118 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



A NOTE ON THE OCCURRENCE OF CHRYSOMYZA DEMANDATA 



FABRICIUS. 



BY C. N. AINSLIE. 



About the middle of the month of June, 1909, during a week 

 spent at Sacaton, Arizona, the agency village of the Pima 

 tribe of Indians, I had occasion to investigate, among other 

 things, a field of corn that was owned and cultivated by one 

 of these Indians. The corn raised by this tribe is a peculiar 

 dwarf variety that probably came from old Mexico many 

 years, possibly centuries, ago. The particular field that I 

 visited lay not far from the dry bed of the Gila River, and 

 was badly overgrown with wild sunflowers and other weeds. 

 It was also infested to a remarkable extent by Heliothis obso- 

 Icta, being by far the worst field, in this respect, that ever 

 came under my observation. Every ear and nubbin appeared 

 to be tenanted by from one to four or five of these repulsive 

 larvae, while the tassels, stalks, and even the suckers were, or 

 had been, the home of multitudes more. 



While examining some of these suckers that were in a de- 

 cayed condition owing to the galleries having been filled with 

 the abundant excrement voided by the Heliothis larvae, I 

 found a number of dipterous larvae and pupae inhabiting this 

 clamp and disagreeable situation. A few of these were col- 

 lected and reared, the adults that emerged being subsequently 

 determined by Mr. D. W. Coquillet as Chrysomyza deman- 

 data Fabr. 



Mr. M. French Oilman, at that time in temporary charge 

 of the experiment work on the agency farm and since then 

 promoted to the post of assistant superintendent of the Pima 

 Agency, a keen observer to whom I was indebted for many 

 courtesies during my visit, told me he was sure he had seen 

 the same dipterous larvae in the stems of dead date palms on 

 the farm. Repairing to the nursery where numerous small 

 date palms a foot or more in height were growing, we had no 

 difficulty in finding many full-grown dipterous larvae in the 

 heart of the dead stems and between the decaying leaves. A 

 few of the palm plants were alive with the larvae, dozens of 

 them wriggling out when the stems were split. These larva 

 were so nearly mature that when placed in a vial for rearing 

 they promptly pupated. Confinement was too much for most 

 of them, but enough of them survived to make it reasonably 

 certain that this was the same species I had found in the de- 

 caying- cornstalks. The palm nursery had been recently 

 irrigated and the pith in the dead plants was saturated with 



