136 



Forty-fifth Report on the State MusEmi. 



University Experiment Station, 1883, p. 158. As the publication is 

 not accessible to many, the description is quoted : 



When the larva has made a mine from one-half to three- fourths inch 

 long, which it does in from four to five days, it eats its way out through 

 the upper surface ; then somewhere on the upper surface of the leaf it 

 weaves a circular silken covering about one-twelfth inch in diameter. 

 Stretched out on this network, the larva, which is now 2.6 mm. long, 

 makes a small hole in it near its edge, then, as one would turn a somer- 

 sault, the larva puts its head into this hole and draws its body after. 

 Arriving inside the "molting cocoon," as it may be termed, on its 

 back and doubled in the shape of a horseshoe, the larva is then ready 

 to strengthen the cocoon and close the opening which it made in enter- 

 ing. The larva^ make these cocoons in from fifteen to thirty minutes, 

 and usually wnthin two hours after leaving the mine. * * * Having 

 molted, the larv;e leave their cast-off skins in the molting cocoons and 

 cut their way out; they remain in these cocoons in most cases less than 

 twenty-four hours. 



The molting cocoon is represented at b. Figure 2, showing its 

 peculiar central spot, or depression, or both. 



The Cocoon. 

 The cocoon is a pretty little object with its five, or sometimes six, 

 sharj) ridges,* of which four are seen in a dorsal 

 view, crossing over its entire length from one end 

 to the other in parallel lines and uninterrupted 

 except as they may be broken near one end 

 where the cocoon is joined in its construction. 

 Tlie base is flat; the ends rounded; color, yellow- 

 FiG. 4-Cocoon of the grcen. Length, 0.15 to 0.19 inch; breadth, 0.05 



birch-leaf Bucculatrix, • , 



BUCCOLATRIX CaNADEN- mCU. 



sisklla; side view and t. • •, j'«? . • £ j.i^ a. c 



from above (original). it IS quitc diflerent in appearance from that oi 

 ^^<cc^^^«^;7^>'7)o»^^yo^^W^rt Clem., in several particulars, viz.: in its yel- 

 low-green color, instead of 

 white; its sharper and more 

 distinct ribs; its rounded in- 

 stead of pointed ends; its base 

 flattened to nearly its broadest 

 diameter in place of being 

 strongly contracted at the 

 sides; its ridges distinct to 

 the extreme tips instead of 

 uniting near them; and the 

 more conspicuous joining of 

 the cocoon near one end 

 coons are 







-j—i 



Co- ^IQ- 5.— Apple-leaf Bucculatrix, Bdcculatrix pomi- 

 foliella; a, piece of twig covered with cocoons; 6, 

 represented in cocoon enlarged: c, the moth, enlarged. 



*Mr. Fletcher (loc. cit.) gives "about eight prominent ridges," and Dr. Packard, "eight 

 sharp, high ridges." I never saw them with so many. 



