107 



It is very noticeable that the dried squares which were picked from 

 the plants produced by far the largest part of all the parasites obtained, 

 342 squares giving 50 parasites. In this lot, therefore, 14 per cent of 

 the total number contained parasites of some kind and 13 per cent 

 were undoubtedly developed from the weevil larvae. Taking all other 

 squares together, 5,286 yielded only 18 primary parasites, or only 0.3 

 per cent. 



Previous efforts to breed parasites of the weevil yielded as meager 

 results as those which have just been recorded, though they add to 

 the number of species. In 1894 Prof. C. H. T. Townseud bred, at 

 Corpus Christi, Tex., a single specimen of Urosigalplius robustus 

 Ashm., which was in all probability a primary parasite, as was also 

 Bracon dorsata Say, of which 

 Mr. Schwarz obtained two 

 specimens at Goliad, Tex. , in 

 the fall of 1895. A specimen 

 of Eurytoma tylodermatis 

 Ashm., also reared by Mr. 

 Townsend, may possibly have 

 had some other host. 



Pediculo ides ventricosus 

 IsTewp. — This small mite has 

 been thought by some scien- 

 tists to be the most promising- 

 parasite yet found attacking 

 the weevil. It has been ex- 

 perimented with quite exten- 

 sively by Prof. A. L. Herrera 

 and his assistants of the Mexi- 

 can Commission of Parasi- 

 tology. The mites breed with 

 extreme rapidity, the larvae of 

 wasps being their usual hosts. 

 Both sexes attain full physical 



and sexual maturity while yet within the body of the mother. The 

 males are exceedingly tiny, as are also the females, when they first 

 leave the mother mite. As the females become gravid, however, their 

 abdomens swell to an astonishing size as compared with the rest of 

 the body, being distended by the rapid growth of the young mites 

 (fig. 5). When these are born the mother dies, while the offspring 

 mate, and then immediately begin the search for food. The idea of 

 the Mexican investigators was that these tiny 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 pupae 

 within. Upon his return from a trip to Mexico in the fall of 1902, 

 the senior author brought with him, through the kindness of Pro- 



Fig.5.— Enemy of cotton boll weevil, Pediculoides ven- 

 ty-icosus—much. enlarged (adapted from Brucker). 



