PRocioEniMis, 19:24 2:3 



tliiit <if the ol)li(|ui.'-haii(lcil h'iif rdllcr is n m<ittcr (if iiitcri'st. and 1iu' 

 type of injury eausrd by Imtli species is identical. Peronea maximana 

 (B. and B.) was fii'st bred from apple foliaoe in 1921 at Vernon; tliis 

 constituted the first record of this insect as a species of economic import- 

 ance in the Okanagan. P'urther notes (,f an historical nature reyardin^ 

 this insect will be ii-iven under the life history on a later paye. 



In consichM-inu- the life histories of these four species of leaf-i-oller, 

 M-e may take tlieui in theii- oi-der (if iuiiiortance. . 



The Fruit Tree Leaf-Roller, Cacoecia argyrospila, (Walker). 



The control of this insect may at ]n-eseul be considered the most 

 serious problem facing the orchardists in the interior fruit growing sec- 

 tions of the Province. Extensive damage has been caused in many of the 

 commercial orchards in the Okanagan Valley, and although in 1922 these 

 areas were circumscribed, and fairly well defined, the insect, during 1923, 

 spread throughout the whole of the orchard sections of the Valley, be- 

 sides being reported from Creston in the Kootenays. 



The life-history of the fruit-tree leaf-roller may be briefly outlined 

 as follows; the winter is passed in the egg stage upon the trees, the eggs 

 occurring in small, greyish-brown, oval patches upon the bark of the 

 main limbs and twigs. The number of eggs in a single egg mass varies 

 approximately from fifteen to one hundred, or possibly more. The hatch- 

 ing of the eggs fi-om a single mass may extend over a period of from 

 about 24 to 48 hours, and occurs in May just as the buds are commencing 

 to expand. The young larvae at first attack tiie opening buds, and later 

 the blossoms and fruit, much of which is entirely destroyed, or so severe- 

 ly mutilated as to produce only scarred and deformed specimens at pick- 

 ing time. During July the larvae become mature, at which time they 

 appear as cylindrical, pale green caterpillars with dark heads. Foliage 

 injury is extensive, and considerable quantities of silk are spun by tlr; 

 larvae, which conceal themselves in nests formed from leaves tied to- 

 gether with silken threads. Pupation takes place within the protection 

 of tlie nest used by the caterpillar for concealment. Moths emerge, and 

 are on the wing during the latter part of July, and are active chiefly at 

 dusk. During the daytime the moths lie dormant amongst the foliage of 

 the trees, but large numbers may be observed in flight if the trees are 

 shaken, or disturbed. The eggs are deposited towards the end of the 

 month, and by early August all adults have practically disappeared. 



It will be seen that from 9 to 10 months are passed by the fruit-tree 

 leaf-roller in the egg stage, and it is during this period of its existance 

 ih;it controi measures should lie aiiplied. A]iplications of miscible oil at 

 an 8 per cent, dilution, put on in early sjiring, before any bud develop- 

 nu'ut has started, will give a good control, especially if thoroughness is 

 observed. Whei-e oil sprays are not used, it will lie necessary to ajiply 



