23 [ 443 ] 



The opiuious lieretofore eutertaiued respecting the habits of the Tro- 

 gositJE and their larviB have been chiefly founded upon the history of the 

 foreign species abo^'e mentioned, the Trogosita mauritanica, of Linnaeus, 

 subsequently named T. carahoides by Fabricius. These insects are often 

 found in great numbers in stored grain in the south of Europe, where 

 the larva has received the popular name of the CadeUe ; and one of the 

 older French authors, M. Olivier, speaks of its doing more damage to 

 housed grain in the southern provinces of France than any other of the 

 destructive gTain insects. The carnivorous habits of the perfect insect, 

 however, had been noticed from time to time, and Mr, Curtis, after 

 speaking of the injury done to grain by the larvjie, adds : " The beetle 

 is carnivorous, and makes some amends for the mischief it had done in 

 its larva state by destroying the Tinea granella.^'' 



The observations of a recent French author, 31. Ed. Ferris, upon the 

 larva of another species of this family, lead to the conclusion that these 

 insects are carnivorous also in the larva state, and M. Lacordaire, after 

 referring to these observations, adds : " After this it is necessary to 

 rectify what I have said above concerning the grauivorous tastes of 

 the larvae of the Trogosita mauritanica. It is more than probable, as 

 M. Ferris suggests, that they do not touch the grain in which they live, 

 but that they destroy, on the contrary, the larvae of the grain beetles 

 (Calandrce) and the caterpillars of the grain moths (Tinece and Alucitce) 

 which are the actual authors of the mischief, and therefore that instead 

 of being injurious, thej" render us a real service." 



Our observations, above recorded, upon the carnivorous habits of the 

 larva? of some of our American species, go to confirm this view. 



Before leaving the Trogositpe I may mention a curious incidental prac. 

 tice — I cannot call it a habit — of these insects. In the summer of 1871 

 one of the flouring mills in this town stood unoccupied, on account of the 

 financial difficulties of the parties owning it. The miller having it in 

 charge mentioned to me that the expensive bolting cloths in the estab- 

 lishment were being seriously damaged by some small black beetles 

 which ate small holes through them, and would soon ruin them if they 

 remained stationary, and that he was obhged to start up the machinery 

 of the mill every day in order to save them. These proved, upon ex- 

 amination, to be the larger of the two species of Trogosita above named, 

 and which I understand to be the T. castanea. 



As an enemy of the codling-moth it appears, from the testimony of 

 Dr. Weed, that the Trogositue exercise a considerable efficiency in some 

 localities, but we have not at present sufficient reason to suppose that 

 they contribute much, upon the whole, to lessen the numbers of this 

 destructive fruit insect. 



