19:;o] ECONOMIC ZOOLOGY — ENTOMOLOGY. 451 



and 37 species described as new. Psylla isitis Buckton is a pest on Indigo and 

 Euvhulcrus citri (Kuwayaiiia) on citrus trees. 



rotate sprayinj; <'\perinu'nts on the control of the pink and green aphid 

 (Macrosiphuni sohinilolii Ashniead), I'art I, L. li. Smith (Virf/inia Truck 

 Sta. Bui 29 UOnj), pp. 101-11^, fly. i).— This is a report of control work with 

 the pink and green aphid begun in 1915 and conducted each year since that 

 time. An account of tliis ix\st by the autlior lias previously been noted (E. S. R., 

 41. p. GG2). 



"The losses from this i?isect have been in the past more severe on the Eastern 

 Shore peninsula than in the Norfolk section. Much of the data herein recorded 

 Is based on experiments conducttYl in 1917. 



" The spring crop of potatoes are usually infested within 2 or 3 weeks after 

 they come through the ground. The effect of the aphids feediiig is first notice- 

 able as a curling of the leaves, which is later followed by their turning yellow 

 and dropping to the ground. The infested areas within a field are easily dis- 

 tinguishable by the yellow and withered appearance of the plants. The effect 

 of the injuries when the plants are not killed is to delay the development of the 

 tubers. 



" Nicotln sulphate and fish oil soap were the materials used to combat the 

 aphids. . . . Nicotin sulphate was also u.sod in combination with Bordeaux 

 mixture and arsenicals. . . . The formula recommended is as follows : Nicotin 

 sulphate, 8J oz. ; fish oil soap, 5 lbs. ; and water, 50 gal. 



'• If it is desired to use a combination spray, add 8 to 10 oz. of nicotin sul- 

 phate to the 50 gal. of mixture as prepared for use against tiie potato beetle. 

 Do not mix the nicotin in the same spray with Paris green. When the Bordeaux- 

 nlcotin combination is used, two or more sprayings should be made about 8 to 

 10 days apart, and the first one to come when the plants are 5 or 6 weeks old. 

 Sprayings with the nicotin and .soap may be withheld somewhat longer but in 

 no case until serious injury has resulted to the i)lants. It is better to spray too 

 early than too late. If the first application does not entirely destroy the aphids, 

 a second application must be made one week later. 



" The governing factor of the results obtained in spraying for the control of 

 plant lice is the thoroughness of application. No benefits are derived unless a 

 large proportion of the insicts are directly hit by the spray. To accomplish 

 this purpose, it is essential that the machinery is suitable and in the best po.ssible 

 mei'hanical condition I)y the time the spraying season commences. A hard 

 driving spray is best for use against these in.sects on potatoes, and a machine 

 which will develop and maintain at least 150 and preferably 200 lbs. is the mo.st 

 economical to use." 



Sugar-beet root-louse control, D. Hansen (U. S. Dcpt. Agr., Dcpt. Cirv. 

 86 {VJ20), pp. 16, 11). — This is a brief report of work with the sugar-beet 

 louse, conducted in cooperation with the Montana Exiteriment Station, and is 

 in c(tntinuation of that previously noted (E. S. R., 39, p. 863). In the work in 

 191.S, 10 plats in the field u.sed in 1916, 1917, were irrigated 2. 3, 4, and 5 times, 

 resijectively. The results, which are reported in tabular form, indicate that the 

 amount of infestation on any of the plats, regardless of the number of irriga- 

 tions, was very small and perhaps not sufiicient in any case to affect the yield. 

 This was the case also in other fields that were observed, and was apparently 

 due to climatic conditions that at some time during the sea.son were unfavorable 

 for the development of the root lou.se.* 



Spraying walnut aphis, E. Braunton {Cal. Cult., 5Jf (1920), No. 20, p. 812, 

 ft0- i)^^The nicotin dust spray is said to have proved quite effective during 

 1919 against the green apple aphis, melon aphis, peach thrips, and onion thrips, 

 as well as against the walnut aphis. 



