758 



The Felted Beech Coccus. [march, 



or, inadvertently, by birds and insects, and this is undoubtedly 

 the means by which fresh colonies are started. 



The male is unknown in any stage, the females being 

 parthenogenitic, and can evidently reproduce their species 

 without the intervention of the opposite sex. 



Many of our indigenous Scale insects are subject to the 

 attacks of minute parasitic insects related to the wasp family ; 

 but, so far, the beech coccus has proved immune from their 

 attacks. Birds, moreover, do not appear to feed upon them. 



Treatment. 



Owing to the comparatively smooth nature of the bark of the 

 beech, and also to the fact that the insects are often confined to 

 the trunk and main branches, this pest is thereby rendered more 

 easily accessible for treatment with insecticides than are many 

 other pests. But they are so well protected by their waxy 

 coverings that the application of an insecticide must be carried 

 out in a thorough manner or the result will be anything but 

 satisfactory. The three formulas given below have proved 

 to be thoroughly efficient in destroying this pest, and if applied 

 according to the instructions will be found to give highly satis- 

 factory results : — 



1. Paraffin Emulsion. — This should be prepared in the 

 following way : — Mix equal proportions of soft soap, dissolved 

 in boiling water, and paraffin, and then churn them up by means 

 of a force-pump or syringe. When required for use add twenty 

 times its bulk of water and again churn with a force-pump 

 or syringe. 



2. Paiaffin Emulsion with Sulphur and Turpentine added."' — 

 Take about half a gallon of soft water, boil and dissolve about 

 I lb. of common soap, add a handful of sulphur and a pint of 

 paraffin, and about the same quantity of turpentine. Then add 

 about four gallons of soft wa f er to this mixture. Churn well 

 together, as recommended in the previous formula. 



3. Caustic Alkali Wash.] — Dissolve 1 lb. of cemmercial 

 caustic soda in water, then 1 lb. of crude potash or pearl ash 

 in water. When both have been dissolved mix the two well 



* Gillander's Mixture: Trans. Manchester Microscopical Soc, 1898. Separate 

 reprint, p. 12. 



t See also Leaflet No. 70. 



