ENTOMOLOGY 



C. T. VORHIES 



During the fiscal year 1920-1921, the investigation work 

 of the life history of the banner-tailed kangaroo rat (Dipo- 

 domys spectabilis) has been completed. This work has been 

 carried as an Adams fund project. The life-history phase of 

 the investigation has been written up in co-authorship with Dr. 

 Walter P. Taylor of the United States Biological Survey and 

 will shortly appear as a joint publication of this Station and 

 the Bureau of Biological Survey, United States Department of 

 Agriculture. 



WORK ON ARIZONA PINK BOLLWORM 



In August, 1920, a new Adams fund project was inaugu- 

 rated. This is an investigation of a native insect which exists 

 on the Arizona wild cotton (Thurberia thespesioides) . In its 

 larval or grub stage this pest lives in and eats out the bolls of the 

 wild cotton to the number of several bolls for each larva. It 

 is, therefore, in fact a native bollworm, more destructive to 

 its normal host than the Arizona boll weevil. It has been 

 called the "Arizona pink bollworm" and may continue to be so 

 called, since it is distinctly pink in color. It should be kept 

 clearly in mind, however, that this is neither the ordinary boll- 

 worm nor the corn ear-worm, already infesting cultivated cot- 

 ton in Arizona; nor is it the same as the Egyptian pink boll- 

 worm, which dreaded pest does not yet occur in this State. 

 These two pink bollworms belong, in fact, to different families 

 of moths. The insect now under consideration does not occur 

 as yet on cultivated cotton anywhere, but must be recog- 

 nized as a potentially dangerous insect. The investigation 

 now under way is designed to determine whether the Arizona 

 pink bollworm is adaptable to cultivated cotton, and also 

 whether it is likely to become a dangerous pest of that crop. 

 We have already proved that this insect can live its entire lar- 

 val life in the bolls of Pima cotton. 



WHEAT INJURY DUE TO HYLEMYIA CILICRURA 



In December, 1920, samples of seed wheat, which had al- 

 most wholly failed to germinate in certain fields, were brought 

 in by Mr. F. L. Ginter of Safford, Arizona. The grains, recov- 

 ered from the soil of the affected fields, were found to be in- 

 fested and eaten out by numerous small fly larvae. From these 



