No. 4, February, 1922] PATHOLOGY 291 



1S95. GiDDiNGS, N. J. Orchard dusting versus spraying. Jour. Econ. Entomol. 14: 225- 

 230. 1921. — Sulphur dust for control of peach scab (Cladosporium carpophilum) in West 

 Virginia averaged a little better than liquid sprays. Brown rot {Sclerotinia cinerea) data 

 are inadequate because of light infection. Foliage injury resulted only when excessive 

 amounts of material were used. Comparison of copper-lime and sulphur dusts with Bordeaux 

 and lime-sulphur si)rays for control of apple scab {Ventaria pomi) showed that dusts are not 

 so effective as spraj's where the disease is severe. The author believes that for rapid progress 

 of dusting the "cooperation of chemistry, physiology, entomology, and horticulture" is 

 necessary, and that negative evidence as well as positive data should be published in order 

 that commercial orchardists may not be unduly influenced and suffer extreme losses. [See 

 also Bot. Absts. 10, Entries 1896, 1897, 1899.]— J. E. Kotila. 



1896. Headlee, T. J. Dusting as a means of controlling injurious insects. Jour. Econ. 

 Entomol. 14: 214-220. 1921. — In 3 years' experimentation sulpho-arsenical lime dusts 

 were found practically as effective as self-boiled lime-sulphur and lead arsenate applied as 

 liquid spray for control of insects and diseases of peach. For control of insects and diseases 

 of apple in New Jersey, dusts were not found equivalent in any way to liquid sprays. Experi- 

 ments in 1920 showed that 90-10 dust impregnated with 1 per cent nicotine is as effective as 

 dust with 3 per cent nicotine, and only a little more than 5 as effective as liquid treatment 

 (f pint nicotine to 50 gallons) for control of leafhopper. "Although recently hatched aphids 

 were more efficiently killed by liquid treatments, 90-10 dust impregnated with 1 per cent or 

 more of nicotine caused very material execution." [See also Bot. Absts. 10, Entries 1895, 

 1897, 1899.]—/. E. Kotila. 



1897. Parrott, p. J. Control of sucking insects with dusting mixtures. Jour. Econ. 

 Entomol. 14: 206-214. 1921. — Redbugs were found to be very sensitive to nicotine dusts. 

 No difference was found between 0.5 and 1 per cent nicotine dusts. For apple and currant 

 aphis, dusting compared quite favorably with liquid sprays. Mixtures carrying less than 

 2 per cent nicotine gave very poor control of potato aphis. Nymphs of apple leafhopper were 

 very susceptible to dusts containing 0.5 and 1 per cent nicotine, and 80 per cent of nymphs of 

 the grape leafhopper were destroyed by dehydrated copper-sulphate and lime containing 

 2 per cent nicotine. Four-lined plant bug nymphs were much more resistant than apple 

 redbug, but dusts with 2 per cent nicotine caused complete paralysis. The degree of suscepti- 

 bility varied with different species. Density of foliage was found to be a greater factor in 

 obtaining control by dusting than was the case with spraying. [See also Bot. Absts. 10, 

 Entries 1895, 1896, 1899.]— J". E. Kotila. 



1898. PuiG, Jtjan. Los parasites vegetales y animales de las plantas cultivadas y espon- 

 taneas observados en la Republica Oriental del Uruguay. [Animal and vegetable parasites of 

 cultivated and native plants in Uruguay.] Inspecci6n Nacion. Ganaderia y Agric. [Uruguay] 

 Bol. 36. 19J^ p., 52 fig. 1919. — General directions are given for the control of the more im- 

 portant insect pests and diseases of the crop plants of Uruguay. A list of insects and plant 

 diseases collected by the author is included. — John A. Stevenson. 



1899. QuAiNTANCE, A. L. Dusting versus spraying of apples. Jour. Econ. Entomol. 14: 

 220-225. 1921. — Data obtained in Michigan, Virginia, Arkansas, Connecticut, and Colorado 

 are tabulated. In northern states where codling moth is not especially severe, dusting con- 

 trols the insect practicall}^ as well as spraying. Further south dusting is not a satisfactorj' 

 control measure. In arid regions, as in Colorado, dusting is notably less effective than spray- 

 ing. Dusting compared favorably with sprajang in control of plum curculio on apple where 

 the insect was not especially abundant. [See also Bot. Absts. 10, Entries 1895, 1890, 1897.] — 

 J. E. Kotila. 



1900. RiTZEMA Bos. J. Bestrijding van de zoogenaamde "witte roast" der schorzeneeren, 

 veroorzaakt door Cystopus tragopogonis (Persoon) Schroet. [Combating the so-called "white 

 rust" of salsify caused by Cystopus tragopogonis.] Tijdschr. Plantenz. 26: 216-220. 1920. — 

 Following a brief description of the pathogene and its habits, the author presents the experi- 



