Mussel Scale and Beetle Mites. 77 



Natural Enemies. 



Scales have many natural enemies, but this species and those 

 that attack the currant in this country are not materially lessened 

 by them. Anyone trusting to parasites to help the farmer in this 

 respect evidently is not acquainted with these pests in our orchards. 

 Amongst the natural enemies birds alone do any good. The Paridae 

 or Tits feed upon this scale, and a few other birds on the Tree- 

 creeper and Wryneck. Lady-birds and their larvae eat scale, but 

 none seem very partial to the Mussel scale in Great Britain. 

 Minute hymenoptera — Chalcididae — also live as parasites upon 

 them, but seldom do any appreciable good; in the first instance 

 they occur too late in the attack to prevent the damage, and never 

 are sufficiently abundant to check the pest for the following year. 

 Sound advice to fruit growers is to go on washing and ignore the 

 infinitesimal help given by these minute parasites. Also encourage 

 those useful birds the Tits in orchard and garden. 



Treatment. 



The trunks, etc., of all trees must be kept clean, i.e., free from 

 rough bark, moss and lichens. This can be done by washing in 

 winter with caustic alkali wash, which at the same time corrodes 

 and loosens the scales from the trees. Trees badly infested should 

 also be sprayed in the early summer about the middle of June with 

 paraffin emulsion, two or three times, at intervals of a few days. 

 This kills numbers of the young and corrodes away to some extent 

 any remaining scales. "VA^iitewashing the trunks of the trees as far 

 as the forks of the boughs does some good and keeps the wood in a 

 healthy state. All young stock should be treated to destroy the 

 scale before being planted or soon after. The best method is fumi- 

 gation with hydrocyanic acid gas, the most valuable scale remedy. 



Oribatidae or Beetle Mites on Forest and Fruit 



Trees. 



The Beetle Mites are frequently sent by fruit-growers with 

 enquuies as to their economy. The records of them on forest trees 

 are few. 



Specimens haA'e been sent from the Dii'ector, Royal Botanic 

 Gardens, and recei^'ed by him from Mr. A. S. Birknell, of Barcombe, 

 Sussex, which are recorded by him as damaging chestnut (horse) and 



