110 BULLETIN 67, UNITED STATES NATIONAL MUSEUM. 



Some collectors arrange valuable specimens, such as types of new 

 species, differently from the regular collection. Mr. Ball and others 

 keep the type-specimens in separate boxes, taking care to handle 

 them as little as possible. Mr. Caudell puts up types of Orthoptera 

 in Riker mounts, but this will hardly do for insects of any other 

 order. Many entomologists send their types to some large museum. 

 Several entomologists, who have sufficient means for the purpose, 

 construct a small building of brick or stone to house their valuable 

 collections. 



PESTS IN COLLECTIONS. 



After the entomologist has collected, pinned, spread, labeled, and 

 arranged the specimens in the cabinet he is not permitted to keep 

 them in peace. Certain other insects, mites, mold, grease, etc., make 

 their appearance, and unfailing vigilance is the price of perfect 

 specimens. Neglect to attend to a collection will surely invite its 

 destruction. In some parts of the country these pests are not nearly 

 as abundant or as destructive as in other portions. The most injuri- 

 ous insect pests are beetles of the families Dermestidre, Bostrychidse, 

 Ptinidse, and Tenebrionidse. 



The larvje of the Dermestidie are hairy creatures with short legs 

 and often with tufts of hair at the ends of the body. They feed and 

 breed all the year, except when it is too cold. They will feed on a 

 great variety of substances, boring into and reducing them to a mass 

 of fine dust. The forms most injurious belong to the genera Dermestes, 

 Trogoderma, Anthrenus, Attagenus, and Perimegatoma. Anthrenus 

 verbasci (varius) is the common pest in most collections in the north- 

 eastern part of the United States. Trogoderma tarsale is more abun- 

 dant in the South and West. Anthrenus scropJiularise is occasionally 

 found in collections. Two species of Attagenus, A. peUio, and A. 

 megatoma, sometimes attack insect collections, and Dermestes lar- 

 darius is also an occasional enemy. Perimegatoma variegatum is so far 

 only found in collections in California. Recently a peculiar and 

 remarkable dermestid has been found in some collections; it is 

 Thelydrias contractus, better known as Ignotus xnigmaticus. The 

 Chilean insect pest Cryptorhopalum jlavopictum will doubtless some 

 day be introduced into our collections. Of the Ptinidse, one species, 

 Ptinus fur, is sometimes found feeding in collections, and one Tene- 

 brionid, Tribolium ferrugineum, a cosmopolitan beetle feeding on 

 many kinds of stored foods, is found but rarely, most often on im- 

 ported collections. One Bostrychid, Dinoderus pusillus, has been 

 also taken a few times in insect collections. Of the Psocidse, several 

 species of wingless forms, principally Troctes divinatorius , often do 

 much damage to pinned insects. The delicate specimens are espe- 

 cially subject to their attack. A few mites and a Tineid larva are 



