481 



Weigel (C. a.) & DoucETTE (C. F.). Further Observations on the 

 Strawberry Root Worm on Roses. — //. Econ. Ent., Geneva, N.Y., 

 XV, no. 3, June 1922, pp. 204-209. 



The studies of the life-history and control of Typophorus [Paria) 

 canelhis, F. (strawberry root worm) as a pest of roses in greenhouses 

 [R.A.E., A, viii, 312; x, 218] have been continued. The adults 

 emerging in September and October apparently spend the winter 

 hiding in mulch or soil and feed on clear, sunny days. After February 

 they are frequently found on the plants and begin ovipositing towards 

 the end of the month. Oviposition is practically continuous through- 

 out the first eight months, the most marked periods being in March, 

 April, June and July. The eggs are laid in curled-up dead or dried 

 leaves, either singly or in masses up to 15. Each individual may lay 

 as many as 216. The incubation period varies from 7 to 27 days. 

 Upon hatching the larvae at once enter the soil, where they do con- 

 siderable injury to the roots of the plant. They require from 60 to 

 74 days to reach maturity. Pupation occurs in the soil and lasts 

 about 8 to 13 days. Most of the larvae and pupae are found directly 

 in the ball of the roots. There are at least two generations a year 

 under greenhouse conditions. 



The destruction of the larvae and pupae in the soil has been tried 

 with many substances, most of which proved useless either owing to 

 their effect on the plants or their ineffectiveness against the insect. The 

 best results were obtained with tobacco dust and wood ashes, and 

 further experiments are now being carried out with these substances 

 on a commercial scale. 



Arsenical sprays had previously proved unsatisfactory, owing to 

 the rapid growth produced by the forcing of the plants. When, 

 however, they were apphed at the rate of 4 to 5 lb. of powdered lead 

 arsenate or calcium arsenate to 50 U.S. gals, water, at the time that 

 the rose plants are cut back and the absence of foliage forces the 

 beetles to feed on the green bark and buds, they proved an effective 

 means of protecting the plants from injury during that critical stage. 

 A certain amount of success was also obtained with one part of powdered 

 lead arsenate to nine of superfine sulphur applied as a dust. The 

 successful use of hydrocyanic acid gas has now been proved on a 

 practical and commercial scale, and it was also found that muslin 

 curtains may be successfully used to confine the gas in any section of 

 an open range of houses. 



O'Kane (W. C). One Year o! the Crop Protection Institute.^//. 



Econ. Ent., Geneva, N. Y., xv, no. 3, June 1922, pp. 209-213. 



The first year's work of the Crop Protection Institute is briefly 

 reviewed. A conference was held at New York on the control of the 

 cotton boll- weevil [Anthonomus grandis, Boh.], and a concise statement 

 of rules relating to dusting against this pest was prepared. 



A co-operative dusting project in several States was successfully 

 carried out under the direction of the institute, which proved the 

 organisation to be an available means of bringing about profitable 

 and desirable co-operation among investigators. 



It has been supported by scientific workers, including members of 

 the Bureau of Entomology and of Plant Pathology, and although 

 the first year's work has been less extensive than was hoped, a sound 

 basis has been laid for future enterprise. 



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