OF WASHINGTON, VOLUME XVI, 1914 155- 



is primitive. Utilizing Dyar's numbers, these setae may be in- 

 terpreted as follows: I, II, IV, V, and VII, nearly in a line on the 

 posterior annulet of the segment; VI small and a little in front of 

 this line; III obliquely above and behind the spiracle, with a mi- 

 nute IIIA obliquely before the spiracle. Besides these, there are 

 two minute spines (x) on the dorsal half of each joint. Thoracic 

 legs and abdominal prolegs are wanting. 



The larva is full grown about ten days after the hatching of the 

 egg. It then cuts a small semi-circular slit in the upper epider- 

 mis of the leaf, and leaves the mine, dropping to the ground, 

 where it at once digs down until it finds a suitable place in which 

 to make its cocoon. Normally this is attained within a few inches 

 or even less from the surface of the ground, often next to a stone. 

 but in the breeding jars 1 some went down six to eight inches and 

 there are records of even greater depths, depending presumably 

 upon the nature and humidity of the soil. There the larva bends 

 itself into a circle and pushes the soil aside to make a small firm 

 cell in which it then spins its oval cocoon. 



The cocoon is so tight fitting around the larva and is made of 

 so closely woven tough silk that it is difficult to cut it open with 

 dissecting needles without injuring the larva within. The cocoon 

 is about 2 mm. by 4 mm., of whitish silk and with small grains 

 of earth and sand firmly incorporated in its surface. The larva 

 remains within this cocoon apparently unchanged during summer 

 and fall, and not before sometime during the winter does it trans- 

 form into a pupa, which also very nearly fills out the cocoon. 



The pupa (figs. 19-20-21) is most extraordinary, unlike any 

 other Lepidopterous pupa, and reminding one much more of those 

 of Trichoptera. It has all appendages free and unfused and all 

 the body segments movable. The head especially can be moved 

 up and down and sideways. There is, of course, no room within 

 the narrow confines of the cocoon for these movements, but if a 

 pupa is taken out and lightly touched with a brush, it responds 

 with the most grotesque nodding of its head and with the swing- 

 ing out of the enormous mandibles in a deliberate manner. AVhile 

 all of the other appendages are loose, not glued together as is nor- 

 mal in a Lepidopterous pupa, it is mainly the head and the 

 mandibles and abdominal segments, which are movable and which 



1 Common large flower pots were used. These were filled with clean 

 sand and sifted soil, liberally mixed with small pieces of rock, and the 

 mined leaves were laid on top thereof. As soon as the larva? had left the 

 leaves, these were taken away, The pots were then buried flush with the 

 ground, inside an unheated breeding house, where they were sheltered from 

 sun and rain, but still exposed to nearly outdoor temperature during the 

 winter. The pots were watered half a dozen times from May to the follow- 

 ing January, and were then placed within breeding cases for the emergence 

 of the moths. 



