42 
covered with a short, flocculent secretion, giving them the appearance 
of mealy bugs, and measure about 1.8"" in length by about 1™™ in 
diameter. The front of the head is straight, the tail knob-like, the 
last segment deeply bilobed and provided with bristles and minute 
spines as in the migratory form. The antennee are also five-jointed, 
though only about half as long as those of the migrant. The two 
basal joints, as usual, are short and stout, each bearing a bristle; the 
last is somewhat the longest; the third and fourth slightly shorter, 
subequal in length, and allthree slightly annulated. In other respects 
they resemble the previous stages. 
Sixth, or sexual generation.—From early in June till about the mid- 
dle of the month the migratory generation, bred on the birches, 
attains its full development and migrates back to the witch-hazel to 
consign to it the final or sexed generation. Large numbers of these 
migrants may then frequently be seen on the under side of the leaves 
of this shrub, in the 
neighborhood of the 
birehes, and with 
them numerous lar- 
vee, scattered over the 
surface of the leaves, 
particularly along the 
midrib and the veins. 
On one of the leaves 
examined 61. living 
and 20 dead larvee 
were counted, and on 
FiG. 22. —Hamamelistes spinosus: a, young larva, sixth or sexual another leaf 35 living 
generation, dorsal view; b, denuded, showing arrangement of ob Eos is = 
pores; c, tarsus; 7, lateral tubercle and waxy rod; e, apex of and a considerable 
lateral tubercle—much enlarged (original). number of dead lar- 
vee, which tends to in- 
dicate that only about one-third, or even a smaller percentage of all the 
larve, are able to reach maturity, and that even a much smaller 
number of the winter eggs may surviveand hateh the following spring. 
The sexual generation develops also rather rapidly and reaches matur- 
ity within two or three weeks, when, toward the middle or end of 
June, after copulation has taken place, the females forsake the 
leaves and betake themselves to the twigs for the purpose of deposit- 
ing their winter eggs in the immediate neighborhood of the dormant 
flower buds, which, in the spring following, start to develop just at 
the time that the eggs are hatching. 
Sixth generation, first stage (Fig. 22).—The young larve of the 
sexual generation are of a very pale yellowish-white color, with the 
eyes black and minute. They are about 0.5" long, oval or slightly 
broadest across the thorax. There are generally about twelve short 
and stout secretory tubercles along the front of the head, two or three 
in front of the eyes, and two near the posterior margin between the 
