4 BULLETIN 436, U. S. DEPARTMENT OF AGRICULTURE. 
Mr. R. N. Wilson, in notes made during May, 1912, at Sacaton, 
Ariz., relative to a small area cultivated by the Pima Indians, stated 
that corn on the Bureau of Plant Industry Experimental Farm at 
that place had been entirely killed by these beetles before it matured. 
Mr. Hudson, agent in charge of this farm, says that this is the usual 
fate of the early corn planted at Sacaton, but that some years the 
beetles are not so numerous and the corn partially escapes, although 
it is not so vigorous as it should be, on account of the beetle attack. 
Three years previous to this, Mr. C. N. Ainslie, also of the Bureau 
of Entomology, made the following notes on his observations in the 
same locality: 
Heard early this a. m. that a "black bug" was destroying corn in garden. Found 
several long rows of corn 4 to 6 inches high, almost killed by Chaetocnema ectypa. The 
beetles were clustered on the leaves and in many cases a dozen or more would be 
down in the center, busy with the terminal leaf. The hills looked as if blasted by a 
hot wind. 
Some volunteer stalks of corn 2 feet high, in a watermelon patch some rods away, 
were bleached almost white, as was a plat of corn 2 feet high on experimental plat, 60 
rods or so distant. These beetles are credited with doing much mischief to corn here. 
Dr. A. W. Morrill x states: 
The corn flea-beetle, Chaetocnema ectypa, was unusually abundant in parts of the 
Salt River Valley, and was especially troublesome in experimental plots of Sudan 
grass at the experiment station farm near Phoenix. 
Prof. G. F. Freeman, 2 of the University of Arizona Experiment 
Station, in speaking of variety tests of Papago and other varieties of 
sweet corn, says: 
Small black flea-beetles (Chaetocnema ectypa) injured both lots quite severely. So 
many plants of the early lot at Tucson were killed that all plots had to be replanted 
about April 20. The latter planting was injured to some extent but very few plants 
were killed outright. 
From these observations it is obvious that the injury caused by 
this beetle is such as to demand careful attention, and vigorous efforts 
should be made to reduce its numbers upon the ranches of the south- 
western United States. 
FOOD PLANTS. 
It seems probable that this beetle had as its native food plant some 
one or more of the native grasses growing in the Southwestern States, 
as it is found on quite a number of these. It is especially abundant 
at different times on wild barley (Hordeum murinum), salt grass 
(DisticTilis spicata), Johnson grass (Sorghum Jtalepense), and hair- 
grass dropseed (Sporobolus airoides), as well as on others. Johnson 
grass and salt grass are two of its favorite food plants, and at all 
1 Morrill, A. W. Report of the entomologist of the Arizona Commission of Agriculture and Horticulture. 
In 6th Ann. Rpt. Ariz. Com. Agr. Hort., p. 33. 1914. 
3 Freeman, G. F. Papago sweet corn, a new variety. Ariz. Agr. Exp. Sta. Bui. 75, p. 462. May, 1915. 
