- 577 h 
increased its effectiveness. Nicotine sulphate (1:1,200) with 5 It), 
hydrated lime in 40 gal. destroyed all eggs in all stages of development. 
DOZER, Hi L. (2417) 
1926. DEPARTMENT OF ENTOMOLOGY. Del. Agr. Expt. Sta. Bull. 147 (Ann 
Rept. 1925-1926), pp. 17-20. [Abstract in Rev. Appl . Ent . (A) 15: 
149-150. 1927.] 
Nicotine sprays did not control adult ' grape leaf hoppers ( Ery - 
throneura cones Say) very satisfactorily. Calcium cyanide dust was 
demonstrated to have "better killing powers than nicotine-lime dust, 
out a few growers used 2 percent nicotine lime dust with good results, 
the cost being about 20 s. an acre- 
HAMILTON, C C, and GEMMELL, L. G. (2418) 
1954. SOME 7IELD TESTS SHOTTING THE COMPARATIVE EFFICIENCY OF DERRIS, 
PYRETHRUM AMD HELLEBORE POTCDSRS ON DIFFERENT INSECTS. Jour. Econ. 
Ent. 27: 445-453. 
Heavy applications of a dust containing 1.5 percent nicotine 
knocked down the grape leafhoppers ( Srythroneur a comes Say.) but did 
not kill them. Cultivation with a disc cultivator before leafhoppers 
recovered gave a satisfactory kill with the nicotine dust (p. 453). 
SEVERIN, H. H. p., HARTUNG, T7. J., SCHT7ING, E. A., and THOMAS, T7.T7. (2419) 
1921. EXPERIMENTS TJITH A DUSTING MACHINE TO CONTROL THE BEET LEAFHOPPER 
( EUTTETRIX TSNELLA BAKER) TJITH NICOTINE DUST. Jour. Econ. Ent. 14: 
405-410, illus. [Abstract in Rev. Appl. Ent. (A) 10: 132-133. 1922.] 
An average of 92.5 percent of leafhoppers in cages were dead in 48 
hours after treatment with freshly made dust containing 10 percent of 
40-percent of nicotine sulphate. It was evident that with a redaction 
of 84 percent of the leafhoppers in' a dusted acre of beets, a marked de- 
crease in the percentage of curly leaf would occur in isolated beet fields 
SEVERIN, H. H. P. (2420) 
1922. CONTROL OF THE LEAFHOPPER. Facts About Sugar, N.Y. 14 (15 and 17): 
312-313 and 332-333. [Abstract in Rev. Appl. Ent. (A) 10: 396. 1922.] 
Tests against leafhoppers ( Sutettrix tenella Baker) with nicotine 
dust showed that from four to six applications were necessary to control 
the spring brood, but this would be too expensive in the natural breeding 
a,rea . 
HOWARD, F. K. (2421) 
1921. NICOTINE DUST FOR GRAPE LEAFHOPPER. C a lif. Cult. 56 (21): 671 and 
378. [Abstract in Rev. Appl. Ent. (A) 10: 169. 1922.] 
Adult grape leafhoppers ( Typhlocyba comes ) are so active as to 
avoid satisfactory contact with dusts. It is recommended that the dust 
