304 INSECTS INJURIOUS TO VEGETATION. 



on which there are only five, and on the first four rings, on 

 each of which there is an additional cluster low down on each 

 side ; the feet are brown, and there is a triangular brown spot 

 on the under side of each ring, beginning with the fourth. 

 The prickles are exceedingly sharp, sting very severely when 

 the insect is handled, and produce the same kind of irritation 

 as those of the nettle. When young, these caterpillars keep 

 together in little swarms. They do not spin a common web, 

 but, when not eating, they creep under a leaf, where they 

 cluster side by side. In going from or returning to their place 

 of shelter they move in regular files, like the processionary 

 caterpillars {Lasiocampa processionea) of Europe, a single 

 caterpillar taking the lead, and followed closely by perhaps 

 one or two in single file, after which come two, side by side, 

 close upon the heels of these creep three more, the next rank 

 consists of four, and so on, the ranks continually widening 

 behind, like a flock of wild geese on the wing, but in perfectly 

 regular order. When about half grown they disperse, and 

 each one shirks for himself. At the age of eight weeks they 

 get to their full size, in the meanwhile moulting their skins 

 four times, and finally measure two inches and a half or more 

 in length. At this age they leave off eating, crawl to the 

 ground, and get under leaves or rubbish, which they draw 

 round their bodies to form an outer covering, within which 

 they make an irregular and thin cocoon, of very gummy brown 

 silk, that has almost the texture of thin parchment. As soon 

 as their cocoons are finished, the insects are changed to chry- 

 salids, in which form they remain throughout the winter, and 

 in the following summer, during the month of June, or begin- 

 ning of July, they come out in the winged or moth state. 

 The scientific name of these moths is Saturnia lo* Unlike 

 those of the genus Attacus, they sit with their wings closed, 

 and covering the body like a low roof, the front edge of the 

 under wings extending a little beyond that of the upper wings, 

 and curving upwards. The two sexes differ both in color and 



* lo, a priestess of Juno, in Greece, jifterwards became the wife of Osiris, the 

 king of Egypt, and received divine honors under the name of Isis. 



