As to their good offices in destroying cotton-moths, we quote from Mr. 

 F. M. Meekin, of Morrison's Mills, Alachua County, Florida : 



There is an insect commonly 

 called the mosquito-hawk (I 

 do not know its technical 

 name). It is long-bodied, has 

 two sets of membranous 

 wings, a large head, and a 

 long continuation of the ab- 

 dominal portion of the body. 

 There are many sizes and 

 colors. They live on insects 

 and on each other, and I have 

 frequently seen them catch 

 the moth of the cotton-cater- 

 pillar. This mosquito-hawk 



is very numerous here, of FIG. lO.-Libellnla trimaculata. 



many varieties, varying in 

 size from an inch to two and a half or three inches in length of body. I think it does 

 more to prevent the development of the cotton-caterpillar than all the rest of its 

 enemies. 



Mr. Meekin probably claims too much for these insects. Still, in view of 

 his statements and of the well-known habits of dragon -flies, there can be 

 little doubt but that they can be considered as active enemies of the 

 cotton-moth. 



In the next order, ORTHOPTERA, we find but one insect which preys 

 upon Aletia argillacea; although in parts of Texas, according to Mr. 

 Schwarz, the planters insist that the grasshoppers eat the cotton- worm ! 



THE REAR-HORSE, CAMEL-CRICKET, OR DEVIL'S RIDING-HORSE (Man- 

 tis Carolina). As useful an insect as occurs in the Southern States 

 is known by the above popular names in different localities. Its food 

 consists entirely of other insects, which it approaches stealthily and 

 seizes with its powerful spined forelegs. The amount of good which it 

 does in thus destroying noxious insects is hard to estimate. The capacity 

 of each individual can be seen from the fact that in one night a single 

 female has been known to kill and devour eleven Colorado potato beetles, 



FIG. 11. Eggs of Mantis Carolina. 



leaving only the wing-cases and parts of the legs.* The only objection 

 to them seems to be that they are not sufficiently discriminating in 

 choosing their prey, and beneficial as well as noxious insects suffer from 

 their attacks. They seem to be especially fond of one another, and after 

 sexual union the female frequently devours the male.t 



*See First Missouri Entomological Eeport, p. 169 (1869). 

 t See Packard's Guide to the Study of Insects, p. 575. 



