4 
The winged females appear somewhat abundantly in antumn, and are 
one of the means of the dispersal of the insect. They are very minute, 
clear-winged, gnat-like objects, greenish-brown, almost black in color, 
with the body covered with more or less of the cottony excretion. 
The aerial colonies are probably killed out every winter in the colder 
northern districts, but in the warmer latitudes the partly grown indi- 
viduals, at least, survive protected in crevices or under bits of bark, 
and remain more or less active during winter and renew the colonies 
the following spring. This has been shown to be true in the District 
of Columbia, and also in the interior regions of the same latitude in 
spite of the much colder winters. The root form survives the winter 
usually in an immature condition, viz, larve in various stages of devel- 
opment; and both in latitudes where the aerial forms are killed by the 
severity of the winter and elsewhere it seems probable that there is a 
regular upward migration in spring and early summer from the roots, 
the aerial colonies appearing first near the crown and at a later period 
on the higher parts of the trees. At any time during the summer and 
fall there may be migrations to the roots, and throughout the year the 
subterranean colonies are maintained. 
The spread cf the insect is accomplished in part by the viviparous 
females, which appear in late summer, but quite as commonly perhaps 
by the transporting of young or partly grown individuals from tree to 
tree or to distant orchards by means of birds or insects to which they 
have attached themselves. Its wide distribution is usually dependent 
on the traffic in nursery stock. 
REMEDIES AND PREVENTIVES. 
The foregoing account of the habits and characteristics of the woolly 
aphis will enable us to suggest certain measures to control it. The 
aerial form presents no especial difficulty, and can be very readily exter- 
minated by the use of any of the washes recommended for plant-lice, 
such as kerosene emulsion, a strong soap wash, resin wash, ete., the 
only care necessary being to see that the wash is put on with sufficient 
force and thoroughness to penetrate the covering and protecting cot- 
tony excretion. If the wash be applied warm, its penetration will be 
considerably increased. 
The much more important root form, however, is more difficult to 
reach and exterminate. Any of the remedies which are applicable to 
the phylloxera will apply to the apple-root plant-louse, such as the use 
of bisulphide of carbon or submersion. The common recommendations 
are of applications of strong soap or tobacco washes to the soil about 
the crown, or soot, ashes, or tobacco dust buried about the roots; also 
similarly employed are lime and gas-lime. 
The most generally recommended measure hitherto is the use of hot 
water, and this, while being both simple and inexpensive, is thoroughly 
