THE GRAPE LEAFHOPPER IX THE LAKE ERIE VALLEY, 
33 
one instance of parasitism was noted. In this instance, on July 31, 
1907, Mr. P. K. Jones, of the Bureau of Entomology, observed the 
female of Aplielopus sp. in the act of thrusting her ovipositor into 
the body of a nymph. No attempt was made to determine if eggs 
were deposited in the body of this nymph, nor was any further evi- 
dence of parasitism of the nymphs or the adults of the grape leafhopper 
observed. 1 
On the other hand, the nymphs seem to be especially subject to the 
attack of many predaceous insects, mites, and spiders, while the 
adults become entangled in spider webs and are 
preyed upon by the occupants. 
The literature on the grape leafhopper con- 
tains the following records of attack by preda- 
ceous enemies on either the nymphs or the 
adults: 
B. D. Walsh, in IS 62, records Hemerodromia 
superstitiosa Say, one of the dance flies, as "feeding 
on the "hoppers" in Illinois. 
Townend Glover, in 1875, records Hi/aliodes 
vitripennis Say, the glassy-winged soldier-bug, 
as feeding on the nymphs. 
M. Y. Slingerland, in 1902, records a mite, 
RJiyncholopJius parvulus Banks, the larva? of 
Chrysopa, and aphis lions as feeding on the 
nymphs. 
J. H. Quayle, in 1908, records the destruction 
of the nymphs by the beetles and larva? of lady- 
birds, aphis lions, and ants, but states that all 
of these predaceous enemies put together have little apparent influ- 
ence in lessening the number of the pest. 
During the investigation of this pest at North East, Pa., aphis 
lions, ants, mites, and spiders were frequently observed preying upon 
the nymphs, and in addition to them a very active orange-colored 
mite (Anystis agilis Banks) was often found feeding upon the nymphs 
and occasionally upon the adults, especially just after the latter had 
transformed and had not the full use of their wings. Both the nymph 
and the adult of a capsid of the genus Diaphnidia near D. Ixamata 
Yan Duzee were frequently found with nymphs of T. comes impaled 
on their long probosces. Yet all of these predaceous enemies com- 
bined failed to have any appreciable influence in reducing the destruc- 
tive numbers of the leafhopper. 
Fig. 13.— Adult grape leaf- 
hopper parasitized by a 
dryinid, and showing 
cocoon of parasite pro- 
truding from abdomen, at 
left. Greatly enlarged. 
(Original.) 
1 While Mr. J. F. Strauss, of this bureau, was making drawings of adults of T. comes for this paper he 
found an adult among some material in alcohol with the pupa of a dryinid (see fig. 13) attached to the body. 
These specimens were collected by the writer in vineyards near Euclid, Ohio, Aug. 9, 1911. 
