3°4 



THE GUIDE TO NATURE. 



is dragged slowly after. Placed on a 

 smooth surface, as a piece of glass or 

 varnished table top, the insect has a 

 difficult time in propelling itself for- 

 ward. In every case it reminds one 

 somewhat of a slow train of cars, the 

 head and first three segments repre- 

 senting an overloaded freight engine. 

 Although the grub is exceedingly com- 

 mon, the pupa and the beetle into 

 which it transforms are quite rare. 

 This is because the larvae are com- 

 monly a prey to those busy little birds, 

 the woodpeckers and nut hatches. 

 The abundance of the larvae is ex- 

 plained by the fact that each beetle 

 having, by sheer good fortune reached 

 maturity, lays a great number of eggs, 

 one at a time here and there, in the 

 crevices of decaying bark. 



But the birds are not its only enemy. 

 Large predaceous beetles sometimes 

 kill it, probably it also has a parasite. 

 The common little red centipede, Scol- 

 opendra, almost as flat as the grub 

 and a hundred times more active, some- 

 times attacks, kills and devours, in 

 part, the under bark grub. Hundred- 

 legger is a common name for this sav- 

 age little creature, though actually it 

 generally has but from twenty-four to 

 thirty-eight legs. The centipede fol- 

 lows the burrows of the larvae or 



crawls at random under the loosening 

 bark. Sometimes it will crawl over a 

 larva without attacking it, at other 

 times it will seize the beetle larva at 

 once and if the centipede is about the 

 size or less than its intended victim, 

 there is a struggle, the grub moving 

 far more quickly than usual. 



The Cocoons on the Sassafras Tree. 



BY W. E. BRITTON, STATE ENTOMOLOGIST, 

 NEW HAVEN, CONN. 



I wonder if every reader of The 

 Guide to Nature has not at some time 

 or other seen the queer club-shaped 

 cocoons hanging from the bare 

 branches of the sassafras tree or the 

 wild cherry. They were made during 

 the preceding summer, and represent 

 the chrysalis or pupa stage of one of 

 our commoner species of large moths, 

 called the Promethea moth, Callosamia 

 promethea Drury. The caterpillar 

 feeds upon the sassafras, wild cherry, 

 and sometimes the plum, and is shown 

 in figure I. 



Including the stem, the cocoon is 

 about three inches long, and is usually 

 formed by rolling up a leaf and mak- 

 ing the cocoon inside it after having 

 spun and wound many threads of fine 

 silk about the leaf petiole and the 

 twig to which it is attached as is shown 



FIG. 1. THE PROMETHEA CATERPILLAR. FIG. 2. THE COCOON ROLLED IN A LEAF 



FIG. 3. THE MOTH JUST EMERGED. 



