24 B. C. ExTOiiOLOGiCAL Society 



sprays cdntaininu- arsenate of lead after the caterpillars have hatched. 

 In the control of the fruit-tree leaf-roller, tiiorouo:h covering and high 

 pressure are essentials. 



The Oblique-banded Leaf-Roller, Cacoecia rosaceana (Harris). 



Tlie past two seasons have witnessed a very considerable increase in 

 the numbers of this pest, and numerous enquiries have been received re- 

 garding its depredations. 



The life-history of the oblique-banded leaf-roller affords a good ex- 

 ample of the necessity of a clear understanding of the habits of an insect 

 in order that repressive measures may be intelligently applied in any 

 given locality. Prior to the year 1922 certain phases in the development 

 of this insect were not well understood, at least in so far as the interior 

 fruit-growing sections of the province were concerned. 



It was generally believed that the winter was passed in the egg 

 stage, and that the newly hatched larvae immediately attacked the open- 

 ing buds, and that its life history was more or less identical with that of 

 the fruit-tree leaf-roller. Recent observations, however, have shown that 

 this is not the case. The oblique-banded leaf-roller passes the winter in 

 the Okanagan Valley as a partly grown caterpillar upon the trees, within 

 the protection of a closely woven silken cocoon. Over-wintering cocoons 

 occur beneath flakes of dead bark, under bud scales attached to the fruit 

 spurs, or in other protected situations. These over-wintering larvae 

 emerge from their hibernating quarters in early spring, as soon as the 

 buds begin to expand, and feed in much the same manner as do the lar- 

 vae of the fruit-tree leaf-roller, which they closely resemble. Maturity 

 is reached in July, and the adults are on the wing about the middle of 

 that month. 



The eggs of the oblique-banded leaf-roller are deposited upon the 

 upper surface of the leaves of apple and other orchard trees during the 

 month of July. A number of eggs are laid together in a flattened oval 

 mass, and are of a pale green colour, closely resembling the leaf surface 

 to which they are attached. Individual egg masses appear as blots of 

 tinted wax, and each mass may contain from 15 to 100 eggs or more. A 

 short time before hatching, the black heads of the larvae may be distinct- 

 ly seen within the eggs, the masses appearing as though finely stippled 

 with black dot.s, arranged in symmetrical lines. An interesting point 

 regarding the hatching of the eggs of the oblique-banded leaf-roller is 

 the brief period covered by the emergence of the larvae from a single egg 

 mass, all of which appear to mature at the same time, and emerge within 

 a few minutes of each other. The hatching of a fully incubated egg mass 

 may sometimes be brought about at a given time by jarring the leaf to 

 which the eggs are attached. 



The newly hatched caterpillars migrate to the under surfaces of the 

 leaves, and spin fine silken webs in close proximity to the main veins, 



