114 THE INSECT WORLD. 



a new and sufficient quantity of froth, which it takes care to add to 

 its first stock."* 



It is in the froth that the larvae change into pupae, and they 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, and then 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 pregnant. They are then so heavy that that they can hardly jump 

 or fly. The males, on the contrary, make prodigious bounds ; they 

 throw themselves 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 Satiterelles-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 

 Fig. 8 S .-The Froghopper Geoffroy calls the Cigale bedeaude. 

 (Aphrophara spumaria). " It is of a brown colour," says Geofiroy, 



" 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." f 



We will mention, as it belongs to the group with which we are 

 now occupied, a noxious insect, lassus devastate, 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. According to M. 

 Gue'rin-Mdneville, its head is of an ochrey yellow, with the apex 



" Memoires pour servir a 1'Histoire des Insectes," tome iii. 

 t " Histoire abrege"e des Insectes, dans laquelle ces animaux sont ranges dans 

 un ordre methodique. In 410. Tome i., p. 416. An VII. de la Republique. 



