552 REPORT OF NATIONAL MUSEUM, 1887. 



the odor of naphthaline. Throughout the summer, when under ordinary circumstances 

 they would have developed, the egg3 remained dormant, but after the naphthaline had 

 evaporated completely, development began. I might add here that Trogoderma is an 

 exceedingly rare pest in New York, and not common in Washington ; farther south it 

 seems to replace Anthrenus. For all these pests bisulphide of carbon is a sovereign 

 remedy, except when they are burrowing in large Coleoptera or Lepidoptera. I have 

 repeatedly soaked large Bombycids with chloroform or bisulphide, and a week later 

 found them still infested. I worked for a month over some large Lucanids (Procule- 

 jus), and finally separated the parts so that I could fill the body cavity with chloro- 

 form. In one case, that was somewhat exposed and contained old material of little 

 value, I found a specimen destroyed by Microgaster, a rare parasite for Anthrenus. 

 How they got at this box is difficult to explain, since it was tight enough to prevent 

 the entrance of the insect. 



I have noticed also that boxes on the lower tier of shelves are much more liable to 

 attack than those on upper tiers, and this leads me to believe that the parent beetle 

 will deposit eggs outside of the boxes or on the floor of the cases, and the young larva) 

 will work their way into the smallest crevices. It seems difficult to account for iso- 

 lated larva3 in boxes containing only old insects. 



Finally I find the danger of infection comparatively greater at Washington than 

 in New York, principally because the warm season begins earlier and lasts longer, in- 

 creasing the chances of infection. I find, too, that the only real chance of safety con- 

 sists in constant examination, tight boxes, and a free use of chloroform or bisulphide 

 of carbon. 



As to naphthaline, I consider that it is a good general preventive. I know that 

 it keeps out Psocids and ants. It enhances the tendency to grease and to verdigris, 

 and in tight boxes it seems to exercise a relaxing tendency, causing the wings to 

 droop. 



There are several classes of substances to be poisoned, in which the 

 colors, fabric, or character of material, and therefore the kind of poison 

 and the strength of solution, are important factors. For instance, goods 

 not fast dyed (especially cotton), or which are dyed with colors that 

 contain solutions, will start ; also fabrics or substances which may be 

 corroded or hardened, or otherwise injured, as feathers, fur, dressed 

 deer-skin, etc. Too strong a solution may also cause a deposit on fur, 

 etc., with a dulling effect. As a test for this, a black feather should be 

 dipped in the solution, if it is of corrosive sublimate or arsenic in alcohol. 

 If the solution be too strong, it will produce a white coating when dry. 

 Any solution should exert its action in two ways, first to repel the adult 

 insect, and second, to destroy the hatched larva. Pungent odors are 

 noxious to moths and the higher orders of insects, but this is hardly 

 true in the case of the beetles to which we have before alluded. The 

 pungency of odor can not be made to last long, so that the poisoning 

 quality is of prime importance. The substances used for solutions are 

 deadly poisons, and no one who has not had experience in handling 

 them had better undertake to apply them. Corrosive sublimate will 

 attack the finger-nails and the skin. It is also volatile. Arsenic is 

 prejudicial to the health; the dust, it is said, produces catarrh, both 

 gastric and nasal, though this has not been confirmed by my observa- 

 tion. 



Before poisoning, all objects should be treated with benzine, by put- 



