CONTEOL OF THE CODLING MOTH IN NEW MEXICO. 7 



This table also shows the destructive influence of sprays in lessening 

 the actual number of larvse. Thus on Plat I, which received three 

 sprays, there was a total of 818 larvse for the season, on the five 

 count trees; on Plat II, which received four sprays, the number of 

 larvse for the five trees was 271; while on Plat III, which received 

 five sprays, only 148 codling moth larvse were found in fruit from the 

 five "count trees" during the year. The foregoing figures are in 

 marked contrast with the total number of larvse found in fruit from 

 the five unsprayed trees, namely, 23,570. 



RECOMMENDATIONS BASED ON THE FOREGOING RESULTS. 



While the results reported herewith are very clear-cut, the bureau 

 would not be warranted in formulating definite recommendations 

 based upon the work thus far carried out in the Pecos Valley were it 

 not for the reason that these results substantiate the results obtained 

 from a large series of spraying experiments against the codling moth 

 in many parts of the United States. In Table I, showing treatments 

 and dates of applications, the reader will note that the first applica- 

 tions were made with Bordeaux nozzles and the. later applications 

 with eddy chamber nozzles. Entomologists of certain Western States 

 who have experimented with the codling moth under arid conditions 

 insist upon the advantage of a coarse spray given at the time imme- 

 diately following the dropping of the petals. Tests of the compara- 

 tive value of coarse and fine sprays under eastern conditions show 

 that there is apparently but little difference as regards the effective- 

 ness in the control of the insect of a coarse and fine spray. The 

 Roswell experiments did not include a comparison of coarse and fine 

 sprays and no specific information can be furnished on this point, 

 and it would appear safer for the orchardist to follow the methods 

 used by Mr. Hammar until further information is obtained. It will 

 also be noted that spraying was done under high pump pressure. 

 This should not be construed to mean that effective work in the con- 

 trol of the codling moth can not be accomplished except by use of 

 power outfits working at high pressure. Very good results have been 

 obtained from the use of barrel sprayers working at perhaps 100 to 

 120 pounds pressure. 



The prime essential in the control of the codling moth is that the 

 treatment given immediately after the falling of the blossoms shall 

 be made with great thoroughness, in order to insure the lodgment of 

 poison in the calyx cup of each and every apple. This result is best 

 secured by so handling the spray rods that the spray is directed 

 downward into the upright clusters of the little apples. This spray- 

 ing especially should be made rather deliberately and with great 

 pains. Frequent examination of sprayed trees should be made to 

 determine how thoroughly calyx cups are being filled with poison. 



