298 DIVISION III. ARTICULATED ANIMALS.—CLASS IV. INSECTA. 
young attain their growth in the grub state, they fall to the ground, and 
make their way two or three feet under the surface, to undergo their change 
into the pupa form. As soon as they undergo their last metamorphosis, 
they make their appearance, and commence their destructive career. 
Many of the grasshopper tribe, especially of the musical kinds, are erro- 
neously designated, by the common people, by the name of Locust. These 
musical insects are usually of a green color and nocturnal habits. They 
conceal themselves, during the day, in the grass, or foliage of trees; but at 
night they quit their hiding-places, and the exhilarated male makes the air 
resound with the song of love, by which he seeks to charm his silent partner. 
One of the best known of the insects is the “ Karypip” (Locusta concava, 
Say). Its large, oblong-oval, concave wing-cases enwrap the abdomen, 
and meet at their edges, above and below, very like the two sides of a pea- 
pod. Perched on the topmost twig of a tree, the insect begins its nocturnal 
call by separating, closing, and reopening his wing-cases. The friction of 
the tabouret frames upon each other thrice produces three distinct notes, 
which is the usual number, although sometimes only two are given. The 
mechanism of these organs reverberates and increases the sound to such a 
degree, that it may be heard, in the stillness of the night, a quarter of a 
mile. At intervals of three or four minutes, the joyous insect repeats his 
sonorous chant, while rival songsters echo the notes, and the woods resound 
with the ery of “ Wuty did! Haty did't!” through the entire night. 
The most destructive variety is the Migratory Locust, which is very 
common in Africa, India, and throughout the whole of the East. This 
insect is greenish, with transparent elytra of dirty gray, whitish wings, and 
pink legs. A second variety (the Italian Locust) also does a great deal of 
damage in the South. All these locusts undergo five moults, which take 
six weeks each; the last takes place at the end of the hot weather, towards 
the autumn. 
It is especially in warm climates that they become such fearful pests to 
agriculture. Wherever they alight, they change the most fertile country 
into an arid desert. They are seen coming in innumerable bands, which 
from afar have the appearance of stormy clouds, even hiding the sun. 
As far and as wide as the eye can reach, the sky is black, and the soil is 
inundated with them. The noise of these millions of wings may be com- 
pared to the sound of a cataract. When this fearful army alights upon the 
trees, the branches break, and in the course of a few hours, and over an 
extent of many leagues, all vegetation has disappeared ; the wheat is gnawed 
to its very roots ; the trees are stripped of their leaves ; everything has been 
destroyed, gnawed down, and devoured. When nothing more is left, the 
terrible host rises, as if in obedience to some given signal, and takes its de- 
