104 TREE-HOPPERS. 
song is a high and sharp trill frequently heard during the hottest 
days in midsummer. This sound seems to fill the air around us, 
and it is not easy to distinguish from which tree it comes. When 
we at last discover the musician it is found sitting upon the 
trunk and larger branches of the tree, but it requires a very 
cautious approach to observe it, as otherwise the insect flies to 
another tree, almost with the swiftness of a bullet, and with a 
loud humming noise. 
This species is found every season. According to Com- 
stock it requires only two years for its development, and as there 
are two broods or generations of this species, the adults appear 
every year. 
Other and much smaller species occur in our state, and some 
are entirely confined to the prairies. None are of any great 
economic importance in Minnesota. : 
A number of other species are also found in our state, even 
in the prairies, but as all have, as far as known, similar habits, 
it is not necessary to describe them. 
FAMILY MEMBRACIDAE. 
(Tree-hoppers). 
“Nature must have been in a jolly mood when the tree- 
hoppers were developed, for these little creatures are most com- 
ically grotesque in appearance. In general outline they resemble 
beech-nuts, except that many have humps on their backs. The 
prothorax is prolonged backwards over the body like a roof, often 
quite covering it.’ (Comstock). 
Membracide are the most typical Homoptera. They have 
three-jointed tarsi; are of every conceivable form; arched, com- 
pressed, depressed, hump-backed, spindle-shaped, pointed at both 
ends, inflated, hemispherical, or conical, and besides this they are 
furnished with an endless variety of superficial attachments. Their 
feelers are short, like bristles, thick at the base, and placed be- 
neath the expanded margin of the clypeus. All are good leapers, 
with strong legs armed with spines on the tips of the hind tibie. 
Tree-hoppers subsist upon the juices of many kinds of 
plants, but in most cases are not numerous enough to cause any 
real damage. When they rest upon twigs they resemble thorns; 
