378 The University Science Bulletin. 



grain in the horse collars. Where the grain was most abundant 1 

 found the largest percentage of larvae. In wandering in search of 

 food many holes were made through the straw, upon which they fed 

 in the meantime ; and upon coming in contact with the inner surface 

 of the leather, holes about the size of a pinhead were made, through 

 which they emerged, thus injuring the salability and market value 

 of the leather goods. I placed a number of the specimens, soon 

 after they were hatched, on a leather diet, and I found they did not 

 eat at all. 



Mr. J. E. Wodsedalek (1912) says with reference to the species 

 Trogoderma tarsale: 



"A number of the specimens were placed on a feather diet, and although 

 they are now two years old, they have grown but veiy little. When they were 

 one year old they were veiy little larger than the newly hatched individuals, 

 and at the end of the second year of life they reached a meager size equal to 

 that which specimens fed on insects ordinarily attain in two weeks. Their de- 

 velopment on wool is even slower." 



F. H. Chittenden (1897) states: 



"One jar of flaxseed from the museum department is infested chiefly by this 

 common museum pest. Many of the larvae may be seen through the glass, and 

 large patches of their yellowish-brown gnawings and excrement show whene 

 they have been at work. In castor beans a few were present. 



"That this species of Trogoderma can subsist on a vegetable diet is as posi- 

 tive as it is surprising. No other Coleoptera, to my knowledge, live on oil 

 seeds, and I had nearly arrived at the conclusion that this form of matter was 

 the nearest approach to animal food available, and that these insects could 

 only thrive on such vegetable substances as contain a considerable portion of 

 oleaginous matter. Judge my astonishment when a few weeks after the dis- 

 covery of the Trogoderma living in oil seeds, Doctor Howard brought me a 

 box nearly full of cayenne pepper in which were several Trogoderma larvae. 

 The most careful search failed to show even a fragment of that well-known 

 red pepper pest, Sitodrepa panicea, or of any other insect than the Derme- 

 stida?. Subsequently the adult was reared and proved to be Trogoderma tar- 

 sale. 



"To ascertain whether this species would breed on so pungent a substance 

 as cayenne pepper, a few adults were confined with a quantity of this condi- 

 ment. In due time larvae appeared, and when examined, August 20, or nearly 

 ten weeks from the time the eggs were deposited, were in vigorous condition, 

 the average individual measuring a tenth of an inch in length, or about half 

 that of the full-grown larvae. Toward the end of September, while passing 

 through the museum of this department, my attention was attracted by an 

 accumulation of powder and dust about the edges of an exhibit of peanut oil 

 cake, and another of Indian-turnip bulbs. A large number of the larvae and 

 their cast skins were found under the cakes, also in the flour and meal prepared 

 from peanuts. The Indian-turnip bulbs were very old and dry, and might have 

 been on exhibition twenty years or more. 



