114 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



agents have been employed, but none successfully without more 

 or less injuring the bark and roots, ultimately destroying the 

 tree itself. 



A knowledge of what the insect really is, and how it performs 

 its destructive function, will probably interest and enable the 

 student to battle with the enemy more thoroughly than were he 

 working in the dark. 



American blight — Eriosoma lanigcra, E.mali, or Aphis lani- 

 gcra — is comparatively of recent establishment in this country, 

 and is explained by Johnson as being abdomenless and without 

 tubercles, antenna?, or horns, the males having wings, but the 

 females none. It was thought at one time that the russet class 

 of Apple was exempt from its ravages, but this is a great error, 

 as some of the worst cases have been of that particular class. 



Examined under the microscope, it will be found that the 

 male has no true antennae, but the two foremost legs are armed 

 with very sharp penetrating sickle-like terminations, which cut 

 into and through the bark and wood of the tree attacked, it 

 being remarkable the great power these little creatures possess 

 in cutting down into the sap-cells, and thrusting the proboscis 

 into the wound. When disturbed, they hold on by burying 

 these sharp extremities into the tissue of the stem, and will 

 submit to be torn to atoms rather than relinquish their hold. 



The wings are not large. In the female they are said to be 

 absent, but this is not the case. The soft white cottony sur- 

 rounding of these pests is formed partly from a desquamation 

 that seems to be perpetually going on, and a gelatinous ex- 

 crescence which holds it more or less together. In this medium 

 the female lays most of her eggs, and in dry weather, from its 

 extreme lightness, it gets detached and scattered by the wind, 

 attaching itself to the trees that lie in its way, or it falls on the 

 ground, there to germinate. In the winter the larvae attack the 

 .roots in a similar way to that of their parents on the upper part 

 of the tree. About the end of February great activity commences 

 amongst the colony under the soil to establish its summer 

 quarters above, and it is at this time that the attack is easiest, 

 and the enemy least organised and weakest. At this time the 

 larva' and pupae ascend the main trunk to their chosen quarters. 

 Before commencing they lie about on the surface of the earth, 

 or immediately below it, to germinate and revivify. Many 



