584 Thirty-second Annual Report 



"maggots" there were reared in January a number of speci- 

 mens of small Diptera (true flies) resembling very small house 

 flies. Specimens sent to Washington were determined by a 

 specialist, Dr. J. M. Aldrich, to be Hylemyia cilicrura Rdi. This 

 is an insect occasionally reported as injurious in several other 

 states, and known under various common names, but usually 

 designated as the seed-corn maggot. It has been found infest- 

 ing turnips, radishes, seed-corn, roots of beets, planted seed 

 potatoes, beans (cotyledons and young shoots), and peas, but 

 only once previously in wheat. Available data seem to indicate 

 that damage most often occurs under conditions leading to de- 

 cay of the affected plants or seeds, the infestation being sec- 

 ondary and therefore of little consequence. There is no certain 

 evidence offered that seed grains are attacked while sound. In 

 the present case, however, there seems to be no good reason to 

 suppose that the seed wheat was in other than sound condition 

 when attacked. A sample of the grain used in seeding the 

 fields affected was clean and no insect eggs or other infestation 

 could be discovered, indicating that eggs or larvae were in the 

 soil, a conclusion verified by the available reports on the life 

 history. 



WORK WITH BEES 



A record of the 1920 season with the University bees pre- 

 sents points of some interest for this report. Throughout the 

 school year 1919-1920, thus extending into the 1920 season, 

 these bees were used for instruction in bee-keeping, and partly 

 for experimental reasons were divided into two small groups 

 of hives, one on the campus, well removed from mesquite and 

 cat's-claw in quantity, the other at the University Farm in 

 the bottom land of Rillito River, where these plants are plenti- 

 ful and within easy reach of the bees. The nine colonies were 

 large and flourishing before the end of March, and began early 

 in April to store some surplus honey from a wide variety of 

 wild flowers. Slow accumulation of surplus honey continued 

 until mesquite and cat's-claw (Prosopis velutina and Acacia 

 Greggii) began to blossom, about May 15 to 20, when the flow 

 increased. Mesquite proved to be practically without nectar, 

 though blooming profusely, with the result that the flow, which 

 at this time of year is generally mixed mesquite and cat's-claw 

 was nearly pure cat's-claw and of excellent color and flavor. 

 On May 29, the first extracting cleared out all of the mixed 



