109 



of numbers and in the time of its activity. While such parasites 

 might serve to decrease the numbers of the weevil, eveiy larva that 

 becomes parasitized has already done its damage to a square. 



In spite of the present unpromising outlook for the discovery of 

 valuable parasites of the weevil, every effort to find such should be 

 made. While earnestly hoping that effective parasites may yet be 

 discovered or developed, it is folly foi- planters to neglect or delay 

 the adoption of those methods of decreasing weevil injury which 

 have already proven to be both practical and effective. 



PREDATORY ENEMIES. 



INSECTS. 



Insects which prey upon the boll weevil appear to be even fewer in 

 number of species than are those which are parasitic upon it. The 

 principal enemies of this class are ants, 

 and where common these probably destroy 

 more immature weevils than do the para- 

 sites. They are frequently to be found 

 in squares on the ground in the act of 

 destroying larva; or more often pupae. 

 Occasionally they have been found enter- 

 ing infested bolls which are yet hanging 

 upon the plants and destroying the pupfe, 

 which had become exposed by the j)rema- 

 ture cracking oj)en of their cells. In some 

 cases they have been known to destroy 

 young adults which had emerged but not 

 become fully hardened. Several species 

 of ants are concerned in this good work. 

 The most active is a small red ant, Sole- 

 nopsis debilis var, texana Mayer? (fig, 6). 

 Another species belonging to the genus Myrmica also does considerable 

 good. 



Occasionally there may be seen upon cotton plants specimens of a 

 mantis, or "devil horse," as it is more commonly called. One species 

 only, Stagmomantis limhata Hahn., has been carefull}^ tested for its 

 ability to destroy weevils. A male of this species was confined in a 

 breeding cage and supplied with a number of adult weevils. Sev- 

 eral times it was seen to seize a weevil and attempt to eat it, but 

 being unable to break through the hard chitinous plates which so 

 closely cover the weevil's body, it gave up the attempt and let the 

 weevil go unharmed. Although kept for some time with weevils in 

 its cage, it never fed upon them, but starved to death in their pres- 

 ence. With the female of this species the case is quite diffei-ent. 

 One was confined in a cage and supplied with an abundance of wee- 



PiG. 6.—Solenopsis debilis var. tex- 

 ima'f ant enemy of boll weevil — 

 much enlarged (original). 



