38 



N. S. ENTOMOLOGICAL SOCIETY. 



PREOVIPOSITION PERIOD. 



Our experiments on this point were partially destroyed by the great gale that blew 

 down the cages that had been erected over various trees, shortly after the flies were 

 liberated, and we were unable to get another large supply. It was shown, however, 

 in the cages, previous to the accident that egg laying may take place in as short a time 

 as four days after emergence. Since the flies do not breed normally in confinement, it 

 cannot be said with certainty that the preoviposition period would be the same for the 

 flies in the open. The only way to give this matter a cert ain test, would be to liberate a 

 large number of flies about an isolated, non-infested tree in the open, exposing a cer- 

 tain number of apples each day thereafter, the same as in the cage experiments. Prev- 

 ious experiments along this line have been inconclusive owing largely to lack of suffici- 

 ent material aaid the difficulty of getting a suitable tree for the experiment. We hope 

 to remedy these conditions in another season. 



FERTILITY OF EGGS. 



From observations made over several years it appears that the percent age^of 

 fertility varies greatly with the variety, season or time of the year. Our observations 

 were made this year with Gravenstein apples during the month of August. Out of 845 

 punctures examined 754 were found to contain eggs and of these 717 or 95.09 per cent 

 hatched. 



EFFECT OF CHEMICALS ON PUPAE. 



Our results showing the effect of various chemicals upon the pupae were incom- 

 plete last year owing to the two year life cycle of the fly. (Bull. 9, N. S. Dept. Agr.: 46). 

 We have now secured the final results from these tests, which only bear out our pre- 

 vious conclusion, viz., that this method of dealing with the pest is unsatisfactory. 



It is probably a coincidence that, in a number of cases, the emergence from the 

 treated cages is higher than in the untreated or check cages. At any rate there is noth- 

 ing to show that any of the so-called "soil fumigants," even when used very much strong- 

 er than recommended, have any deleterious effect upon the pupae. The detailed re- 

 sults are fully set forth in the accompanying table. 



