170 THE EEPOET OF THE No. 36 



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COMPAKISON OF THE LARV^. 



The larvae of all three species closely resemble each other both in appearance 

 and habits, and therefore will not be distinguished by the fruit growers. In the 

 early part of the season up to the time when the fruit begins to be attacked the 

 larva of the Oblique-banded species will nearly always be the largest of the three 

 [)ecause it reaches maturity earliest. It is, when full grown, nearly an inch 

 long,. green in color, with a black or blackish head and thoracic shield. 



The full grown larva of the Fruit-tree Leaf-roller is usually more of a pale 

 yellowish-green color ; it also has a black head and thoracic shield in all stages 

 except the last when these usually change to brown. 



The full grown Box-elder larva is like the above two in being nearly an inch 

 long. It is a very pale apple green color and can be distinguished from either 

 of the above species by the head and thoracic shield being a whitish green instead 

 of black. There is often a slight mottling of brown on these parts, and in some 

 specimens at least, the segments are indistinctly divided by pale yellowish-white 

 lines. There is a dark green line down the middle of the back. 



Comparison of the Pup^. 



It does not seem worth while to go into details in regard to the differences 

 between the pupge, further than to remark that those of the Fruit-tree Leaf-roller 

 and of the Oblique-banded species are brown, whereas those of the Box-elder 

 species are whitish both before and after the adults emerge. 



Life-Histories. 



The winter is passed by all the species in the egg stage on the trees. We 

 did not prove this of the Oblique-banded species because the larvas of the second 

 brood of this species all died in the cages, but Herrick, of Cornell, has ?hown that 

 eggs are laid by the second brood adults and the winter passed in that stage. 

 The eggs of all three begin to hatch near the same time, which is usually very 

 soon after the buds are beginning to burst. Almost all those of the Box.-elder 

 Leaf -roller and also of the majority of the Fruit-tree Leaf -roller had hatched by 

 May 3, which was a few days before the blossoms on the Spy began to burst. 

 At this date the larvre of these two species were still very small, being only about 

 ys inch long. Hatching of argyrospila eggs continued for a month, the last 

 newly hatched larva being seen June 8th. 



By May 25th the Oblique-banded Leaf-roller had begun to pupate and by 

 June 10 the first adult was seen. The latter date was about two weeks after the 

 blossoms fell from the Spy trees. The pupal stage of this species, judged from 

 the few specimens reared, lasted about 13 days. The larvae of the Fruit-tree 

 Leaf-roller began to pupate about June 14, but larvre were present for three weeks 

 or more later. Adults were first seen in the orchard on June 26th. After this 

 they soon became quite common. By July 12 they seemed to have reached the 

 maximum, and then quickly decreased in number, the last being seen on July 22, 

 The length of the pupal stage averaged 11.5 days. Adults in cages lived only 

 five or six days. 



The first pupa of the Box-elder species was found on June 26th, but there 

 must have been pupae earlier than this for adults were found on July 3rd, and 

 cage experiments showed that the pupal stage lasted about 12 days on an average. 



