HABITS OF THE LARVA. 



The normal number of larval molts is five. This is the number which 

 we have observed during the autumn months, while in midsummer, when 

 the development is more rapid, we have on several occasions traced but 

 four. The term of larval existence varies from one to three weeks. 



There is a very general belief among planters that the first worms of 

 the season are pale and the late ones dark, and while both light and 

 dark worms may always be found together in sirring, summer, or fall, 

 it is true that the green ones predominate early in the season and the 

 dark ones later.^ 



Immediately after molting, the body is pale and without marking— a 

 rule with all molting animals. After the earlier 

 molts, the cast-off skin which remains more or 

 less fully stretched, is sometimes eaten. 



Some of the peculiarities in the habits of the 

 worm deserve mention here, because of their 

 practical bearing. 



Until after the second molt it always remains 

 on the under side of the leaf, feeding upon the 

 j)arenchyma, and leaving untouched the coars- 

 er veins, stomata, and upper skin or epidermis. 

 The leaves where they are thus feeding present 

 a blotched appearance, the semi-transparent 

 epidermis becoming pale yellowish, and these 

 blotches are, as a rule, at once distinguishable 

 from other somewhat similar ones made by a 

 few other insects.® 



After the worm begins to eat entirely through 

 the leaf, which is usually before the third molt, 

 but sometimes later, it instinctively ascends 

 toward the top of the plant and feeds on the^^^-^-^^'^^-^^°^'C°^^°^^^°^^^= 



- ^ ,. ,, • ^1 -J J ,1 a. from side; &, from back; twice 



more tender foliage, -^raggmg" it, to use the natural size. (After Eiiey.) 

 expressive language of the planter. 



It can let itself down by a web from the moment of birth, but can also 

 fling itself from one part of the plant to another in a manner quite 

 characteristic. The fling or jumj) is made by bending the fore and raised 

 part of the body to one side and then suddenly jerking it to the opposite 

 side, relaxing meanwhile the three hind pairs of legs by which it held to 

 the plant. This is a quite common mode of motion when disturbed, and 

 the normal way of getting from one plant to another. The maximum 

 distance which a worm can thus jump in a horizontal direction is about 

 two feet, and it almost invariably alights on its legs. During chilly 

 weather in autumn this motion is feeble and can be easily watched. 

 When not feeding, the worm either rests stretched straight on some 

 part of the plant or may be seen swaying its fore body from side to side, 

 holding the while by the hind prolegs. 



Though preferring the foliage, it will, when hard pushed, eat every 



