49 



The facts are somewhat suggestive of the presence of two 

 distinct forms, and it is important from the practical point of 

 view that the matter should be decided. If there is only u 

 single species, then the grower who wishes to clear his orchard 

 should treat any surrounding hawthorn hedges a.s well as hit? 

 apples. If, on the other hand, there are two species, a severe 

 infestation on the hedges need not necessarily be regarded us 

 a danger to the apples. 



The Euonymus-feeder in its life-history does not differ widely 

 from that just described, but the insect is quit-e distinct, and 

 indeed never feeds on either apple or hawthorn. The moths 

 always have pure white fore wings with very conspicuous 

 black spots, and are somewhat larger than those of the apple- 

 feeding species. 



Natural Enemies. Ermine Moths are attacked by a 

 number of species of Ichneumon Fly, such as Angitia majalis 

 Grav., and Herpestomus brunneicornis Grav., the larvae of 

 which feed inside the Ermine caterpillars. They are also 

 devoured by starlings and probably by other birds. 



Methods of Control. 1. The most satisfactory treatment 

 is to spray the affected trees or hedges with lead arsenate (1 Ib. 

 lead arsenate paste in 20 gallons of water) soon after the 

 blossom is over. The object is to cover the leaves with a fine 

 spray of lead arsenate which will sooner or later be eaten 

 by the caterpillars, and will poison them. It is useless to 

 wait until serious damage is apparent, for then not only has 

 considerable loss of fruit and foliage already occurred, but 

 also the dense web prevents the spray from reaching those 

 leaves which are left. Provided the webs are small, however, 

 and there is much clean foliage, it is still worth applying the. 

 spray, in order to prevent further injury. It is not certain 

 how early the spraying can be done, but it is probable thai/ 

 many of the caterpillars will be destroyed even if the lead 

 arsenate is put on just before the blossom opens. In no 

 circumstances should the spray be applied to open blossoms. 



Lead arsenate is poisonous to man, and must therefore.be 

 used with care. 



2. It is possible though it does not appear to have been 

 proved that a winter wash would destroy the young larvae 

 under the egg scales. In addition to the caustic washes given 

 in the Ministry's Leaflet No. 70 (The Renovation of Neglected 

 Orchards), paraffin emulsions and miscible oils are worth a 

 trial. Miscible oils must be bought from a manufacturer, and 

 be diluted in accordance with his instructions. 



A paraffin emulsion for winter use may be made as 

 follows : 



Paraffin 1 gallon. 



Soft soap H-21b. 



Water 10 gallons. 



