150 



abseryations relating to them, has been published as Bulletin No. 49 

 of the Bureau of Entomology. A more extended account, containing 

 the result of the studies thus far made, is now in process of publica- 

 tion, and will be found in a forthcoming bulletin of this Bureau. 



It should be stated that the work with this promising enemy of the 

 weevil is yet only in the experimental stage. Two criticall}^ impor- 

 tant questions which have yet to be answered are whether the keleps 

 will survive the winter climate of Texas, and, if so, whether they can 

 be obtained or propagated in sufficient numbers to serve the practical 

 purpose for which they have been introduced. 



An experience of at least one or two years will be required to deter- 

 mine what practical value this southern enemy of the weevil may have 

 under the very different conditions of growth and cultivation of cotton 

 as found in the United States. 



MAJvTIDS. 



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 liinbata Hahn., has been carefully 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. Several 

 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 presence. With the 

 female of this species the case is quite different. Several of these have 

 been confined in cages and supplied with an abundance of weevils. 

 The}' seemed to be more powerful than the males, breaking through 

 the weevil's skeleton with apparent ease. On several occasions speci- 

 mens were found to eat eight or ten weevils a day. During the period 

 of observation two of the mantids deposited Qggi^. in an average of 

 18.6 days, for 5 females of this species, they destroyed 3.4 weevils per 

 day each; no other food was provided. The total average for each 

 female was 63 weevils. As these insects become quite abundant upon 

 cotton late in the season, they doubtless succeed in destroying quite a 

 large number of weevils, but it is too late in the season for their work 

 to have any practical effect upon an abundance of the weevils. 



Some species of Mantispa are also capable of destroying weevils. 

 Though they are quite abundant in a field, the writer has seen but 

 one engaged in eating a weevil. 



BIKDS. 



There can be no doubt that birds are exceedingly valuable assistants 

 to man in reducing the numbers of many insect pests. Much has been 

 written and said as to their work in destroying the boll weevil. In 



