Proceedings, ]9"23 179 



from tlie cxiimiiiatidii of a liTcat many lai'vac duriiifi' May, it was fciund 

 tliat 83',; of the larvae attaeked twi.us and 17',' attaeked fruit. 



Tlie injury to peacli twig jirowth was more apparent than that on 

 ajirieots. Tliere was a slight wilting of the leaves in the initial attack, 

 resembling the curl caused by aphids, followed by a distinctive withering 

 and a darkening of the green color of the foliage, which becomes discern- 

 ible by experience. With apricots the twigs grow faster and stronger 

 than peaches and the wilting is offset, thus making determination of 

 infestation difficult. 



During June, twigs attacked in May recover and new growth forms 

 to rejjlace the wilted portions. Often a small cluster of dead leaves will 

 be seen, particularly in apricots, with the new twig growth continuing 

 without interruption. Sometimes where marked injury has been caused 

 and the terminal bud destroyed, growth starts at other j^oints on the 

 stem. In a severe attack "twiggy"" formation is a characteristic sign of 

 previous infestation. 



Pupation of First Generation 



Full grown larvae measuring 12 to 15 mm. in length were found on 

 May Kith. IDllI, preparing to pupate. A few days later pupae were 

 formed. These were located, for the most part, in cracks and crevices 

 of the bark in the main trunks and larger limbs. Beneath flakes of loose 

 bark, within the characteristic curls of bark tissue and in the longitudinal 

 cracks in the main trunk, were common locations, particularly on apricots. 

 By the end of ilay it was almost impossible to find any larvae in the 

 fruit or twigs, those found being full-grown, but pupae were plentiful. 

 A few full-grown larvae were observed within the fruit of apricots on 

 Ma.v 17th, but in general almost the entire generation were in the pupal 

 stage by June 1st. In 1919 the first pupae observed were those bred 

 under insectary conditions from larvae 3 to 4 mm. in length taken on 

 May I'nd. These commenced to jiupate on May 28th.- Under field condi- 

 tions in this year full-grown lar\ai' were observed in the orchards on 

 June 6th, but all had disappeared and had formed pupae on June 16th. 

 The length of life of individual larvae vai'ied from 3S days to 57 from 

 the spring emergence from hibernaeula. and the pui^al jieriod in each 

 year lasted 14 days to 3 weeks. 



Ejiercjence of Midsummer iloTiis 



In 1918, the last week of May saw the tirst appearance of adults, 

 iloths at Kaleden were seen on apricots on May 29th, and in the tirst 

 two weeks of June they were common in the orchards at i'enticton, and 

 some were seen in the first week of Jul.v. In 1!>19 niolhs were observed 

 on June 16th and remained common for a full month. 



Eggs were seen, on occasion, shortly after the appearance of adults 

 in each year, on new twig growth. Difficulties in rearing moths in cap- 



