105 



moldy when received. Thirteen apparently healthy pupae were 

 removed from these moldy squares with the intention of rearing the 

 adults. The pupae were kept moist, and in a short time 5 died, 

 apparently from the attacks of an unknown species of fungus. The 

 remainder were then kept dry, but in spite of this precaution 6 more 

 died, only 2 becoming adult. In another lot of 27 pupae, 5 died, 

 apparently from attacks of the same fungus. 



Specimens of the dead pupae were sent to the pathologist of the 

 Bureau of Plant Industry of the Department for determination of the 

 fungus. It was pronounced to be a probably new species of Asper- 

 gillus. As no species of this genus is known to be parasitic, it may 

 be that the pupae died from some other cause and that the fungus was 

 entirely saprophytic. The external appearance of the fungus so soon 

 after the death of the pupae, the large mortality prevailing, and the 

 known fact that pupae develop uninjured in the presence of many 

 species of molds leads to the suspicion that it may have had some 

 part in causing the death of the insects. 



In 1894 Prof. C. H. T. Townsend, while engaged in the study of 

 the boll weevil, found in a field at San Juan Allende, Mexico, a speci- 

 men of a dead pupa which had been attacked by a species of parasitic 

 fungus (Cordyceps sp.). As no other cases of attack by this fungus 

 have been reported, its occurrence is probably very rare. 



PARASITES. 



BREEDING OF PARASITES. 



Owing to the importance attached to parasites in the control of 

 many pests, considerable time has been devoted to the rearing of para- 

 sitic enemies of the boll weevil. From the very nature of the habits 

 of the weevil, no perfectly satisfactory method of breeding these para- 

 sites could be devised. The apparatus used was exceedingly simple. 

 Squares which were thought to be infested were picked or gathered 

 in the field, and cleared, so far as was possible, of all that might pro- 

 duce parasites not developed from the weevils. Small lots of these 

 squares were placed in paper bags, each fitting tightly over the open 

 mouth of a glass jar. As both parasites and weevils upon emergence 

 naturally make their way to the light, they could easily be seen in the 

 glass jars and at once removed. Even when thus bred something 

 must be known of the habits of each species of insect produced or of 

 its close allies to determine whether it is really a parasite upon a 

 weevil larva, a hyperparasite, or merely a vegetable feeder devel- 

 oped in the decaying square. Many small flies breed in such decaying 

 matter and were caught in the jars, but these must all be acquitted of 

 being parasites upon the weevil. The results are therefore made 

 somewhat uncertain because of the impossibility of isolating the 

 weevil larvae. A condensed summary of the results in breeding 

 parasites through two seasons' work is presented in Table XXVIII. 



