614 The Oyster-Shell Bark Scale. [Jan., 



In 1905 the dry grain was given at fixed times, and any left 

 was removed after about three-quarters of an hour. The dry 

 mash, as explained above, was placed in the hoppers, so that 

 the fowls could help themselves. 



From these figures it will be seen that the increased cost of 

 food, due to its being of a more expensive nature by reason of 

 the large amount of meat consumed, is more than compensated 

 by the greater growth, at a lower cost for every pound increase 

 of weight. Hence it is apparent that the hopper system of 

 feeding and the use of dry mash are worth the attention of 

 poultry breeders and deserve a fair trial. Whether the food 

 supplied could not be cheapened remains to be tested. 



Edward Brown , 

 Will Brown. 



This scale insect (Asfiidiotus ostreczformis), whose shield 

 or covering bears, on occasion, a resemblance to an oyster 

 shell, is injurious in our country to 

 The Oyster-Shell various fruit trees. By draining away 

 Bark Scale. the sap the plant is weakened, and, where 

 the scales are in excess, killed. 



The insect belongs to the family Coccidce or scale insects, 

 and the sub-family Diasfiince. The characteristic of the 

 Diaspince is that the shield or scale covering the body of the 

 insect in various stages is composed partly of the insect's 

 moulted or cast skins and partly of matter secreted by the 

 insect. Aspidiotus ostreceformis infests apple, pear, plum, cherry 

 and allied rosaceous fruit trees ; it has also been found on 

 currant, and' Green and Newstead* record it on Calluna, 

 heather or ling. 



Description. — The following stages occur: egg, larva, 

 second stage of male and female, followed, in the female, by 

 the adult ; while in the male the second stage is followed by 

 a pupal stage which is succeeded by the adult. 



Female Scale or Shield. — On smooth bark where- not over- 

 crowded, the fully formed shield may have a diameter of 



* A monograph of the British Coccidce (Ray Society), by Newstead, vol. i, 

 p. 102. 



