THE SWEET-POTATO LEAF-FOLDER. 5 



Measurements of the wing expanse of 11 reared females gave an average of 

 27 mm., ranging from 25 mm. to 29 mm. The wing expanse of 7 reared males 

 ranged from 25 mm. to 27 mm. 



FOOD PLANTS. 



In addition to the sweet potato as a food plant, moths have been 

 reared from larvae found feeding on uncultivated plants of the genus 

 Ipomoea, to w T hich the sweet potato belongs. It seems probable that 

 some species of this genus, known under the common names of " bind- 

 weed," "wild sweet potato," and 5 wild morning-glory," are the 

 natural larval food plants, and that the larvae will feed on any of 

 the numerous species of Ipomoea, in which genus are included a num- 

 ber of ornamental vines. 



SEASONAL HISTORY AND HABITS. 



OVIPOSITION. 



Eggs have not been observed in the field at Baton Rouge, but the 

 females, after feeding from pieces of* sponge moistened in sweetened 

 water, oviposited freely on sweet-potato plants in cages. 



The eggs, which are securely fastened to the leaf, were placed on 

 the underside, the areas alongside the leaf veins being a favorite 

 location; Mr. High, however, from observations made in Texas, noted 

 that apparently the eggs are deposited indiscriminately on either side 

 of the leaf. Eggs are sometimes placed singly but as many as five 

 have been noted in a group, their edges overlapping, although in no 

 regular arrangement. ._, -^ 



.'■. : """%, . 



INCUBATION. 



Eggs laid in the insectary at Baton Rouge qn July 29 and 30 

 hatched on August 2 and 3, respectively. The period of incubation 

 was, therefore, under these conditions, four days. The averages of 

 the daily maximum and minimum temperatures for the insectary 

 from July 29 to August 3, inclusive, were 92.5° and 74.0° F. 



HABITS OF THE LARVA. 



In the field the larvae are found between separate leaves or portions 

 of the same leaf which have been fastened together to form " shel- 

 ters," each of which usually protects one larva. The larva constructs 

 its shelter by spinning threads of silk from side to side across a por- 

 tion of a leaf near the edge, each strand being shortened as the pre- 

 ceding strands contract in drying, until finally the edge of the leaf is 



