EXPERIMENTS AGAINST CARPET BEETLES. 29 



13. Borax, salt, and sulphur did not kill clothes-moth eggs; 50 

 per cent and 70 per cent solutions of ethyl alcohol and a 16 per cent 

 solution of formaldehyde killed the eggs. 



14. Fumigation with sulphur proved effective in killing both adults 

 and larvse. 



15. Heat killed both larvae and eggs when they were exposed in 

 an oven for 31 minutes at 110° F., and in less time at higher tempera- 

 tures. 



16. Hot water killed both larvae and eggs when infested flannel 

 was dipped for 10 seconds in water at a temperature of 140° F. 



CARPET BEETLES. 



SPECIES USED IN EXPERIMENTS. 



There are two well-known species of carpet beetles in the United 

 States, both injurious to woolen fabrics, but, in contrast to the clothes 

 moths, generally attacking the heavier fabrics, such as carpets and 

 blankets. One species is known as the " carpet beetle " or " black 

 carpet beetle" {Attagenus piceus Oliv.) and the other as the " carpet 

 beetle" or "buffalo bug" {Anthrenus scrophulariae L.). The 

 former species, on account of its greater abundance in Washington, 

 D. C., was used in the experimental work. 



METHODS OF TESTING. 



The methods used in testing the insecticide materials against the 

 carpet beetle were essentially the same as used in the clothes-moth 

 tests described on pages 16 and 18. 



EXPERIMENTS AGAINST CARPET BEETLES. 



NAPHTHALENE. 



Effect on carpet-'beetle adults. — Two cage tests with naphthalene 

 flakes and two with naphthalene balls, 30 adult beetles being used in 

 each test, resulted in complete protection of the treated flannel in 

 all cases, while the untreated flannel was infested with from 5 to 13 

 living larvae. 



Two trunks containing flannel were used in tests against the adult 

 beetles. In one trunk naphthalene flakes were applied at the rate 

 of one-half pound to 13 cubic feet, and 40 beetles were added ; in the 

 other naphthalene balls were applied at the rate of one-half pound 

 to 10 cubic feet, and 30 beetles were added. Four weeks after treat- 

 ment all of the beetles were dead and no larvae were present in the 

 trunk treated with naphthalene flakes. No live adults, but 3 live and 

 2 dead larvae, were found in the trunk treated with naphthalene balls, 

 8 weeks after treatment, and the flannel was not damaged. In an 



