194 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



and offensive in Arizona as it is in the average state. In the section 

 of the state where typhoid fever is most prevalent, there is rather 

 strong evidence that this insect and not the water supply is largely 

 responsible for the spread of the disease. The same insect is no doubt 

 an important agent in the spread of trachoma, an eye disease which 

 is particularly prevalent among the Indians. 



The alfalfa gall midge {Asphondylia miki) originally described 

 from Europe and reported by Professor Webster^ during the past 

 year as occurring in Salt River Valley and vicinity has thus far proven 

 of but little economic importance in Arizona. Characteristic galled 

 seed pods were discovered in the northeastern part of the state at 

 St. Johns in September, 1911, and in September, 1912, at Holbrook. 

 Both. of these occurrences are so isolated as to almost preclude the 

 possibility of artificial introduction. At Holbrook there is no farming 

 done and the infested pods were on a few volunteer alfalfa plants. 

 It seems safe to predict that a wild food plant will eventually be found 

 in Arizona. 



Hymenoytera. In this order Arizona has three pests of high 

 rank in the clover seed chalcis (Bruchophagus funebris) , the harvester 

 ant (Pogonomyrmex harhata vars) and leaf cutter bees, of possibly 

 more than one species. The clover seed chalcis not only causes a 

 direct loss to alfalfa seed growers in Arizona of more than $100,000 

 per year, but dissipates the hopes for the development of the seed 

 producing industry which the state is peculiarly suited for climatically, 

 until some satisfactory method of avoiding the injury is worked out. 

 The past year was marked by a still further decline in alfalfa seed 

 production in the Buckeye Valley, which as a new district became 

 noted for its alfalfa seed several years ago. 



The harvester ants are responsible for the large and numerous bare 

 spots which are found in the alfalfa grain fields, particularly in 

 the Salt River Valley ' In this connection a use for London Purple 

 not generally known to entomologists should be noted. This poison 

 owing to its fine state of pulverization seems especially adapted for 

 placing around the entrance of the nests of the ants where it may 

 adhere to the feet of the insects and be carried into the nests to poison 

 the food supply. I have been unable to obtain any early history 

 of the use of London Purple in this manner. Sometimes ineffective 

 lots may be obtained. Two years ago analyses were made of a series 

 of samples which represented, as shown by thorough field tests, various 

 degrees of effectiveness.^ It was my expectation that the analyses 

 would provide a chemical basis for selecting grades of London Purple 



1 Circular 147, Bureau of Entomology, U. S. Department of Agriculture, (1912). 



2 Twenty-first Annual Report Arizona Horticultural Experiment Station, p. 391. 



