RED CEDAR CHESTS AGAINST MOTH DAMAGE. 9 



5, and 2 being found during examinations made March 17, May 11, 

 June 6, July 7, and July 23, respectively. 



Half to full-grown larvae placed in Chest 3 on February 11, 1921, 

 developed as adults during the period March 17 to June 6 ; 1,2, 3, 2, 

 and 1 moths being found during the examinations made on March 

 17, May 12, May 31, June 6, and July 7. 



A miscellaneous lot of 100 larvae, apparently half to full grown, 

 were placed in Chest 1 on April 9, 1921. Examinations made on May 

 11, May 31, July 7, July 23, and August 3 showed that there had 

 emerged 53, 2, 7, 0, and adults, respectively. Of 100 larvae of like 

 age placed on April 9, 1921, in Chest 2, 42, 4, 2, 0, 0, and adults 

 were found emerged on April 30, May 11, June 6, July 7, July 23, 

 and August 3, respectively. 



Cedar Chests Kill Young Larvae. 



Cedar chests have a pronounced killing effect upon young clothes- 

 moth larvae. Of the larvae hatching within cedar chests from the 

 2,074 eggs recorded under the discussion of the effect of chests upon 

 the vitality of the eggs, none were found alive during examinations 

 made one month from the date the eggs were placed in the chests. 

 Exception must be made for one larva hatching from eggs laid 

 April 26-27, which were placed in Chest 3 on April 27, 1921, that 

 was found alive during examinations made on May 12, 21, and 31, 

 but which was dead by June 2. 



Practically all larvae hatching within the chests died within two 

 weeks after hatching and a surprisingly large number died within 

 two or three days of hatching. Exact data on this point are lacking 

 because to obtain them would require the chests to be opened so 

 frequently that their killing power would be weakened. Thus 

 Chest 2 had been opened more often than Chests 1, 3, and 4 just 

 previous to May 21 examination recorded in Table I, with the evi- 

 dent result that its effect upon even very young larvae was quite 

 seriously affected. Scott, Abbott, and Dudley say (17) that larvae 

 hatching in chests " died almost immediately." As their examina- 

 tion was made 23 days after the eggs were placed in the chest and 

 as their work was done during warm weather, when the egg stage 

 ranges from 4 t6 8 days, their statement should be interpreted to 

 mean that the larvae died without spinning webs or leaving signs of 

 feeding. The practical point to keep in mind is that larvae hatch- 

 ing within chests did not as a rule feed (PL IV and V) upon the 

 cloth, and when they did, the damage done (PI. Ill) would not be 

 observed by the average person. 



While the statements made concerning larvae hatching within the 

 cheste from eggs placed there can not be as exact as could be wished 

 because of variations in the length of the egg stage, the age of 

 Larvae recorded in Tables I and II is definitely known and can be 

 compared with larva accidentally introduced in clothing into chests. 

 These larva hatched in the laboratory and were placed in chests at 

 the ages indicated. In these tallies are recorded data secured from 

 each of four chests grouped according to the age of the larva- and 

 the date of examination. The numbers of the chests refer to the same 

 chest- in both tables. It will be seen that larva hatching outside the 

 chests and later introduced into the chests do not die immediately, 



