EXPERIMENTS AGAINST CLOTHES MOTHS. 17 



were maintained, allowing 20 separate tests to be carried on at one 

 time. Each cage was made of tulip, or what is commercially known 

 as " whitewood," which, on account of its almost complete lack of 

 odor and volatile oils, should be unobjectionable to moths. The 

 inside dimensions of the cages were: Length, 3 feet; width, 2-J feet; 

 depth, 10 inches. In the top a door, 3 feet by 1^ feet, covered with 

 fine-mesh copper wire, provided means of entrance and ventilation, 

 and at the back and at one side were screened apertures as further 

 means of ventilation. 



In each cage at the beginning of a test were placed three white- 

 wood boxes, each 10 by 10 by 8 inches, fitted with sliding covers. A 

 quantity of all-wool flannel, in pieces about 6 by 12 inches, was placed 

 in each box. Flannel in two boxes was treated with the material 

 being tested, while that in the third box was untreated and served 

 as a check. The boxes containing the treated flannel were kept on 

 one side of the cage ; the untreated box on the other side, in order to 

 minimize any chance of odors from the treated flannel affecting the 

 untreated. The sliding covers were about three-fourths closed to ex- 

 clude light and, at the same time, leave ample room for entrance 

 of moths. 



Finally, from 10 to 20 adult moths were placed in the large cage, 

 the door quickly fastened, and the whole left in a quiet room. A.fter 

 a week or so more moths were often added to the cage, depending 

 upon the available supply. The cage was fairly light; boxes fairly 

 dark ; and, as moths have a decided aversion to light, this condition 

 tended to attract them to the boxes. The tests ran at least a month, 

 sometimes longer, the purpose being to secure a maximum number of 

 eggs hatched into larvas large enough to be accurately counted. At 

 the time results were recorded the number of dead moths, of living^ 

 and dead larvae, and of unhatched eggs was noted. The number of 

 live larvae found on the treated flannel, compared with the number 

 found on the untreated flannel used as a check, determined the pro- 

 tective ^ value of the substance against moth infestation. 



In addition to the cage tests, several room and trunk tests were 

 made against the adults to approach more nearlj^ practical conditions. 



Against the larvae. — The substance being tested was applied to the 

 infested flannel in trunks, boxes, open battery jars, and closed bat- 



1 The word "protective," used in connection with these tests, is a rather broad term 

 and is purposely used as such. At the time of testing the object was to determine 

 whether materials used against moths as " repellents " had any so-called " repellent " 

 effect upon the adult moth. Observations showed that, in the majority of cases where 

 the effective remedies were used, adults were found to have entered boxes containing 

 treated flannel, and often the number of dead ones there present, at the time of exami- 

 nation, equaled the number dead in boxes containing untreated flannel. It would appear, 

 then, that the substances used did not act as repellents, but that moths entered boxes 

 containing treated flannel and were either killed by the fumes or remained there until 

 death occurred from other causes. 



59108°— 18— Bull. 707 ^3 



