METHOD OF PRESERVING LEPIDOPTERA. 



PREPARED FOR THE SMITHSONIAN INSTITUTION BY TITIAN R. PEALE. 



The difficulties in the preservation of zoological collections generally arise 

 from two causes, namely, moisture and destructive insects. 



To guard against the effects of moisture requires so little ingenuity that I 

 shall merely allude incidentally to the necessity of drying the specimens well 

 at iirst, and then keeping them in dry places. 



The greatest of all difficulties to guard against, particularly in this country, 

 is the voracity of the destructive insects belonging to the entomological families 

 of Dcr))iestid(B and TlneidcB. These are the worst enemies of the zoological 

 curator, as well as the fur-trader and careful housewife. 



Tinea tapetzella, the clothes moth, which troubles the housewife and the 

 clothier, does not disturb the entomologist ; consequently the whole of this 

 family may here be passed by in silence. 



Dermestes lardarius (the bacon beetle) and Anthrenus musceorum (museum 

 beetle) and their congeners are the great depredators. In the time of the 

 Pharaohs of Egypt they destroyed the mummies which were intended to last 

 through all time, and now in our day they destroy the specimens with which 

 we hope to enlighten posterity. As they have been known for centuries, nu- 

 merous poisons and various devices have been resorted to in order to destroy 

 them, but they remain as numerous as ever, being naturalized and abundantly 

 propagated wherever man has made his resting-place on the earth. 



In early life I was a devoted student of nature, an industrious collector of 

 specimens, and a somewhat expert taxidermist. It is, however, needless to 

 record the fact that I lost my specimens, like others, almost as fast as they 

 were collected, and, as a last resource, I was compelled to undertake a careful 

 study of the habits of the enemieis with which I had to contend, in order to learn 

 the means of subduing them. I eaidy found that substances containing albu- 

 men or gelatine stand but little chance of escaping the ravages of the Dcnncs- 

 tidce, and must bo destroyed, sooner or later, by their attacks, whether moist or 

 dry, imless chemically changed in character, or kept by some mechanical ar- 

 rangement beyond the reach of the insect. I say chemically altered, because, 

 as in the case of gelatine soaked in corrosive sublimate, the coagulation of 

 the material, which is a chemical change, so alters the matter as to render 

 it no longer a proper food for the insect. The means of protecting, therefore, 

 must be adapted to the kind of specimens to be preserved. Our present object 

 is principally to describe a successful experiment in preserving Licpidoptera, and 

 to this subject we shall chiefly confine our remarks. 



The vapor of camphor, and the essential oils generally, are sickening or fatal 

 to the perfect insects of the family Dcrincstidce, but have little or no eflect upon 

 their eggs or larva) ; consequently, although these perfumes in close cases are 

 useful to keep out the parent insects, they will not destroy the progeny after a 

 lodo-ement has once been attained. The several species of this family, unlike 

 most other insects, have no fixed period or season for depositing their eggs, and 

 consequently require to be vigilantly guarded against at all times. They are 

 about one year in attaining their full growth, in which time they cast their skins 

 four or five times. Their feet, though armed with claws, are unfit to climb on 

 a hard smooth substance like that of clean polished glass. They spin no silk, 

 and therefore cannot, like many caterpillars, construct a fibrous ladder to climb 



