LEPIDOPTERA. 367 



perfection and providing for another brood of moth-worms in the 

 autumn. The little worm-like caterpillars, as soon as they are 

 hatched, disperse, and each one selects a single grain, into which 

 it burrows immediately at the most tender part, and remains con- 

 cealed therein after the grain is harvested. It devours the mealy 

 substance within the hull ; and this destruction goes on so secret- 

 ly, that it can only be detected by the softness of the grain or the 

 loss of its weight. When fully grown this caterpillar is not more 

 than one fifth of an inch long. It is of a white color, with a 

 brownish head ; and it has six small jointed legs, and ten ex- 

 tremely small wart-like proplegs. Duhamel has represented it 

 as having two little horns just behind the head, and two short 

 bristles at the end of its tapering body. Having eaten out the 

 heart of the grain, which is just enough for all its wants, it spins 

 a silken web or curtain to divide the hollow, lengthwise, into two 

 unequal parts, the smaller containing the rejected fragments of its 

 food, and the larger cavity serving instead of a cocoon, wherein 

 the insect undergoes its transformations. Before turning to a 

 chrysalis it gnaws a small hole nearly or quite through the hull, 

 and sometimes also through the chaffy covering of the grain, 

 through which it can make its escape easily when it becomes a 

 winged moth. The insects of the first, or summer brood, come 

 to maturity in about three weeks, remain but a short time in the 

 chrysalis state, and turn to winged moths in the autumn, and at 

 this time may be found, in the evening, in great numbers, laying 

 their eggs on the grain stored in barns and granaries. The moth- 

 worms of the second brood remain in the grain through the win- 

 ter, and do not change to winged insects till the following sum- 

 mer, when they come out, fly into the fields in the night, and lay 

 their eggs on the young ears of the growing grain. When dam- 

 aged grain is sown it comes up very thin ; the infected kernels 

 never sprout, but the insects lodged in them remain alive, finish 

 their transformations in the field, and in due time come out of 

 the ground in the winged form. 



It has been proved by experience that the ravages of the two 

 kinds of grain-moths, whose history has been now given, can be ef- 

 fectually checked by drying the damaged grain in an oven or kiln ; 

 and that a heat of one hundred and sixty-seven degrees, by Fan- 



