BLIGHT. 
236 
a very feeble insect. We call it, from habit, or from 
some unassigned cause, the “American blight” (aphis 
lanata); this noxious creature being known in some 
orchards by the more significant name of “white blight.” 
In the spring of the year a slight hoariness is observed 
upon the branches of certain species of our orchard 
fruit. As the season advances this hoariness increases, 
it becomes cottony, and toward the middle or the end 
of summer the under sides of some of the branches 
are invested with a thick, downy substance, so long as 
at times to be sensibly agitated by the air. Upon ex- 
amining this substance we find, that it conceals a multi- 
tude of small wingless creatures, which are busily em- 
ployed in preying upon the limb of the tree beneath. 
This they are well enabled to do, by means of a beak 
terminating in a fine bristle : this, being insinuated 
through the bark, and the sappy part of the wood, 
enables the creature to extract, as with a syringe, the 
sweet, vital liquor that circulates in the plant. This 
terminating bristle is not observed in every individual : 
in those that possess it, it is of different lengths, and is 
usually, when not in use, so closely concealed under 
the breast of the animal, as to be invisible. I ft the 
younger insects it is often manifested by protruding 
like a fine termination to the anus; but as their bodies 
become lengthened the bristle is not in this way observ- 
able. The alburnum, or sap wood, being thus wounded, 
rises up in excrescences and nodes all over the branch, 
and deforms it; the limb, deprived of its nutriment, 
grows sickly ; the leaves turn yellow, and the part 
perishes. Branch after branch is thus assailed until they 
all become leafless, and the tree dies. 
Aphides in general attack the young and softer parts 
of plants ; but this insect seems easily to wound the 
harder bark of the apple, and by no means makes choice 
of the most tender part of the branch. They give a 
preference to certain sorts, but not always the most rich 
fruits ; as cider apples, and wildings, are greatly infest- 
ed by them, and from some unknown cause other varie- 
ties seem to be exempted from their depredations. The 
Wheeler’s russet, and Crofton pippin, I have never ob- 
