30 BULLETIN 707, U. S. DEPARTMENT OF AGRICULTURE. 



untreated trunk there were several live larvae, and the flannel was 

 slightly damaged at the close of the experiment. 



In 5 closed battery- jar tests, in which the adults were tightly con- 

 fined with a small amount of naphthalene, they were killed in from 2 

 to 5 days. 



Effect on larvce. — Coarse naphthalene flakes, fine naphthalene 

 flakes, and finely powdered naphthalene, dusted on larvae infesting 

 flannel, killed 90 to 95 per cent in open- jar tests. 



In a closed trunk naphthalene flakes sprinkled on the bottom, at 

 the rate of one-half pound to 13 cubic feet, killed, in 32 days, all of 

 25 larvae placed on flannel in a lantern globe, the two ends of which 

 were covered with cheesecloth to prevent the larvae from coming in 

 direct contact with the naphthalene. The flannel had not been notice- 

 ably injured. Naphthalene balls used against larvae in the same man- 

 ner, at the rate of one-half pound to 10 cubic feet, gave the same re- 

 sults. The check trunk showed 8 per cent of the larvae dead and the 

 flannel badly eaten. 



These results indicate, as in the case of clothes moths, that the kill- 

 ing effect of naphthalene is due principally to the fumes liberated. 



Effect on eggs. — In two open battery- jar tests with naphthalene 

 flakes, applied to small pieces of flannel containing 10 or more eggs 

 each, no eggs were found to have hatched at the end of 11 days. An 

 average of 13 live larvae was found on the untreated pieces of flannel. 



In two similar tests, in which naphthalene balls were used, the re- 

 sults were identical. 



Naphthalene was found to be very effective in protecting flannel 

 from infestation by carpet beetles and in killing adults, larvae, and 

 eggs. 



CAMPHOR. 



Effect upon carpet-beetle adults. — In a cage test with gum camphor, 

 in which 35 adults were used, no larvae were found upon the treated 

 flannel at the end of about one month, while 22 live larvae were found 

 upon the untreated flannel. In a duplicate test, in which 30 adults 

 were used, 1 live and 2 dead larvae were found at the end of 30 days. 



Thirty adult beetles confined in a tight trunk containing one-half 

 pound of camphor to 9 cubic feet were dead at the end of 30 days, and 

 no larvae were found to be present. In an untreated trunk 10 live 

 larvae were found at the end of 30 days, and the flannel had been 

 slightly eaten. 



Five closed battery- jar tests, in each of which 5 to 10 beetles were 

 tightly confined with flannel treated with a small amount of camphor, 

 resulted in the killing of 80 to 100 per cent in from 4 to 7 clays. 



