8 BULLETIN 1051, U. S. DEPARTMENT OF AGRICULTURE. 
Cedae Chests Da Not Kill One-Half to Full Grown Labv^;. 
Cedar chests can not be depended upon to kill larvae after they are 
half to full grown, or after they are about three or four months old. 
To be sure, many of these older larvae die in the chests, but it is not 
possible to tell whether their death is caused by the chests or is the 
result of the high mortality obtaining among any lot of clothes-moth 
larvae used in experimental work. The only work done indicating the 
effect of cedar chests upon the older larvae is that of Scott, Abbott, 
and Dudley (17) . They say : 
In 1915 flannel was placed in this chest, and 10 one-half to three-fourths 
grown larvae were added every two weeks until a total of 60 was reached. Ex- 
amination made two months after the last addition of larvae showed 7 live 
larvae ; 36 larvae had died and 17 had pupated. Of the 17 pupae 2 died in the 
pupa stage and 15 emerged as moths, but died before any eggs were laid. The 
flannel had been fed upon considerably, but was not badly eaten. 
Two years later (1917) this experiment was duplicated by adding 25 one-half 
to three-fourths grown larvae at one time and allowing the experiment to run 
33 days. The results were almost identical with those of the first experiment. 
On January 31, 1921, 24 well-grown larvae were placed in a chest 
upon a high-grade blue-serge cloth, and 35 others upon- a felt pillow 
top. Both lots of larvae caused serious damage to the goods by March 
2 (PL II, fig. 2). During an examination made on that date it was 
found that of the 50 larvae 18 were still in the larva stage and alive, 6 
had died, 9 had transformed to the pupa stage, and 13 had emerged 
as adults ; the remaining larvae had eaten through the cloth and es- 
caped into the clothing filling the chest. 
Of 100 larvae (40 well grown, 40 half grown, and 20 very small, 
but fully four months old) placed on January 31, 1921, in Chest 2 
in pill boxes, 13 had emerged as moths by March 2, 16 emerged be- 
tween March 2 and IT, 19 between March IT and April 30, and 12 
between April 30 and May 11 ; the remaining 40 died as larvae or 
pupae. 
Of 60 well-grown larvae placed in Chest 1 on January 31, 1921, 
2 had transformed to the adult stage by March 2, 9 became adults 
between March 2 and IT, and 14 between March IT and May 11 ; the 
remaining 35 died either as larvae or pupae. Of 50 half to full-grown 
larvae placed in Chest 3 on January 31, 13 emerged as adults by 
March 2. Of the 2, 13, and 13 adults found emerged in Chests 1, 2, 
and 3 on March 2, developing from larvae placed in chests on Janu- 
ary 31, 1921, 2, 10, and 5, respectively, were alive, while 0, 3, and 8, 
respectively, were dead. 
Half to full-grown larvae placed in Chest 2 on February 11, 1921, 
developed into adults during the period March IT to July 2T; 1, 1, 
8, 6, 4, 3, T, and 1 being found during examinations made on March 
IT, 30, April 30, May 11, June 6, July T, 15, and 2T, respectively. The 
adult found emerged during the July 2T examination, approximately 
5J months after the larvae were placed in the chest, Avas alive, very 
active, and appeared no different in general vitality from others 
emerging under normal laboratory conditions. One larva of this lot 
was found alive, normal to all appearances, and very well grown, on 
July 2T, but had died by August 3. 
Half to full-grown larvae placed in Chest 1 on February 11, 1921, 
developed into adults during the period March IT to July 23 ; 1, 8, 3, 
