EXPERIMENTS AGAINST CLOTHES MOTHS. 21 



showed that none of the eggs had hatched, while in an untreated 

 jar 16 young larvae and 2 unhatched eggs were found. 



In a duplicate test, in which naphthalene balls were placed on the 

 flannel, the results were identical. 



From the results of the foregoing experiments it will be seen that 

 naphthalene kills all stages of the clothes moth very effectively. 



CAMPHOR. 



Effect on clothes-moth adults. — Gum camphor, broken into small 

 pieces, was used at the rate of about 5 ounces to 5 cubic feet, in a 

 trunk containing flannel. Thirty moths were liberated in the trunk, 

 and the lid closed. Examination made 32 days later showed no 

 living adults and no larvae, and the flannel had not been fed upon. 

 Cage tests with this substance showed a variation in efficacy from 65 

 to 100 per cent as compared with the untreated flannel. 



Effect on larva?. — Twenty-five half -grown larvae were placed on 

 clean flannel in a trunk, and gum camphor was added at the rate of, 

 about 5 ounces to 5 cubic feet and the lid closed. Thirty-two days 

 after treatment all of the larvae were found to be dead, and the flan- 

 nel had been slightly damaged from feeding. 



Gum camphor scattered on infested flannel in an open jar killed 

 60 to 67 per cent of the larvae in about 7 days. 



Effect on eggs. — In two tests in open battery jars gum camphor 

 killed all of the eggs, when sprinkled on pieces of flannel containing 

 10 or more eggs. 



While camphor proved effective in varying degrees against the va- 

 rious stages of the clothes moth, close observations made during the 

 course of the experiments show that it is much less active than the 

 different forms of naphthalene. 



BED-CEDAR CHEST. 



Effect on clothes-moth adults. — A red-cedar chest of 10 cubic feet 

 capacity was utilized. No record of the date of manufacture of the 

 chest could be obtained. On May 6, 1915, 10 adult moths and a 

 supply of flannel were placed in the chest. Ten more moths were 

 added every two weeks until a total of 70 was reached. Two months 

 after the last moths were added examination showed that all had 

 been killed and that no eggs or larvae were present. 



Two years later (1917) 30 moths and a supply of flannel were 

 added to the same chest. Observations made nine weeks after the ex- 

 periment was started revealed no living adults, no eggs, and no 

 larvae. In a trunk, serving as a check, to which the same number 

 of adults were added at the same time, more than 50 live larvae were 

 counted on the flannel at the close of the experiment. 



