147 



these are born the mother dies, while the offspring maie and then 

 immediately begin the search for food. The idea of the Mexican 

 investigators was that these tin}^ parasites would be able to enter the 

 square through microscopic orifices in the outer layers, and that they 

 would attack and destroy the weevil larvae and pupte within. Upon 

 his return from a trip to Mexico in the fall of 1902, the senior author 

 brought with him, through the kindness of Professor Herrera, a 

 supply of the parasites, from which others were reared for experi- 

 mental work in Texas. 



In the course of these experiments the possibility of the mites 

 attacking larvae, pupse, 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 larvae. In these two cases it seems 

 entire!}^ 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 badl}^ 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 niites, if, indeed, they are of the same species as those de- 

 scribed by Newport, 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 larvae and the predisposition to attack them when 

 the}^ could get to them in preference to other hosts, they should cer- 

 tainly have shown something of these capabilities somewhere within 

 the infested area in Texas during the ten 3^ears 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 parasite of the 

 weevil in the United States, though it may be more efficient 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 Bureau 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 sev- 

 eral layers of vegetable matter and the protection of the adult by its 

 hard, closely fitting, chitinous, external plates render very small the 



