362 EXPERIMENT STATION RECORD. [Vol.43 



or hydrocyanic-acid jras, for a period of at least G we<'k.s. Tliis will kill all 

 the adults that einerfie during such a period and at the same time will prevent 

 the further laying (tf egfxs for future <j:enerations. The (losage need not be very 

 heavy in either case. When nicotin papers are used one sheet to every 1,000 

 cu. ft. of spjice will suffice. If liydrocyanic-acid yas is employed, 0.125 to 0.25 

 oz. per 1,000 cu. ft. will kill all of the adults. The use of hydrocyanic-acid 

 gas is not reconnnended unless in the hands of a competent fumigator, owing 

 to its deadl.v poisonous effi*cts. Too much empha.sis can not be laid on the 

 fact that the fumigation must be set off after 12 o'clock midnight, to be effec- 

 tive. It is preferable to start the generation between the hours of 12.30 a. m. 

 and 2 a. m. Any funiigaticai done before midnight would be useless, for it has 

 been pointed out that the adult d«es not emerge until after midnjght. On the 

 other hand, if it is started later than 2 a. m. many aduls will have emerged 

 and laid their eggs." Where fumigation is not advisable, spraying con.sistently 

 for a. period of 4 to 6 weeks, with a solution of 40 per cent nicotin sulphate 

 extract diluted (1:800), and soap added at the rate of 0.5 to 1 oz. per gal. of 

 solution is recommended. 



The authors emphasize the Importance of preventing any but clean plants 

 and cuttings from being brought into conunerciul greenhouses where chrysan- 

 thenuims are gi'owing or to l)e grown. 



An annotated list of 32 references to the literature is included. 



The stable fly: How to prevent its annoyance and its losses to live stock, 

 F. C. BiSHOPP {U. S. Dcpt. Afn:, Fanners' BiiL 1097 (1920), pp. 21, fiyft. 11).— < 

 This is a revision of Farmers' Bulletin 540, previously noted (E. S. K., 29, p. 

 559). 



The green Japanese beetle problem, J. J. Davis {.lour. Econ. Ent., IS 

 {192-0), No. 21, pp. lS5-19Jf). — This is a brief and concise resume of the green 

 Japanese beetle {FopiUia jnponica Newm.) problem, including its present status 

 and plans for future work. 



The green Japanese beetle quarantine, C. H. Haui.ey {.Jour. Econ. Ent., 

 1.3 {1920), No. 2, pp. 198-201). — This is a discussion of the quarantine work with 

 Popillia iaponiciu 



The strawberry rootworni injuring roses in greenhouses, C. A. Weigeli 

 and E. L. Chambers {.Jovr. Econ. Ent., 13 {1920), No. 2, pp. ;226-2.:?2).— Reports- 

 of injury to roses in greenhouses at Alexandria, Va., and Richmond, Ind., led to 

 the investigation here reported. It was found at Alexandria on .July 25 that 

 the damage was caused mainly by the adults of Farla cunceUns Fab., which were 

 present in extremely large numbers, i)ractically all the foliage being badly per- 

 forated and ragged. 



" In addition, a large proportion of the new and young shoots had the wood 

 badly scarred and girdled, giving it a very imsightly appearance. It was 

 found that tJie adults had a marked preference for this new wood, of which 

 there was an abiindance at this particular part of the season, owing to the fact 

 that the roses Avere being forced. Further examination showed that the larvte 

 had also been feeding on the roots earlier in the season. As a resxdt of all 

 of these injui'ies a gradual killing of the affected parts ensued, causing a 

 stunted growth of the plants." 



The infestation at Ilichmcmd was not as serious as that at Alexandria. It 

 has since been found to occur in greenhouses in Washington, D. C, Summit, 

 N. J., and Baltimore, Md. Experimental control work has shown that the use of 

 hydrocyanic acid gas, at the rate of 2 oz. sodium cyanid per 1,000 cu. ft. of 

 space, with an exposure of 2 hours, is a satisfactory method of controlling the 

 adults. 



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