216 
HEMIPTERA. 
noitre, but descending again on tlie occurrence of cold or wet 
weather. 
During their temporary residence in these burrows near 
the surface, the Cicada grubs, or more properly pupae, for 
such they are to be considered at this period, though they 
still retain something of a grub-like form, acquire strength for 
further efforts by exposure to the light and air, and seem then 
only to wait for a favorable moment to issue from their sub¬ 
terranean retreats. When at length this arrives, they issue 
fi'om the gi’ound in great numbers in the night, crawl up the 
trunks of trees, or upon any other object in their vicinity to 
which they can fasten themselves securely by their claws. 
After haA’ing rested aAvhile, they prepare to cast off their 
skins, Avliich, in the mean time, have become dry and of an 
amber color. By repeated exertions, a longitudinal rent is 
made in the skin of the back, and throush this the included 
Cicada pushes its head and body, and AvithdraAvs its AAings 
and limbs from their separate cases, and, craAvling to a little 
distance, it leaA'es its empty pupa-skin, apparently entire, still 
fastened to the tree. At first the Avino:-coA"ers and Avino-s are 
very small and opaque, but, being perfectly soft and flexible, 
they soon stretch out to their full dimensions, and in the 
course of a feAv hours the superfluous moisture of the body 
evaporates, and the insect becomes strong enough to fly. 
During seA^eral successive nights the pupae continue to 
issue from the earth; aboA^e fifteen hundred haA’e been found 
to arise beneath a single apple-tree, and in some places the 
AAdiole surface of the soil, by their successiA’e operations, has 
appeared as full of holes as a honeycomb. In Alabama the 
species under consideration leaA^es the ground in Febniary 
and iMarch, in Maryland and PennsylA^ania in May, but in 
^Massachusetts it does not come forth till near the middle of 
June. Within about a fortniMit after their final transforma- 
tion they begin to lay their eggs, and in the space of six 
Aveeks the Avhole generation becomes extinct. 
Fortunately these insects are appointed to return only at 
