- 574 - 
WRIGHT, 17. H. (2402) 
1933. WALNUT APHIS CONTROL. Calif. Dept. Agr. Monthly Bull. 22 (2-3): 
166-169. [Abstract in Rev. Appl. 2 nt. (A) 21: 595. 1933. ] 
TThen the outbreak is slight and there are not more than 6 indi- 
viduals per leaflet, control may be obtained by the application of a 
dust of 3 percent nicotine sulphate (Rev. Appl. Ent . (A) 8: 130; 10: 
286) . Heavily infested trees should be dusted twice at an interval of 
2-5 weeks with a 3.5 to 4 percent dust. 
RIPPER, ff. (2403) 
1934. THE CONTROL OF HEAVY INFESTATIONS CF THE BEET LEAF APHIS. 
Neuheiten pflanzenschutz . 27 (3): 55-58. [In German. Abstract in 
Rev. Appl. Ent. (A) 22: 507-508. 1934.] 
Complete control was obtained on a small scale by a spray 
containing 2 percent soft soap and 1 percent spirit, and in large 
areas by a dust of nicotine sulphate with an inert carrier (1:19) 
applied at the rate of 124 lb. per acre. 
b. Psyllids and Leafhoppers, 1921-1934 
KELSALL, A. (2404) 
1923. CONTROL OF ORCHARD PESTS. Nova Scotia Fruit Growers Assoc. 59th 
Ann. Rept. 1923, pp. 95-106. [Abstract in Rev. Appl. Ent. (A) 11: 
394-395. 1923.] 
Nicotine vapor projected from a dusting machine to control sucking 
insects has proved promising. Nicotine should be added to the spray 
if the apple sucker (Psylla mali ) is very numerous, and where a dust 
schedule is being followed a nicotine impregnated dust may be used. 
PARROTT, p. J. (2405) 
1922. CONTROL OF SUCKING INSECTS BY DUSTING. N. Y. State Hort . See. 
Proc. 67th Ann. Meeting, pp. 35-49. [Abstract in Rev. Appl. Ent. (a) 
10: 325. 1922.] 
The adult pear psylla. ( Psylla pyricola ) showed a marked susceptibil- 
ity to nicotine in dust and liquid forms. The effect of nicotine in dust 
and liquid form on apple redbugs (Lye; idea m endax ) , currant aphid Ojyjrus 
rib i s ) , and cabbage aphid ( Brev icoryne ( Aphis ) b rassicae ) have been 
described elsewhere (Jour. Boon. Ent. 15: 82-85. 1922.) . 
STRICKLAND, L. F. (2405) 
1922. CO-OPERATIVE EXPERIMENTS TJITH LIME-NICOTINE DUST AGAINST HARD SHELL 
NYMPHS AND ADULTS. N. Y. State Hort. Soc. Proc. 67th Ann. Meeting, 
pp. 55-65. [Abstract in Rev. Appl. Ent. (A) 10: 326. 1922.] 
A heavy lime-nicotine spray should be directed against the first-and 
second-brood nymphs of the pear psylla ( Psyll a pyricola ) , or an applica- 
Ll 
