HEMIPTERA. 117 
‘It is in the froth that the larve change into pupz, and do not 
leave their habitation to undergo their final metamorphosis. They 
have then, says De Geer, the art of causing the froth inside to 
evaporate and dry up, in such a manner as to form a space inside 
the mass of froth, in which their bodies are entirely free. The 
exterior froth forms a roof closed in on all sides, under which the 
insect lies quite dry. 
In this vaulted cell, the pupa disengages itself little by little 
from its skin, which first splits up along the head, and then on 
the thorax. This opening is sufficiently large to enable it to 
come out of its envelope. It is in the month of September that 
these insects are particularly abundant, when the trees and plants 
are covered with them. Sometimes the froth drips off, like a sort 
of small rain, from branches which are covered with it. Towards 
the autumn the females are gravid. They are then so heavy, that 
they can hardly jump or fly. The males, on the contrary, make 
prodigious bounds; they throw themselves sometimes forward to 
a distance of more than two yards. They are very difficult to 
catch, and still more difficult to find again when one has once let 
them escape. And so Swammerdam calls these insects Sauterelles- 
Puces (Flea-Grasshoppers), because they jump 
like fleas. 
All that we have said relates to the Aphro- 
phora spumaria, or Froghopper (Fig. 85), an 
insect common all over Europe, and which (Epi ens smunariny. 
Geoffroy calls the Cigale bedeaude. 
“Tt is of a brown colour,” says Geoffroy, “ often rather greenish. 
Its head, its thorax, and its elytra, are finely dotted ; on these last 
one sees two white oblong spots. The lower part of the insect is 
light brown.’’* 
We will mention, as it belongs to the group with which we are 
now occupied, a noxious insect, the Jassus devastans, which since 
1844 seems to have taken up its quarters in the commune of 
Saint Paul, in the department of the Basses-Alpes. It sucks the 
leaves and stalks of cereals, causing them to wither, and may be 
found even in winter on young corn, but principally in the spring. 

* “ Histoire abréoée des Insectes, dans laquelle ces animaux sont rangés dans un 
ordre méthodique.” In 4to., an VII. de la République, tome i., p, 416. 
