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Of spray fluids for the destruction of Eed Spiders, sulphur 

 compounds or paraffin emulsion are those usually recom- 

 mended. From the former class, potassium sulphide is the 

 standard insecticide but in the case of gooseberries lime- 

 sulphur would seem to answer the same purpose, and can 

 be used simultaneously against Red Spider and American 

 Gooseberry Mildew. Paraffin emulsion compounds have fallen 

 to some extent out of favour, probably owing to occasional 

 foliage injury. Paraffin jelly has, however, been found very 

 effective by Theobald* (Wye Agricultural College). 



In the case of the Greenhouse Red Spiders which make 

 thick webs, special precautions have to be taken to ensure 

 proper wetting and Lloydf (Waltham Cross Experiment Station) 

 states that he finds flour paste very effective for the purpose, 

 having the advantage of causing no hardening of the foliage 

 in cucumbers, a marked defect in the case of solutions con- 

 taining soap. Flour paste has also been used for the control 

 of Red Spider in the U.S.A. even without the addition of a 

 sulphur compound, and it is probable that the addition of it 

 to all sulphur washes would be beneficial, even when they are 

 required for outdoor use. Formulae for preparing the various 

 washes are given below with the exception of lime-sulphur 

 which is fullv described in Leaflet No. 195 J on American 

 Gooseberry Mildew. 



FORMULA. 



fa) Potassium Sulphide (Liver of Sulphur) Wash. (Original 

 Formula.) 



Potassium sulphide ... ... 5 oz. - 



Soft soap ... ... ... $ lb. 



Water 10 gall. 



In preparation the soap and potassium sulphide are dissolved 

 in the water. 



(b) Potassium Sulphide (Liver of Sulphur) Wash. (Lloyd's 

 Formula.) 



Potassium sulphide ... .. 1 oz. 



Flour ' H oz - 



Water 2 gall. 



" Place 14 pints of water in a bucket and add 1 oz. liver 

 of sulphur which will completely dissolve while the flour paste 

 is being prepared. Make 1 oz. ordinary wheat flour into * 

 smooth paste with a very little water. Add water to 2 pints 



* Insect Pests of Fruit. F. V. Theobald. 



f Circular (Vol. 1. No. 6) Lea Valley and Bist. Nurserymen & 



Obtainable from the Ministry and also included in Sectional Volume 

 No. 1, price 8d. 



