156 EXPEBIMENT STATION RECORD. 



of adults varied from 20 to 41 days, averaging 25.69 days for the individuals 

 under observation. . . . Moths began to emerge June 17 from larvae and pupae 

 collected under bands June 5. reaching a maximum emergence some 2 vs^eeks 

 later, July 4 to 15. . . . From the earliest appearing eggs in spring, about April 

 15. to the first appearing moths, June 17, gives some 63 days as the approximate 

 length of the life cycle of the first generation. The laboratory records for indi- 

 viduals kept in breeding cages give a life cycle of 71 to 78 days." 



In <1909 the second-brood eggs were first found on July 7 at which time 5 

 larvae that had just hatched, none of which had entered the fruit, were dis- 

 covered. In rearing cages eggs were deposited in large numbers from July 

 8 to 10. The time required for incubation was less than half that required 

 for the first-brood eggs. In cages it varied from 7| to 9i and averaged 8J days. 

 The first larvjie to hatch out in the laboratory did so on July 32. The first 

 picking of pears in the orchard where the spraying experiment was carried out 

 in 1909 began July 15 and lasted 5 days, during which time young larvae were 

 hatching and entering the fruit in numbers in the unsprayed block so that even 

 the earliest first picking of fruit did not wholly escape the second-brood larvae. 

 In 1910 many second-brood larvae were in the fruit before the first picking. 



An average of about 26 days was found to be required for the development 

 of larvae in sound or nearly sound fruit out-of-doors at the laboratory in 1909. 

 " The first larvfe not pupating but going into winter cocoons in 1909 were taken 

 from bands July 17. Of 78 larvae taken on this date, 38 pupated and adults 

 emerged. 28 died, and 20 went through the winter as larvae. Of 196 larvae and 

 pupae collected under bands on June 28. 1910. 5 did not pupate but wintered 

 as larvae in cocoons." In 1909 the maximum number of larvae and pupae was 

 collected on June 26, while in 1910 the greatest number was found nearly 2 

 weeks earlier, on June 14. Tables giving the band records and emergence of 

 moths for Walnut Creek and Suisun sections show the maximum emergence 

 of moths to be about 3 weeks earlier than the maximum emergence at San 

 Jose. 



No parasites were reared during the course of the work, but an occasional 

 carabid larva was found under the bands eating the larvae and late in the 

 season a number of tenebrionid beetles (Eulabis ruflpes) were found under 

 the bands with partly eaten larvae, although in no case were these beetles ac- 

 tually found eating the larvae. The effect of sprays on the places of entrance 

 into pears by larvae and commercial results from spraying are reported in 

 detail. All of the plats receiving the first spraying (soon after the falling of 

 the petals) showed a comparatively light infestation at the calyx, and those 

 receiving the two early sprayings had very few pears wormy at the calyx. 

 Those plats on which the first spraying was omitted had a greater percentage 

 of pears wormy at calyx, although they received one thorough spraying just 

 before the first-brood worms began to enter the fruit. 



The author finds that as the first-brood larvae begin entering the fruit about 

 a month after most of the petals have fallen, though this time may vary some- 

 what with the season, all spraying for the first brood should be completed 

 v/ithin 3 to 4 weeks after the blossoms are off the trees. Two applications for 

 this brood reduced the worms for the season from 9.62 to 18 per cent lower 

 than the plats sprayed once. Two, and preferably 3, treatments are advised, 

 using arsenate of lead at the rate of 4 lbs. to each 100 gal. of water. The 

 first application should be made as soon as most of the petals have fallen : 

 especial pains should be taken to fill as nearly as possible each calyx cup 

 with the poison, and the trees should be drenched. The second treatment 

 should come 3 to 5 weeks after the falling of the petals. The third application 

 should be given 9 or 10 weeks after the falling of the blossoms, or about 2 



