EXPERIMENTS AGAINST CLOTHES MOTHS. 19 



same number of adults were liberated, the flannel was badly eaten by 

 larva?, and a large number of live larva? were present. In a duplicate 

 test, in which naphthalene balls were used at about the same rate, 

 the results were identical. 



A second series of trunk tests was made, in which three trunks of 

 average size were used, and adult moths were liberated in the trunks 

 from time to time during the course of the experiments. In trunk 

 No. 1 three-fourths pound of naphthalene flakes was scattered over 

 the flannel and over the bottom of the trunk. Ten moths v^'ere added 

 every two weeks, from May 7 to July 21, making a total of 70 moths 

 used. Two months later (Sept. 20) examination developed that 

 the flannel was unhurt, and no living adults, no larvae, or eggs 

 were found. In trunk No. 2 one pound of naphthalene balls was 

 used, and moths were added as in trunk No. 1. The results were 

 the same as obtained with the flake naphthalene. In the check (un- 

 treated) trunk the flannel w^as badly eaten at the close of the ex- 

 periment, hundreds of live larvae and 7 live adults being present. 



To determine the rapidity with which adults are killed by confined 

 fumes of naphthalene, a third series of trunk tests was conducted. 

 Ten moths were placed in each of three tight trunks containing flan- 

 nel and in each case a reasonable amount of naphthalene flakes was 

 added. In from two to six days, all of the moths were dead. 



NAPHTHALENE : EFFECT ON CLOTHES-MOTH LABV^. 



Battery jars and trunks were used to test the effect of naphthalene 

 on the larvae. In the battery-jar tests jars of 216 cubic-inch content 

 were used. From 10 to 20 larvae, one-half to three-fourths grov/n, 

 were placed upon a piece of all-wool flannel in each jar, and a liberal 

 amount of naphthalene was applied to the entire piece of flannel. 

 Two lots of larvae, treated, and one lot, untreated, made up each test. 

 The forms of naphthalene so tested were (1) one test of coarse 

 flakes, (2) four tests of fine flakes, (3) one test of balls, and (1) 

 one test of cake or brick. In each test the jars remained open. At 

 the end of 7 days each of these substances Avas found to have killed 

 from 85 to 100 per cent of the larvae, and of the few remaining 

 ' alive some were inactive. The flannel, in all cases, was undamaged. 



In a second series of jar tests 10 half -grown larvae were placed on 

 flannel in each of five battery jars, Mdiich were tightly covered with 

 heavy paper. To the 5 jars naphthalene flakes were added at the 

 rate of 2, 4, 8, 20, and 40 grams, respectively, per cubic foot. At the 

 end of one week the 2 and 4 gram applications had killed 90 per cent, 

 and in every case all larvae had been killed by the heavier dosages. In 

 the untreated jars, serving as checks, only 5 per cent of the larvae 

 were dead. From observations on the effect of naphthalene on the 



