11 
the error was excusable, because Dr. Eiley really had under obser- 
vation a closely allied species which could not, at that time, and from 
the literature at hand, be easily distinguished from the more com- 
mon Geresa bubalus. Dr. Riley has shown in a recent communication 
before the Entomological Society of Washington that his description, 
and figures of the eggs, relate to Ceresa taurina Fitch, a somewhat 
smaller and comparatively rare species. The general appearance of 
this latter insect is shown for purposes of comparison in the accom- 
panying illustration (Fig. 5, a, &), and the peculiar row of little raised 
egg-slits in the bark, each of which contains a single oval egg, are 
shown at Fig. 6, a, b. 
HABITS AND LIFE-HISTORY. 
The habits and life-history of the true buffalo tree-hopper are as fol- 
lows: The adult insect chooses as a nidus for its eggs the twigs, pref 
erably those of two or three years' growth, of various trees, particularly 
the apple, willow, cottonwood, maple, etc.; 
confines itself in general to the upper sur- 
face of the twigs, and works more abund- 
antly on the south side of the tree than on 
the north, although in this respect the pre- 
vailing winds and other conditions influ- 
ence the insect. The eggs are deposited 
quite as readily in the new growth of old 
trees as in young trees, but the damage is 
much more noticeable in the latter case. 
The eggs are placed in small compound 
groups arranged in two nearly parallel or 
slightly curved slits extending in the direc- 
tion of the twig about three- sixteenths of 
an inch in length, and separated by one- 
eighth inch or less of bark (Fig. 7, b). 
Facing either toward or away from the 
trunk, the female makes with its ovipositor 
a slightly curved slit through the outer bark, cutting in a direction pos- 
terior to the insect, so that the ovipositor, which is at first extended 
nearly at right angles to the body, at the completion of the slit, lies 
almost against the abdomen. The eggs are inserted very obliquely 
through the bai k and nearly at right angles to the twig, immediately 
after the completion of the pr. liminary incision, beginning at the end of 
the slit last made, and are thrust well down into the cambium layer 
between the bark and the wood (Fig. 7, c). A period of from one-half to 
two minutes is required for the insertion of each egg, after which the 
ovipositor is partly withdrawn, moved a little forward, and re-inserted, 
about twenty minutes being required for the cutting of the slit and filling 
it with eggs, which, in each slit, vary in numbers from 6 to 12. As soon as 
the first slit is completed a second one is made parallel to and slightly 
Fig. 6.— Ceresa taurina Fitch- a, 
twig showing rows of egg slits, 
natural size ; b, one egg slit enlarged, 
showing egg; c, larva; d, nymph- 
last two enlarged (copied f rom 
Riley). 
