260 llEPORT 0¥ THE COMMISSIONEK OF AGRICOLTURE. 



a single female. One female wliicli was isolated with a male was ob 

 served to lay seventeen eggs before she died, and another, tweuiy-three 

 eggs ; but this, of course, cannot be taken as the full number. Before 

 hatching the eggs swell somewhat at the larger end and the forming 

 insect is plainly seen through the transparent shell. The eggs haK;h in 

 from four to seven days. 



The newly-hatched larvje are very pale, almost white in color, are 

 furnished with long hairs at birth, and are quile active. In a few hours 

 they acquire the normal brownish-gray color and bury themselves in 

 their food. They crawl with considerable rapidity, mounting smooth 

 surfaces with ease, a])parcntly excreting from the anus an adhesive 

 substance which prevents them from falling. In the breeding jars, with 

 plenty of food and a constant temperature of from GS^ to 78° F., the 

 larvcB cast their first sjfiu in from four to nine days, the great majority 

 molting at seven days. Under the same conditions the second skin was 

 cast at from four to seven days, the majority molting at six days; the 

 third skin at from three to six days, the majority molting at five days ; 

 and the fourth skin at from three to six days, the majority molting at 

 live d«ys5 the fifth skin at from five to seven days, and the sixth skin 

 at six days. There are thus seven larval stages. 



The fully-grown larva now prepares for pupation, by forming a cavity 

 in the substance it was feeding upon, or in any other suitable material 

 near by. In the cavity or cell thus formed we find the motionless larva 

 in a curved position, loosely covered with bitten-off particles of the sur- 

 rounding material. Resting for six days in this position, the last larval 

 skin is cast and tbe pupa state (PI. VI., Fig, //) assumed. Under un- 

 favorable, t. e., winter, conditions (November and December), the period 

 from hatching to the assumption of the pupa state has been as brief 

 as forty-five days, and the pupa state has lasted fourteen days. 



From our experience with other species of this family, Bermestidcc^it 

 is plain that no general statement as to the duration of the larva state 

 can be made. Under the influence of a very warm temperature, like 

 that of Saint Louis or Savannah in midsummer, and with jdenty of nour- 

 ishing food, we are convinced that it may become only a matter of two or 

 three weeks; while, on the other hand, with an insufficient supi)ly of food 

 or a lower temperature, it may be extended for several years, as we know 

 from our experience with other species of Dermestes, and with si)ecies of 

 the allied genera, AntJircnus, Trogoderma, Attageniis and Ferimegatoina.* 



The work of the larva?, both young and full-grown, In boots and shoes, 

 consists in boring round smooth channels in every direction through 

 the leather, preferring, as previously stated, the soles and heels. A fa- 

 vorite place for entering the shoe is in the angle between the sole and 

 heel or in the crevice between the upper and the sole, a crack of some 

 kind seeming to be necessary to enable them to get sufiQcient purchase to 

 commence boring. 



The full-grown larva (Plate VI, Fig. 2 &, c) i^ a thick, hairy, brown 

 grub about IS'""' long and one-fourth as broad. It tapers somewhat 

 from the thorax to the anal end, which is blustly pointed and armed 

 with a pair of thorn-like projections. There is a pale longitudinal stripe 

 down the back, and the six true legs are long and strong and of a red- 

 dish-brown color. With these it crawls raj^idly with a quick, darting 

 motion, dragging the hind body on the surface over which it is passing. 

 The six posterior joints are each armed above with a transverse row of 

 retrorse thorns, the purpose of which is dilficult to surmise, unless it is to 



* See Am. Naturalist,Ma,j, 1883, p. 457. 



