L 
: 
meee eal ery : . 
7 
r INSECTS INJURIOUS TO THE OAK. oT 
~ marked by Harris and others, it appears at different years in places not far from each 
other. So that while in Plymouth and Sandwich we may look for its reappearance 
in 1889, in Fall River it will come in 1885, or four years earlier. 
There are three species of Cicada in the Northern States, and, in order that they 
may not be confounded in studying the times of appearance of the different broods of 
the seventeen-year species, I add a short description of each form, so that they may 
be readily recognized in the winged and immature states. 
Fic, 9.—The seventeen-year Cicada and pupa; (a,b), d, position of eggs (e); f, larva.—After Riley. 
The two larger species are the seventeen-year locust (Cicada septemdecim) and the 
dog-day cicada (C. pruinosa). Fig. 9, copied from Riley’s report, gives a good idea 
of the former species: a represents the pupa, 6 the same after the adult has escaped 
through the rent in the back, ¢ the winged fly, d the holes in which the eggs e are in- 
serted. Fig. 9, f represents the larva as soon as hatched. The adult may be known 
by its rather narrow head, the black body, and bright red veins of the wings. The 
wings expand from two and a half to three and a quarter inches. 
The pupa is long and narrow, and compared with that of C. pruinosa the head is 
longer and narrower, the antenne considerably longer, the separate joints being 
longer than those of the dog-day locust. The anterior thighs (femora) are very large 
and swollen, smaller than in C. pruinosa, though not quite so thick, with the basal 
Spine shorter than in that species, while the snag or supplementary tooth is larger and 
nearer the end; the next spine, the basal one of the series of five, is three times as 
large as the next one, while in C. pruinosa it is of the same size, or, if anything, 
smaller. The toe joint (tarsus) projects over two-thirds of the length beyond the end 
of the shank (tibia), while in the other species it only projects half its length. The 
terminal segment of the body is rather larger than in C. pruinosa. The body is shin 
ing gum-color or honey-yellow, with the hinder edge of the abdominal segments 
thickened, but no darker than the rest of the body. Length, one inch (.90-1.00); 
width, about a third of an inch (.35), being rather smaller than that of C. pruinosa and 
much larger than that of C. rimosa. 
25. THE WHITE-LINED TREE HOPPER. 
Thelia univittata Harris. 
Order HEMIPTERA; family MEMBRACID®, 
Common upon oak limbs and twigs, puncturing them and sucking their juices. 
This tree hopper is found on the oak in July. It is about four-tenths 
