PESTS AND DISEASES 81 



attacks permitted through neglect, destroying the flowers 

 also. Winter-flowering Carnations are best kept free from 

 green fly during the winter and spring months by occa- 

 sionally fumigating with tobacco-paper, or by means of 

 a vaporizer. The last-named is also suitable in the case 

 of Malmaisons, though perhaps no more effective aphicide 

 exists than ordinary tobacco-powder, dusted into the 

 growing points of the shoots, preferably at short intervals, 

 in order to prevent green fly gaining a footing ; but 

 if applied less regularly, no time should be lost, on the 

 discovery of aphis, in using tobacco-powder. In foliage, 

 even slightly affected, damage is clearly apparent, but 

 in cases where aphis has been permitted to live and 

 propagate, if only during a few days, much harm accrues, 

 the particular affection resulting having been called 

 Stigmanose. This pest is generally not much of an 

 affliction to Border Carnations, on which, if it should 

 appear, syringing with quassia extract will be found an 

 efficient remedy. Tits are so fond of aphis that, in 

 hunting for insects, they are apt to break the stems of 

 plants, hence though the insect itself is not destructive, the 

 birds undoubtedly are. 



Humble Bees. When these are numerous, the harm 

 they do is very great. In making a way to the base of 

 the bloom they twist and ravel the petals into all shapes, 

 and always split the calyx, leaving the bloom a mere 

 bunch of rags. They may be debarred from plants 

 grown under glass by closing all apertures with hexagon 

 netting. 



Maggot is productive of much loss unless watchfully 

 repressed. It is the larva of a fly Hylemia nigrescem^ 

 and attacks young plants, which the fly seems to select in 

 preference to older ones in which to deposit her eggs. 

 The attack cannot be prevented, because it is unsuspected 

 until the maggot has commenced operations under the 

 epidermis of a leaf, whence it finds its way into a shoot, 



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