1907.] Orchard and Bush Fruit Pests. 717 



Oyster-shell Bark Louse. — Plum trees were found badly 

 attacked by the oyster-shell bark louse {Aspidiotus ostrcee- 

 fonnis) near Ross, in Herefordshire ; and near Ombersley, in 

 Worcestershire. In both cases the trees were cut down and 

 burnt, as they were smothered with the scales and dying. It 

 also occurs in Kent fruit plantations. Mr. F. Smith recently 

 informed me that it is found here and there in the Maidstone 

 area. Another grower sent the same insect, which was cover- 

 ing plum trees near Sittingbourne. Although it does not 

 spread very rapidly, it soon covers a tree it once settles upon, 

 and the fate of the tree is then assured, unless it is treated with 

 paraffin emulsion in winter. 



Mussel Scale. — By far the worst scale insect on fruit trees is 

 the mussel scale {Mytilaspis pomoruni), which has been sent to 

 me no less than fifty times during the past summer. It has un- 

 doubtedly increased enormously during the last four years, and 

 may be found in all parts of Great Britain. One young tree 

 was seen in Worcestershire in which it was almost impossible 

 to find a piece of the bark, so thickly had the " scales " en- 

 crusted it. Needless to say the tree was dead. One note has 

 been sent me saying that Chalcid parasites had materially 

 checked it, but in the majority of specimens sent no sign of 

 these insects could be found. So far, the only treatment seems 

 a heavy spraying with strong paraffin emulsion or with Mr. 

 Spencer Pickering's wash of paraffin with caustic soda in winter 

 or dilute paraffin emulsion when the eggs are hatching out in 

 June. Mr. Collinge wrote me in June last that he was destroy- 

 ing it in millions with caustic alkali wash. In Kent, and also 

 at Woburn, this was found to have no effect ; thus showing 

 how different washes have diverse effects in separate localities. 



A Shield Bug on Cherry. — From St. Ives, Huntingdonshire, 

 the large shield-bug [Tropicoris rufipes) was reported as occur- 

 ring in large numbers on cherry trees, and causing damage. 

 This common bug has not before been noticed as a fruit tree 

 enemy. 



Big Bud Mite. — The big bud mite {Eriophyes ribzs) has, as 

 usual, been very harmful, but by persistent hand picking in 

 December and January it has been kept in check in many 

 plantations and I have seen them quite cleaned by this method. 



