18 BULLETIN 707, U. S. DEPARTMENT OE AGRICULTURE. 



tery jars. Two lots of larvae, treated, and one lot, untreated, made 

 up each test. The usual duration of each test was one week, it being 

 assumed that if the material used did not kill in that time it would 

 be of no practical value. 



Against the eggs. — Large pieces of flannel were placed in a jar 

 containing many adult moths, and when the moths had deposited 

 numerous eggs on the flannel it was taken out and cut into pieces in 

 such a manner that each piece contained 10 or more eggs. The ma- 

 terial to be tested was thoroughly applied to the pieces of flannel 

 containing the eggs, and the treated flannel was then placed in open 

 jars. An untreated lot, serving as a check, was used in each test. 

 Observations were made at the end of 10 days to 2 weeks, 



EXPERIMENTS AGAINST CLOTHES MOTHS. 



NAPHTHALENE : EFFECT ON CLOTHES-MOTH ADULTS. 



In two cage tests, as described, the flannel in the treated boxes was 

 dusted with naphthalene flakes, and 10 adult moths were liberated in 

 each cage. Examination made four weeks after treatment showed 

 that the flannel in the treated boxes was entirely free from infestation 

 by clothes-moth larvae, whereas the flannel in the untreated boxes was 

 badly infested. Two other cage teste were made, in which naph- 

 thalene in the form of cakes or "bricks" was used, with the same 

 result. 



A room approximating 1,000 cubic feet was used for a " protective 

 test " with naphthalene on a large scale. Three of the above-described 

 small whitewood boxes containing flannel were placed in opposite 

 corners of the room. About one-half pound of naphthalene flakes was 

 placed in box No. 1 ; about one-fourth pound of naphthalene flakes in 

 box No. 2 ; and one-fourth pound of naphthalene balls in box No. 6. 

 Two boxes containing untreated flannel were used as checks. One 

 hundred and forty adult moths were liberated in the room, which 

 was made sufficiently tight to prevent their escape. At the end of 

 2J months all of the treated boxes were entirely free from infestation, 

 while the untreated boxes contained many living larvae. 



A duplicate room test was made, one lot of treated flannel being 

 placed in a closet in the room, and the closet door being allowed to 

 remain open. Again, all treated flannel remained free from infesta- 

 tion, while on the untreated flannel 80 live larvse were counted. 



Several trunk tests were made. In the first series flannel, to which 

 was added naphthalene flakes at the rate of one-fourth pound to 5 

 cubic feet, was placed in a trunk of average size. Forty adult moths 

 were liberated in the trunk, and the lid closed. Examination at the 

 end of eight weeks disclosed no larvse on the flannel, and all of the 

 adults dead. In an untreated trunk serving as a check, in which the 



