PILANT LICE. 197 
leaves, petioles, and between the folds of young leaves. ‘With 
them was found a winter egg in January, deposited in an angle 
formed of the midrib and a vein on the under side of the leaf.’ 
On most of the plants that remain green or partially green dur- 
ing the winter, the ordinary viviparous form of the insect has 
been found throughout the season. On plants that die down 
completely in fall it-has, of course, been found during the summer 
months only, and usually beginning with the month of June or 
July. It is probable, therefore, that the insect winters, not only 
in the egg state, but also in the incomplete wingless form. It is 
of course, certain, that a large proportion of these hibernating 
forms are killed off in one way or another; but under ordinary 
circumstances, a considerable proportion of them survive. The 
hardest winters for them are those in which frosts and thaws 
alternate frequently. In New Jersey, where the insect is trouble- 
some to melons,. it is certain that the insect winters on the com- 
mon weeds of the fields along the road sides, and probably also 
to some extent in strawberry patches, where such are planted 
in ‘the vicinity of melon fields. Among the long list of common 
weeds on which the insect has been found, there is no difficulty 
in finding a sufficient number of plants for the specimens com- 
pelled to leave the dying cucurbits in the fall. As soon as warm 
weather arrives in spring, the insects begin to multiply; slowly 
at first, more rapidly as the season advances, if the weather proves 
favorable. Experience has shown that in New Jersey the ques- 
tion of whether we will have-an invasion of the insects, is set- 
tled during the month of June. If the weather during this month 
is favorable for the development of plant lice, i. e., warm and 
pleasant, without cold storms, they increase rapidly, and by the 
middle or towards the end of June, depending a little upon loca- 
tion and earliness of the season. the insects begin to crowd the 
plants upon which they have theretofore lived, and winged in- 
dividuals are developed. These fly from their original food 
plants, and if melon vines are in the vicinity, they settle upon 
them and at once start reproduction. We may find, usually dur- 
ing the latter part of June or early in July, scattered here and 
there on the vines, a winged viviparous female, with a cluster of 
anywhere from four to ten or a dozen wingless young of differing 
sizes about her; or we may find a little cluster without the winged 
