73 
(No. 8), leaving- out the tobacco; or strong soap 
suds may be applied with effect. The application 
should be done by the engine, with force to break 
the web or filmn, when the sun is not powerful, 
lest it should injure the leaves. 
CHERRY TREE. 
Black Leaf Louse, (Aphis .) — This spe- 
cies of the Aphides generally commences its 
ravages about the latter end of April or beginning 
of May. It is of a middle size in comparison to 
the I’est of its genus, plump bodied, and com- 
pletely black. In its perfect state it is supplied 
with wings, which aid it to emigrate into different 
parts. It establishes its progeny at all times 
viviparously, and, if possible, breeds more nu- 
merously than any of the species already de- 
scribed. A general emigration takes place about 
the middle of June, when the trees become re- 
leased from these ravenous and unparalleled pests. 
Those trees, which are first infested at the spring, 
arc possessed by emigrants that arrive in the 
month of September, from where I cannot tell, 
probably from field or gai'den productions, for it 
is remarkable that the Cherry tree is not possessed 
by them from the middle of June to the fore end 
or middle of September. At the latter period it 
again becomes the choice of this insect, in its 
perfect or winged state, to establish her progeny, 
F 
