TREE-HOPPERS. 109 
drawn, 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 six to 
twelve. As soon as the first slit is completed a second one is 
made parallel to and slightly curving toward the first, without 
change of position of the insect. The ovipositor, however, is 
thrust in at a very considerable angle from that assumed in the 
first case, so that it crosses beneath the bark the cut first made, 
and the narrow intervening bark between the two incisions is 
cut entirely loose. This has a very important bearing on the 
subsequent condition of the wounds made by the insect in oviposi- 
tion. The object is doubtless to cause a certain cessation of 
growth between the two rows of eggs, to prevent their being 
crushed and choked out by the rapid growth of the twig, and it 
is due to this peculiarity that the injury to the young limbs later 
assumes so serious a nature. A single incision made by the in- 
sect to contain its eggs would heal over and cause little after 
damage, but with the combination of two incisions and the kill- 
ing of the intervening bark, causing it to adhere to the wood, a 
large scar is produced, which, with each subsequent year’s growth, 
enlarges and ultimately assumes an oval form, the dead bark of 
the center breaking out. 
“After a few years, limbs which have been thickly worked 
on by the insect become very scabby and rough, are easily broken 
off by the wind, and are very liable to attack by wood-boring . 
insects. After completing the two complementary slits and fill- 
ing them with eggs, the female rests a considerable time before 
again beginning operations. The number of eggs deposited by 
a single female exceeds 100, and possibly 200. Rather late in 
the fall a female which had just finished a pair of slits which 
contained some 20 eggs, was found to still contain 40 eggs in 
her ovaries. The adults first appear the middle of July, and 
become most numerous during August and September. They 
begin oviposition about the middle of August, or even earlier, and 
continue this work until they are killed by the frosts of early 
winter. In Kansas I have found them busily ovipositing as late 
as the 24th of October. The eggs remain unchanged or dormant 
in the twig until the following spring, hatching in May or 
early in June. — 
