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JOURNAL OF ECONOMIC ENTOMOLOGY 
(Vol. 17 
in a short time the first pair of legs would become useless. The an¬ 
tennae seemed to be the last organs which were affected. Naturally a 
few of the beetles escaped before they got enough gas to stop them, also 
a very small number of the beetles revived enough to crawl awav. 
The garden was examined the following morning. Some of the beetles 
on the ground were still able to slightly move their legs and antennae. 
A number of these were collected and brought in the laboratory .Twenty- 
four hours later they were all dead. Very few of the beetles escaped 
and the injury they did to the garden was slight. Similar results were 
obtained in every case where calcium cyanide dust was used for the 
control of blister beetles. 
A few tests were made with calcium cyanide on squash and melon 
vines for the control of the striped cucumber beetle (Diabrotica vittata 
Fab.), and the squash bug (Anasa tristis DeG.). Calcium cyanide 
flakes used at the rate of one teaspoon per hill killed both the insects 
and the plants. The granules and the dust gave the same results. 
Equal parts of calcium cyanide dust and air slacked lime used at the 
above rate showed no injury to the plants but did not give satisfactory 
control. However, from the results obtained it seems probable that it 
will be possible to work out a dosage which can be used satisfactorily 
for the control of melon pests. 
Plant lice succumb quickly to very small quantities of calcium cyanide 
dust. The dust was successfully used on melons and on Spiraea Van 
Houtti. It was applied with a small hand bellows. The aphids were 
almost instantly killed and without injury to the plants. 
Recently the Department of Horticulture of the Missouri Agricultural 
Experiment Station has been depending upon calcium cyanide dust 
for the control of the white fly (Aleurodes vaporariorum Westw.) in their 
greenhouses. The results have been entirely satisfactory. It was first 
used last May in a greenhouse containing young tomato plants which 
were badly infested with white flv. The house contained 775S cu. ft. 
of space. Eleven ounces of dust was used. It was evenly distributed 
on the beds thruout the house and some of the dust was placed directly 
on the leaves. The application was made at 6:10 P. M. May 23, 1923. 
The house was opened the next morning at 4:35. All adult flies were 
dead. Most of the larvae and eggs were killed. The pupa appeared 
to be alive. Seven days later several adults had emerged from the 
pupa and the few eggs which had not been killed were hatching. Where 
the calcium cyanide came in contact with the leaves it caused serious 
