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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
tured while several others escaped. Examination of the blister-beetle under the 
binoculars showed that the soft connective tissue between the metathorax and the first 
abdominal segment, dor sally, had apparently been eaten away leaving a ragged edge. 
It also appeared as if the predators had been feeding on the internal tissue surrounding 
this opening. In all other respects the blister-beetle appeared to be normal. Whether 
or not it had been previously injured could not be determined. 
L. G. Gentner, Mich. Agr . Coll. 
Diabrotica soror Leconte in Colorado. —-Miss Le Norma Veque has handed me 
a spotted beetle recently found about her house in Boulder, Colorado, and it proves 
to be D. soror , the species so common in California. I have Californian specimens 
from Berkeley and Stanford University. It seems probable that the insect is at 
least temporarily established in Boulder, as Miss Lc Veque found another in her gar¬ 
den last summer. In New Mexico wt get D. 12 -punctata , not soror. 
T. D. A. Cockerell 
Possibilities of Granular Calcium Cyanide as a Control Measure for Wireworms. 
Severe infestations of wireworms occurred during May and June, 1923, in fields of 
early cabbage near Philadelphia. Losses varied from 15% to 49% of the entire stand. 
In some fields as many as 25 individuals were taken from the roots of a single plant. 
Neither poison bran bait nor corrosive sublimate solution, 1-1000, resulted in control. 
Wireworms were confined in pots of moist soil one, two, three, and four inches 
below the surface. Five individuals were used in each experiment. Five grams of 
granular calcium cyanide were placed on the surface of the soil in each pot. When 
examined after a 48-hour period, one hundred percent kill was found to have been 
obtained in each of the treated pots while all individuals in the checks were living. 
The same treatment was then applied in one section of a heavily infested field of 
cabbage. Six to eight grams of granular calcium cyanide were placed three inches 
from each plant in a furrow left by cultivation. In some rows, dirt was thrown 
over the cyanide with a wheel hoe, in other rows the material was left exposed. 
Within twenty-four hours, the field was watered by an overhead system of irrigation. 
Five days after application, the plants were examined and an average of 81% kill was 
found to have been obtained. Twenty dead wireworms and one live individual 
were taken from one root. No difference in kill was found between the rows in 
which the material was covered and those in which it was left uncovered. A strong 
odor of cyanide was distinguishable in the soil five days after treatment. Some 
injury to the plants resulted from this treatment which may have been due to weak¬ 
ened root systems. Tests to determine the tolerance of plants to various dosages 
were repeated four times on plants which had been transplanted two weeks and 
which were not infested with wireworms. No injury resulted from dosages of 5 
grams to 10 grams per plant. Plants, treated with 12, 14, and 16 grams respectively, 
were killed. J. L. Horsfall, 
Pa. St a. Col. Laboratory , Bustleton, Pa. 
