217 



than by the borers. Manurial experiments are to be arranged to test 

 the effects of nitrogen, potash and phosphoric acid upon borer incidence, 

 and it is hoped that these will be continued over a series of years. It 

 is also intended to study gallery entrance healing in connection with 

 these experiments. 



The Drosophilid fly, Phortica xylehoriphaga. has been studied in 

 Its immature stages. Of 1,300 galleries examined on one estate, 

 6-8 per cent, contained some stage of the fly, and wherever they were 

 present dead borer larvae were found, but it is not definitely known 

 whether death was caused in every case by the fly, or whether the state 

 of decomposition in which the borers were invariably found had 

 attracted the fly to oviposit there. On one estate "a Trogositid, 

 Nemosoma ?, was present in such numbers as to exercise a vigorous 

 control over the borer. 



An experiment has been planned to try to discover some fertiliser 

 or insecticide that will have a deadly action upon borers in galleries 

 when buried with prunings. The possibility of destroying the ambrosia 

 fungus on which the borers subsist in the galleries is also being 

 considered. 



LouNSBURY (C. P.). Fumigation with Liquefied Hydrocyanic Acid.— 



Reprmt from S.A. Fruit Grower, June 1919, 2 pp. TReceived 

 1st March 1921.] 



The history of development of the use of Hquid hvdrocyanic acid 

 for orchard fumigation in California is reviewed [cf. "R.A.E., A, iv, 

 61 ; vii, 228 ; viii, 89]. Until additional means for dealing with'storage 

 and transport dangers are evolved, the liquid form cannot be used for 

 citrus orchards in South Africa under existing conditions. It may, 

 however, be used advantageously for the fumigation of buildings in the 

 larger towns. 



LouNSBURY (C. P.). Worms in Walnuts.— Reprint from S.A. Fruit 

 Grower, November 1919, 2 pp. [Received 1st March 1921.] 



In South Africa the codling moth [Cydia pomonella] is almost as 

 serious a pest of walnuts as of apples and pears. In parts of the 

 Oudtshoorn district the damage amounted to 50-60 per cent, of the 

 crop m 1914-15. The present conditions in California are reviewed 

 and remedial measures are advocated [R. A.E., A, vii, 359 ; viii, 238]. 



Other pests of walnuts in South Africa are Argvloploce leucotreta 

 (false codling moth), the ravages of Which may probably be prevented 

 by measures applicable to C. pomonella, and Myelois ceratoniae, 

 which has been recorded as living in seeds of Rohinia, carob {Ceratonia 

 stliqua) , a.nd chestnut {Castanea vesca) in Central and Southern Europe 

 This moth probably does not attack fresh fruit. 



Mally (C. W.). The Maize Stalk Borer, Busseola fusca. Fuller.— 

 Union S. Africa Dept. Agric, Pretoria, Bull. 3, November 1920, 

 111 pp., 31 figs., 4 plates, 1 chart. [Received 1st March 1921.] 



The object of this report is to record all available information on 

 Busseola fusca. Full, (maize stalk borer), and to serve as a basis for 

 further studies ; a list of the references consulted is therefore given 

 with a brief note in connection with each [cf. R. A . E., A, i, 144 ; v 35 • 

 vi, 153]. ■' > , , , 



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