Proceedings, I;)2;5 177 



years prcvidus to 1!.)17 that, in that year, i'nily .")()', of the fruit in tiic 

 nrehards was unmarketablt', while a lieavy h)ss was appai'ent with the 

 fi'uit taken to the paekiiiji- luuises. ]'eaehcs, ai:>i-ieots, prunes and eliei'ries 

 were beins' attaeked thi-oui:hout the Okanayan Valley. 



During' the winter of 1917-1918 enero'etic steps were taken at the 

 request of the growers by the Provincial Horticultural Department to 

 institute repressive measures against this insect. A campaign of spray- 

 ing was inaugurated in the spring of 1918, tlie measures taken being 

 adapted from recommendations made by the States of Washington and 

 ('alif(u-nia against this insert. During tlie course of the campaign of 1918 

 studies were begun by the writer, as an officer of tlie Dominion Entomo- 

 logical Branch, at Summei'hiinl. I'enticton and Kaleden, and efforts were 

 iiuide to harmonize the (level()))ing life history of the insect with the 

 s])raying camjiaign then in piogress. Similar studies were maintained 

 during 1919. A short cii-cular on tliis insect, its life history and control, 

 was prepared b.y the writer and issued and circulated by tlie Provincial 

 Department of Agriculture. This circular covered the essential features 

 of practical value to the grower. So far as I am aware no effort has been 

 made to present to entomologists the substance from -wliich this circular 

 was written. With this end in view, the following record is presented: 



( )VEK-WlNTEI{IXG 11 A HITS 



The adult of this insect is a minute moth Avhii'h may be found on 

 the wing in the orchards in considerable numbei-s during May and June 

 and again in August and September. In a normal year two generations 

 occur, the autumn brood of moths being pi-esent from early August until 

 late September, ovipositing freely on the twigs. The eggs hatch, giving 

 rise td larvae which over-winter. So far as our records go, the winter 

 is only passed in this larval stage. Commencing in August and passing 

 through September into October, these larvae, which are of an average 

 length of 2.5 mm., aftei* feeding to a slight extent on leaves, twigs and 

 fruit, form hibernacula. This hibei-naenlum is a minute gallery made 

 in the wood of the tree by the larvae. It is lined on the inside with silk 

 and a minute column of frass is thrown uj) on the outside. These columns 

 of frass are very distinctive and are readily seen, particularly when the 

 castings are fresh. They oecui- in the crotches of 1, 2, 3 and 4-year-old 

 wood of young orchards. When larvae are ])articularly numerous and in 

 older orchards, these hib(M-na<Mihi ai-c found, as well, in 5- and 6-year-old 

 wood, on the underside of boughs as well as in the crotches. Entrance 

 to the wood is frequently made through the stomala and in the softer 

 cambium growth surrounding pruning scai-s. As a result of an examina- 

 tion of several hundred hibernacula during 1918 and 1919, in commercial 

 peach and apricot orchards, by far the greatest number of larvae were 

 found in the crotches of 1- and '2-yeal•-(^ld \\'oo(l, usuall\- on the u|)pci' 

 sides and not underneath. 



While the larvae enter their hibernacula in the autumn. "_' mm. to 



