THE GRAPE LEAFHOPPER IN THE LAKE ERIE VALLEY. 
13 
newly transformed adult these yellow markings are hardly discerni- 
ble (fig. 8), the whole body being very light straw color. In a short 
time ; however, they become more pronounced. Along toward the 
middle of August the salmon color begins to appear, first as a light 
tint on the thorax and at the base of the elytra and in a short time 
extending to the tips of the wings. As the season advances the 
salmon color deepens until the insect takes on the more pronounced 
red markings of the wintering adult. 
THE EGG. 
The eggs of the grape leafhopper are not more than three-fourths 
of a millimeter long and are slightly curved (see fig. 10, d). They 
are semitransparent, with a yellowish tinge, and are very difficult 
to locate, since they are deposited beneath the 
epidermis of the underside of the grape leaf, which 
in most varieties is covered with a heavy pubes- 
cence. It is very difficult to detect them with 
the naked eye even after the most careful search. 
They may be located, however, with the aid of a 
hand lens or dissecting microscope by examining 
the underside of the leaf in bright sunlight. 
Under these conditions the eggs appear as slight 
shiny elevations under the epidermis. By care- 
fully scraping away the pubescence covering this 
area the outline of the egg maybe more plainly 
discerned. Figure 9 is an enlarged photograph 
showing the outlines of two eggs beneath the epi- 
dermis of a leaf of Concord grape. The eggs are 
extremely delicate and are very easily crushed 
when an attempt is made to remove the thin, 
semitransparent layer of leaf skin or epidermis 
underneath which they have been tucked by means of the slender 
ovipositor of the female (fig. 11). Figure 12 shows the anal segment 
of a male of the same species, with its genital armature. 
The eggs are usually deposited singly over the surface of the leaf, 
sometimes in or near the ribs and veins, but usually in the spaces 
between them. They do not appear to be placed in any regular 
order, but occasionally several may be found in close proximity. 
In one instance, in the leaf of a Clinton vine, three eggs were found 
quite close together with the long axis of all extending in the same 
general direction. Slingerland mentions finding the eggs laid from 
six to nine in a row in leaves of the Clinton grape. In this variety 
the leaf is less fleshy and has less pubescence than have the leaves 
of nearly all of the other varieties of grapes grown in the East. 
Examinations of the location and proximity of eggs in thin-leaved 
Fig. 8.— Adult grape leaf- 
hopper, summer form, 
showing the lighter shade 
of color markings of the 
elytra. Greatly enlarged. 
(Original.) 
