EASTERN UNITED STATES. 333 



According to Professor C. V. Riley, the larva of this 

 species lives inside the stem and root of the Yucca, or 

 Spanish Bayonet, being the only one of our butterflies 

 that lives in the larval state as a borer on the inside 

 of the stems of plants, unless we include the allied 

 species M. Cofaqui. There is a probability that when 

 the life-history of that species is known it will be found 

 to have similar habits. The eggs are deposited singly 

 011 the leaves, and, when hatched, the larva conceals 

 itself in a web between some of the more tender ter- 

 minal leaves. Generally it will be found at first near 

 the tip of a leaf, where the sides naturally roll up and 

 afford a safe retreat. It then gradually works to the 

 base, feeding as it goes, and rolling and shrivelling the 

 blade as it descends. Other blades are often joined, the 

 insect living among the blades till it is about one-fourth 

 grown, seldom entering the stem before that time. 



The egg is subconical, the top flattened or depressed 

 and with a slight central dimple, the base concave, 

 smooth but not polished. Color pale green when first 

 deposited, but inclining to buff-yellow or brown before 

 hatching. The diameter is about .1 of an inch, the 

 height about .06. 



The young larva is about .2 of an inch long, of a 

 dark brick-red color, head and top of the second segment 

 pitchy black. The abdominal joints show two princi- 

 pal transverse folds. There are six rows of stiff black 

 hairs arising from the body or from very small tubercles. 

 Head larger than the second segment, rounded, but some- 

 what flat in front; cervical shield narrow and in one 

 piece ; both minutely punctured. No anal plate. 



The full-grown larva averages 2.6 inches in length by 



