BUREAU OF ENTOMOLOGY. 215 



development of a protector to be sealed tightly around the base of 

 peach trees to effect the total exclusion of the larvae. Experiments 

 with protective washes applied by means of a spray pump to the 

 base of peach trees were carried to completion, but none of the sprays 

 tested proved to be adequately effective. 



Large-scale tests in orchards with dust sprays for the control of the 

 plum curcuho on j)each were begun in the spring of 1915 in Mary- 

 land, West Virginia, and Michigan. The data obtained indicate 

 effective control of the curcuho by the use of powdered arsenate of 

 lead. The poison is combined with finely divided sulphur and a 

 diluent, as lime or gypsum, with the view to effecting combination 

 work against the curcuho, brown rot, and peach scab. 



Grape insects. — The biological studies of the grape Phylloxera in 

 California, while practically completed by the faU of 1914, have been 

 continued in order that further information might be obtained con- 

 cerning the nymphal and winged forms of the insect. A report on 

 these studies is practically completed and will be submitted for pub- 

 lication by the close of the season. The renovation work in phyl- 

 loxerated vineyards has been continued, and in addition to determin- 

 ing the effects on the vines of deep plowing, fertilization, etc., experi- 

 ments are being made with carbon bisulphid injected into the soil for 

 the destruction of the insects in accordance with methods found 

 effective in Europe. In cooperation with the Bureau of Soils, a study 

 is bemg made of the relati'on of Phylloxera injury to different types of 

 vineyard soil. 



Field experiments in the control of the grape-berry moth in the 

 Lake Erie Valley have been continued along principally three hnes, 

 as outlined in the preceding report, namely, the use of arsenical 

 sprays, hand picking of infested fruit, and the covering of fallen 

 foliage in vineyards by fall plowing. In response to requests from 

 vineyardists, investigations have been made to determine the status 

 of the insect in northern Ohio, where it is causing considerable 

 injmy. 



Nut insects. — Material progress was made during the last fiscal 

 year in the studies of pecan insects in the South. A large amount of 

 data has been accumulated. Fairly complete information has been 

 obtained on the life history of the leaf case-bearer, the nut case-bearer, 

 and the shuckworm. Numerous other species have been studied, 

 such as the budmoth, the cossid borer, and the twig girdler. In the 

 experiments m the use of arsenicals on pecan it has been found that 

 the foliage is very tender, and that these must be used with caution. 



Orchard insecticides and spraying machinery.— Work on 

 orchard insecticides and spraying machinery has been continued about 

 as last year, and has included the testing of miscellaneous proprietary 

 insecticides. Further tests in apple orchards have been made with 

 arsenate of lime, and the results now leave httle doubt that this 

 arsenical, which costs about one-half as much as arsenate of lead, 

 will be a satisfactory substitute for the latter. 



Nursery insects. — Studies of nursery insects were undertaken 

 in the fall of 1913, and comprise an investigation of deciduous-fruit 

 nursery insects and the development of methods of control practical 

 under nm-sery conditions. Especial attention was given during the 



