256 



"Injurious Occurrence of an Exotic Dermestid in the United 

 States" (IT. S. Bur. Ent., Bui. n. s. No. 38, pp. 96-97), notes 

 several attacks by this insect on silk cocoons, reel silk, and 

 leather in the vicinity of New York. The dried infested silk- 

 worm cocoons had been imported from Shanghai, China. 



The only other reference that I have located is by W. W. 

 Froggatt, "Insects Infesting Woolen Tops" (Agr. Gaz. N. S. 

 Wales, 23, p. 900, 1912). The author states that a consig-n- 

 ment of woolen tops was found to be damaged by the cosmo- 

 politan skin weevil (Dermestes cadaverinus). 



A number of the very young larvae of this species were 

 found on the drjdng roaches September 13, 1915; these were 

 placed in separate Syracuse watch-glasses and fed upon the 

 remains of the damaged roaches. The development was very 

 rapid, with this abundant food supply, and the early instars 

 lasted only two or three days. As shown in the following 

 table, the larval period consists of seven instars, and varies 

 from twenty-eight to forty-one days ; the pupal instar was very 

 constant — nine days. 



LARVAL AND PUPAL INSTAKS. 



Since the literature gives the larval period of other Der- 

 mestids as lasting from five to forty or more months, it is 

 interesting to note the rapid development of this species under 

 sub-tropical conditions. 



The larvae of this species were never observed to eat their 

 own skins and they do not destroy one another. Both larvae 

 and beetles have the habit of feigning death when first dis- 

 turbed. 



Sharp (Cambridge Natural History, Vol. VI, p. 241, 

 1909), states that Dermestids pupate in the larval skin, but 

 the species here studied invariably shed the last larval skin 

 and showed the typical pupal characters of beetles. 



