LIBRARY

HEMIPTERA 313
throughout much of the summer.! In years of abundance the noise produced
by the thousands of males is almost deafening, and the females may do considerable
damage to wild and cultivated shrubs and trees by inserting their eggs
and thus killing the small branches.
But this is not the only sound of the cicada. Certain species produce intermittent
buzzings, whirrings, and chirpings, and a considerable number of both
FIG. 106. An early illustration of the periodical cicada, Magicicada septendecim (Linn.).
I, 1st instal'; 2, A. mature nymph; B, cast nymphal skin or exuvia; C, adult with wings spread:
D, egg-punctures in twig; E, eggs removed from punctures; 3, adult with wings folded. (After
Riley, 1869.)
sexes click by beating the fore wings together beneath the body or against the
branches upon which they rest. In some species singing begins at GO°F, and
as long as the temperature is sufficient and the air stin, their songs may continue
until sunset or even into the night. When captured, while singing or even
when still, certain species emit high-pitched notes not unlike a shriek or a call
for help. Cacama crepitans (Uhler) of California is such a species, and even when
removed from the net and held they will cry out when slightly pressed. I have
induced others to sing by carrying them around and occasionally pressing them.
When disturbed, adults frequently flutter to the ground and, if unable to get
1 In China and Japan male cicadas are captured py means of a small amount of bird lime
at the end of a long pole or by means of a net and are kept in very small, artistic cages indoors
where they delight the human occupants with their fervent mating calls.