THE INSECT WORLD. 



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green caterpillars with broken black bands. A peculiarity of 

 this kind of caterpillar is that when touched or irritated in any 

 way it shoots out from between the segments close to the head a 

 forked, orange-colored process, which emits a very disagreeable 

 odor, and this is its only means of defence. No trace of the pro- 

 cess is visible when tiie insect is at rest, and the horns are with- 

 drawn just as soon as irritation ceases. When the caterpillar is 

 full grown it leaves the plants upon which it has fed and travels 

 to any convenient point in the vicinity where it can pupate. This 

 pupa, or chrysalis, is fastened to a little silken pad by the tail, 



Fig. 269. 



Papilio asterias. — Mature larva and pupa. 



but is also sustained by a silken band in front of the middle, so 

 that it is said to be girthed, and this same type we have in all the 

 members of this family. These caterpillars are rarely abundant 

 enough to become troublesome, but if they are, hand-picking is, 

 perhaps, as good a remedy as any. They are quite prominent, 

 and, therefore, easily and rapidly gathered, checking their injury 

 immediately and completely. When they are small, spraying 

 with the arsenites will answer, provided it be done thoroughly. 



Another species is P. philenor, of about the same size, black, 

 without the yellow spots through the centre, but with the upper 

 surface overlaid with greenish, powdery scales, which give the 

 insect a metallic lustre in certain lights, and this varies according 

 to the angle at which the light strikes the wings. The cater- 

 pillars feed upon vines of Aristolochia, or " Dutchman's pipe," 

 which they sometimes injure considerably. They are dull 

 brownish red in color, with long, fleshy filaments on the seg- 

 ments, and when irritated also extrude fleshy horns such as 



