Scale on Pineapples and Pine Beetle. 135 



water and the larger the lumps of cyanide used the slower the gas 

 comes off. 



Experiments conducted by Mr. Cousins in England show that the 

 following quantities are required per cubic foot of space — 3 ozs. of 

 cyanide, 5 ozs. of acid, 8 ozs. of water per 1000 cubic feet. Both the 

 cyanide and the gas generated are poisons. 



If gas treatment cannot be carried out owing to lack of material 

 or apparatus, then spraying should be employed. 



Scale on Pineapples. 



{Dias-pis hromdicc, Kerner.) 



Pineapples are frequently damaged by a scale insect, which now 

 and then causes the fruit to rot. Specimens have been sent by Mr. 

 Hammond, of Kingston, Jamaica, for identification and information 

 concerning it. This scale is the Pineapple Scale (Diaspis Iromelite, 

 Kerner). The scale is tliin, circular and pure white — the females 

 yellow or orange. Like most Diaspids, they burrow beneath the 

 epidermis of the plants and become almost entirely hidden. 



It chiefly attacks the leaves, but now and then the fruit. 



It should be destroyed as soon as the fruit is cut. 



SUB-GROUP B. 



Section III. 

 Animals Injurious to Forestry. 



The Pine Beetle. 



{Hylesinus pinipei^da, Linn.) 



Some pine wood sent by R. E. Haslam, Esq., from Monico, was 

 found to be attacked by the Pine Beetle {Hylesinus piniperda, Linn.) 

 It had killed an old tree and two young ones. This insect chiefly 

 attacks diseased and damaged timber ; but if no unhealthy trees are 

 about it will attack healthy ones. As a rule one sees this pest 

 working in plantations of about thirty years standing. 

 <> Sootch and Weymouth Pines are chiefly attacked, but cluster and 

 other species of pines are frequently recorded as being damaged by 

 this pest. 



This insect does harm in three ways ; (i) the beetles and larvse 

 attack ])ark and bast, the former making longitudinal galleries with 



