108 



fessor Herrera. a supply of the parasites, from which, others were 

 reared for experimental work in Texas. 



In the course of these experiments the possibility of the mites 

 attacking- larvae, pupae, or immature adults was tested. The obser- 

 vations made failed to show any positive ability on the part of the 

 Pediculoides to penetrate the squares, as in only two cases were mites 

 found in them and attacking the larva?. In these two cases it seems 

 entirely possible that the mites may have entered through feeding 

 punctures or some other rupture in the floral envelopes. 



Upon several occasions during the season of 1903 mites were dis- 

 tributed in badly infested cotton fields. Later examinations were 

 carefully made, but they failed to show that the parasites had gained 

 a hold or even that they had attacked the weevils in any stage. 



These mites, if, indeed, they are of the same species as those de- 

 scribed by Xewport, are widely distributed and attack, to some 

 extent, quite a large number of insects. If they really possessed the 

 ability to get at the weevil larva? and the predisposition to attack 

 them when they could get to them in preference to other hosts, they 

 should certainly have shown something of these capabilities some- 

 where within the infested area in Texas during the ten years that the 

 weevil has been found there. As no such ability has yet been shown, 

 we doubt that the Pediculoides will ever prove of any value as a par- 

 asite of the weevil in the United States, though it may be more effi- 

 cient in more southern countries. Furthermore, it is said that even 

 where the mites do become established they are so subject to the 

 attacks of small ants that their efficiency becomes largely destroyed. 



Several attempts have been made by agents of this Division to 

 breed parasites of the weevil in localities which must be much nearer 

 its original home than is Texas, but thus far these attempts have 

 proven as fruitless as have those made in Texas. It seems desirable 

 that this work should be continued so as to give a more complete 

 knowledge of all the parasites of the weevil in its native home. 



These results show how insignificant is the part which insect para- 

 sites play in the problem of controlling the boll weevil in Texas. 

 The thorough protection of all immature stages of the weevil by 

 several layers of vegetable matter and the protection of the adult by 

 its hard, closely fitting, chitinous, external plates renders very small 

 the hope that any parasite will ever become an efficient factor in 

 controlling this dangerous pest. 



There is at present, therefore, no promise of any considerable 

 assistance in the control of the weevil by any parasite now known. 

 Because of its peculiar life history the weevil is unusually exempt 

 from the attacks of parasites. Even should one be found which 

 could attack the weevil in some stage, it would probably still fail to 

 be an efficient means of control, because, from the very nature of its 

 parasitic habits, it is bound to be behind the weevil both in the point 



