2l8 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Nicotine Dusts, Notes on the Use of. By A. W. Morrill (Journ. Econ. Entom. 
vol. xiv. pp. 394-400, Oct. 1921). — The author comments on the striking variations 
in the efficiency of nicotine dusts under similar conditions ; showing that the 
factors inducing the variations are not yet understood. — G. W. G. 
Nicotine and Nicotine Combinations, Some Results with, in Experiments on 
the Control of Laspeyresia molesta, Busch. By L. A. Stearns {Jour. Econ. 
Entom. vol. xiii. pp. 364-367 ; Aug. 1920). — The results of the previous season's 
investigations had emphasized the necessity of increasing the spreading and 
sticking powers of the insecticides used, on account of the habit of this insect 
depositing its eggs on the under surface of leaves. For this purpose sea moss 
solution (prepared by boiling 4 lb. of Irish rock moss for one hour, straining 
and diluting to 50 gallons of water), and a casein-lime mixture (1 part casein 
to 3 parts hydrated lime, adding water at the rate of 50 gallons to 1 lb. of the 
admixture), were found to fulfil the requirements. The conclusions drawn 
from detailed laboratory experiments and limited field tests suggest the use 
of nicotine sulphate 40 per cent, diluted, 1 part to 800 parts of water, either alone 
as an ovicide or in combination with an arsenical near the time of hatching, 
or, better still, on the day the eggs were laid. Apparently nicotine sulphate and 
sea moss, with or without the addition of arsenate of lime powder (k lb. to 
50 gallons) secured a percentage efficiency for the spray of 80 per cent. — G. W. G. 
Nodule Bacteria in Leguminous Plants. By F. Lohnis and R. Hansen 
(U.S.A. Jour. Agr. Res. xx. No. 7, Jan. 1921, pp. 543-556; 2 plates). — 
The nodule bacteria are divided into two groups. The first group shows all the 
features characteristic of B. radicicola (Berijerinck). It is peritrichic, grows 
rapidly upon agar and causes milk to change ; it forms nodules on roots of clover, 
sweet-clover, alfalfa, vetch, pea, navy bean, lupin, black locust, Amorpha, and 
Strophostyles. 
The second group has monotrichic flagellation, very slow growth on agar, no 
marked change in milk. It is found on cowpea, soya bean, pea nut, Acacia, 
Genista, and Cassia. From this characteristic it should be named Pseudomonas 
japonica, or Bacterium japonicum (Kirchner), but the authors do not advocate 
this because its life-history is incompletely known. 
B. radicicola is closely related to B. radiobacter, which last appears to be 
usually present in nodules of leguminous plants ; but if grown on potato, B. radio- 
bacter can be easily distinguished by its brown growth from B. radicicola. 
A short bibliography is appended. — A . B. 
Oil Sprays, The Results of Using, for the Control of the Fruit-tree Leaf-roller in 
the Pajaro Valley, California. By Donald D. Penny (Journ. Econ. Entom. vol. xiv. 
pp. 428-433, Oct. 1921). — -The variable results obtained by oil-spraying for leaf- 
roller (Archips argyrospila Walker) control, suggested to the author that the 
different kinds of oils used might be one of the factors responsible. 
Experiments were conducted, therefore, with different emulsions of oils 
referred to as those of an Eastern or paraffin type, and oils of a Western or 
asphaltum origin. 
All the emulsions were prepared with 2*5 per cent, of cresol soap. 
The best control in all cases was obtained with the crude-oil emulsions. 
All the egg masses on apple shoots were destroyed by spraying with 10 per cent. 
Pennsylvania crude oil and Pennsylvania gas oil ; whereas figures closely com- 
parable with the checks were obtained by the use of a 10 per cent, and 1 5 per 
cent, emulsion of Western Shell distillate and several miscible oil washes used. 
G. W. G. 
Onion Smudge. By J. C. Walker (U.S.A. Jour. Agr. Res. xx. No. 9, 
Feb. 1 92 1, pp. 685-722 ; 6 plates). — Smudge is a common disease of onions, 
both in the field and in store. It is confined to the bulbs, and is characterized 
by black spots on the outer scales. It is most common on the white varieties 
of onions, and was ascribed to Vermicularia circinans Berkeley, but the author 
suggests that it should be termed Colletotrichum circinans (Berk.) Voglino, because 
of its subcuticular stroma and well-defined acervulus. Details are given of its 
characteristic growth on culture media and the conditions for germination of 
the conidia in the field. Control measures include protection of the harvested 
crop from rain, thorough and rapid curing, and well ventilated storage at 33* 
to 36 0 F. 
A short bibliography is appended. — A . B. 
Orchard-dusting versus Spraying. By N. J. Giddings (Journ. Econ. Entom. 
vol. xiv. pp. 225-238 ; April 192 1). — This paper is one of a series read at a 
joint meeting of the American Association of Economic Entomologists and 
the American Phytopathological Society to consider " dusting as a means of 
