1066 EXPERIMENT STATION RECORD, 



parts of Oregon for the purpose of determining the extent of infestation of apple 

 orchards by the codling moth. With regard to the question of the number of 

 broods, it is believed that there are only 2. The various statements which have 

 been made to the effect that 3 or -4 broods occur are not based on breeding records, 

 but simply on the fact that larvae and eggs may be found throughout a long season 

 and that the different stages of the insect may ]je i)assed througli in a comparatively 

 short time under favorable conditions. The insect is described in its different stages 

 and an account is given of its life history. At Corvallis there appears to be no rela- 

 tion between the time at which the apple trees bloom and the dates on which the 

 moths emerge. Egg laying is delayed to a later date than that usually given in the 

 Eastern States. The first eggs were observed out of doors on June 21 and deposition 

 of eggs did not become general until June 28; the i)etals had fallen by April 28, or 2 

 months i^revious. Observations dunng the years 1898 to 1900 showed that while the 

 blossoms fell at dates ranging from April 28 to May 10, the egg laying did not begin 

 before the middle of June and did not become general before about June 25. In 

 southern and eastern Oregon the egg laying may take place earlier. 



A compilation of the records of the evening temperature in the neighborhood of 

 Corvallis disclosed the fact that the temperature rarely reaches 60° in the evening 

 during the month of May. Oljservations indicate that the codling moths rarely 

 deposit eggs when the evening temperature falls much below 60° F. The eggs were 

 found by the author in orchards at all times from the latter part of June until Octo- 

 ber 1, or later. They were found more commonly upon the fruit than upon the 

 leaves. The length of the larval period was found to vary from 16 to 24 days. In 

 breeding cages the moths of the first brood appeared on August 3, from larvae which 

 had pupated on July 21, and the moths of the second brood emerged on May 29 of 

 the following j^ear from eggs which had hatclied September 12. 



Notes are given on the various natural enemies of the codling moth, including 

 fungus diseases, parasitic and predaceous insects, and birds. While large numbers 

 of the larvae of the cotlling moth are destroyed l)y fungus disease, it is not believed 

 that this fungus could be successfully used in an artificial way in controlling the pest. 

 The most important help in the destruction of the codling moth is rendered by birds 

 of various species. 



The greatest loss from the codling moth in the Willamette Valley and other parts 

 of Oregon occurs after August 1. Spraying experiments were conducted for the pur- 

 pose of determining the relative efficiency of early and late ajiplications. Four 

 applications were made with Bordeaux mixture to which 1 lb. of Paris green was 

 added for each 200 gal. The api)lications were made on May 13, June 11, June 25, 

 and August 11. One or more of the ajiplications were omitted from scjme of the 

 trees in order to determine which application was most important. These experi- 

 ments showed that up to July 20 only 2 per cent of the apples were infested, 

 whether they had been sprayed or not. The first application seemed to be valueless, 

 and the second and third nearly so, while the fourth was apparently the only 

 effective one. Similar ex]jeriments wero repeated for 1900, the applications being 

 made May 7 to 14, June 22 to 27, July 26 to 28, and August 31 to September 1. In 

 these experiments the least satisfactory results were ol>tained with Ben Davis, of 

 which about 30i)er cent were wormy; Newtown pippins standing near them in the 

 same orchard were almost absolutely free from codling moth, while the Baldwins 

 were infested to the extent of about 1 or 2 per cent. Trees that were given the last 



3 applications showed less than 5 per cent infestation, while those that were sprayed 



4 times were infested to the extent of 3 per cent. It is believed that in order to 

 prevent injury from codling moth as far as possible the fruit should be kept covered 

 with a film of poison from the time when the earliest eggs are deposited until the 

 middle of September. The author believes that the expense of banding is hardly 

 necessary where spraying has been carefully done. 



