SCALE-INSECTS. 27 



II. Neglecting entomological distinctions, we may divide 

 the Coccididae, roughly, into 



(a.) Insects attacking deciduous plants ; 



(b.) Insects attacking evergreen plants ; 

 or, again, 



(c.) Insects living usually on the bark ; 



(d.) Insects living usually on the leaves; 



(e.) Insects living on both bark and leaves ; 

 or, lastly, 



(/.) Insects covered with hard shields or "scales;" 



(g.) Insects covered with cotton; 



(h.) Insects naked. 



It will be clear that a different method will be required for 

 destroying these different classes ; but any one insect will belong 

 to more than one class. Thus Mytilaspis pomorum, the apple- 

 scale, belongs to (a), (c), and (/), and indeed may be placed 

 also in (b} } as such plants as hawthorns, which it attacks, are 

 as bad as evergreens in the difficulty of reaching the insect on 

 them; or, Lecanium hesperidum is in (a), (d), and (h) ; Lecanium 

 oka in (a), (b}, (e), and (K). 



As far as regards the injurious species of Coccids it may 

 usually be taken for granted that those infesting deciduous 

 plants (class a) live chiefly on the bark (class c), and are either 

 naked (class h) or covered with a hard scale (class /) . If naked 

 they are chiefly Lecanium ; if covered, either Mytilaspis, Aspidio- 

 tus, or Diaspis. 



leery a is exceptional, being omnivorous, feeding equally on 

 bark or leaves, deciduous or evergreen plants ; it belongs to 

 every class except (/) . Every method of destruction has therefore 

 to be resorted to against it. 



The treatment of a deciduous plant infested by Coccids is 

 simple as to its method. For two reasons the dead winter-time 

 must be chosen for it first, because, the leaves being off, the 

 whole plant can be easily got at ; secondly, because the eggs of 

 the insect have not yet been hatched, and the whole brood can 

 be destroyed at once. The first operation should be the pruning 

 of the tree, so as to reduce the labour required to a minimum. 

 A brushing over all the trunk and branches with a good hard 

 stiff brush and one of the liquid remedies given below is then 

 often successful. Brushing with a dry brush is adopted by 

 some persons ; but, although this doubtless clears away a good 



