190 NORTH AMERICAN INSECTS. 



their spiny legs in contact with their wings ; or with 

 crickets, by rubbing their wings together; and with flies 

 and the different species of bees, who make a noise by the 

 rapid motion of their wings. 



Among many others we have every year attempted to 

 raise a number of these handsome caterpillars, but have 

 often been unsuccessful in bringing them to their final 

 metamorphosis, because, as soon as they were full grown, 

 they ceased to take food, became sick, and died. In such 

 cases we have noticed the surface of their bodies com- 

 pletely covered with small, shining, white silky-looking 

 grains, resembling minute seeds, and if one fell off its plact 

 was immediately supplied by another. These white speckr 

 were the silky cocoons of diminutive ichneumon-flies, 

 whose mother had stung the poor caterpillar when very 

 young, and deposited many hundreds of eggs in as many 

 hundred wounds. The larvae proceeding from these eggs 

 dwell between the skin and the fat of the caterpillar, on 

 which they feed, being very careful not to attack any vital 

 part of the body. Thus the unfortunate caterpillar is for 

 several weeks being slowly devoured, while it continues to 

 eat and to grow for the benefit of its tormentors, until all 

 its fat is consumed by these parasites, when, having no 

 strength or vitality left with which to accomplish its meta- 

 morphosis, it lingers along a few days, shrinks to the fourth 

 part of its former size, and finally dies in agony. Then 

 the small cocoons of the ichneumon-flies fall to the ground, 

 and a few days after assume their perfect form, and fly 

 about, after the example of their mothers, to seek new 

 victims. 



While on the subject of Hawk-moths, we can not^omit a 

 brief incidental notice of one species, which is a native of 

 the southern parts of Europe, because even now it spreads 

 a general terror among the ignorant and superstitious. 

 And we do this the more willingly, because many Ameri- 



