224 CATERPILLARS AND THEIR MOTHS 



pillars were slate-gi'ay all over, some being more pur- 

 ple-gi'av than others, and all looking shiny. The anal 

 segment was redder than the rest of the body, and the 

 shield was rough. The horn was black, and from it 

 were black lines extending to the last pair of -spiracles. 

 The spiracles were black encircled with white. Some 

 of the larvae were green through all the stages, and in 

 the last one had a yellow substigmatal ridge. 



The fourth molt followed in three days, and the 

 caterpillars were just as after the third molt, but 

 larger. They grew to a length of two and a half 

 inches or a little less, and tapered from the eleventh 

 segment to the head. 



The photograph does not give a fair idea of the 

 slender, shining caterpillar, because the only one we 

 could find when we wanted to photogi'aph him for the 

 book was too near pupation and had begun to shrink. 



Pupation followed the fourth molt in five days. 

 The pupa is dark and shining, and is formed in the 

 ground out of doors. 



The food-f)lants are willow and poplar, and the cat- 

 erpillars are found in August and September. 



Beginners usually mistake the caterpillars for sphin- 

 gid larvae, because of the caudal horn. In Pheosia ri- 

 mosa this horn starts as a tubercle, which is exactly the 

 reverse of the process in sphingid larvae. They have the 

 horn when they leave the egg, if they have it at all, and 

 in some cases, asj^oidonis, abhotii, and acliemon, lose the 

 horn and have a tubercle in its place in the later molts. 



The moth of Pheosia rimosa is very pretty, white, 

 gray, and brown, the female being darker than the 

 male. 



