164 Bulletin 235. 



of the copper sulfate as is usually used on apples, for the foliage of stone 

 fruits is often easily injured by it. At least two applications should be 

 made, one just after the blossoms drop and another about a week later, 

 I have no conclusive data to indicate that spraying before the blossoms 

 open will pay on the stone fruits. 



Recent experiments in other States. — In the middle West, the plum 

 curculio is a serious pest in apple orchards. In Bulletin No. 64, issued in 

 1904 from the Missouri Experiment Station, it is claimed that by spray- 

 ing apple trees with the arsenate of lead twice before the blossoms opened 

 and four times, at intervals of ten days, after the blossoms had fallen, 

 the damage by curculio was greatly lessened. This treatment combined 

 with the destruction of windfalls and thorough cultivation in July and 

 August controlled the pest in apple orchards in Missouri. 



As Bulletin No. 98, the Illinois Experiment Station issued in Febru- 

 ary, 1905, a very valuable and exhaustive account of " The Curculio and 

 the Apple." The conclusion from the use of a poison spray on apples 

 for the plum curculio after two years of careful experiments is that 

 " under favorable conditions from 20 to 40 per cent of the fruit liable 

 to puncture may be saved by five applications, and this treatment is re- 

 garded as profitable and practicable." For entirely satisfactory results 

 in apple orchards, the spraying must be supplemented by attack from 

 other directions, that is by the destruction of fallen fruit and especially 

 by cultivation. 



New York plum and peach growers usually pay little or no attention 

 to the destruction of the fallen fruit and thus allow the pest to breed 

 freely. The curculio is responsible for much of this fallen fruit and it 

 would aid very materially in the warfare against the pest if the fruit were 

 picked up and destroyed every few days. 



Cultivation for the plum cnrcuHo. — In both the Missouri and Illinois 

 Bulletins mentioned above, cultivation is strongly urged as a very effective 

 method for helping to control the curculio in apple orchards. In Illinois 

 they found that both the grubs and pupoe are very delicate and extremely 

 sensitive to exposure to sunlight and air, and that short exposures to 

 direct sunlight are fatal to the insect in these two stages ; that over 90 

 per cent of the grubs which leave the fallen fruits do not go more than 

 two inches into the soil to transform to the pup?e; and that nearly 90 per 

 cent of the grubs and pupse can be disturbed by cultivation within a period 

 of thirty days from July 10. Therefore, they recommended superficial 

 tillage of the apple orchards for a period of thirty or more days from 

 July loth. 



After reading these facts, I wondered if the growers of stone fruits 

 in New York had considered or had tried this cultivation method for the 



