182 INSECTA. 
trum is very distinct. The tarsi are terminated by two hooks, and 
the antennze have but six or seven joints. Such is the genus 
Apuis, Lin. 
Which we divide in the following manner : 
APHIS, 
Properly so called, where the antenne are longer than the thorax 
and consist of seven joints, the third of which is elongated ; the eyes 
are entire, and there are two horns or mamille at the posterior extre- 
mity of the abdomen. 
Almost all of them live in society on trees and plants, of which 
they suck the juices with their trunk. The two horns observed at 
the posterior extremity of the abdomen in a great number of species 
are hollow tubes from which little globules of a transparent, honey- 
like fluid frequently exude, on which the Ant eagerly feeds. 
In each community, during the spring and summer, we find 
Aphides that are always apterous, and semi-nymphs whose wings are 
yet to be developed; all these individuals are females, which produce 
living young ones that issue backwards from the venter of their 
mother, without previous copulation. The males, some of which are 
winged, and others apterous, only appear towards the end of summer 
or inautumn. They fecundify the last generation produced by the 
preceding individuals, which consists of unimpregnated apterous fe- 
males. After coition the latter lay their eggs on branches of trees, 
where they remain during the winter, and from which, in the spring, 
proceed little Aphides, which soon multiply without the assistance of 
the males. 
The influence of a first fecundation is also extended to seven suc- 
cessive generations. Bonnet,to whom we are indebted for most of 
these facts, by isolating the females, obtained nine generatiuns in the 
space of three months. 
The wounds inflicted on the leaves or tender twigs of plants, by 
Aphides, cause those parts of the vegetable to assume a variety of 
forms, as may be observed on the shoots of the Lime tree, the leaves 
of Gooseberry bushes, Apple trees, and particularly those of the Elm, 
Poplar, Pistachio, in which they produce vesicles or excrescences en- 
closing colonies of Aphides, and frequently an abundant saccharine 
fluid. Most of these Insects are covered with a farinaceous sub- 
stance, or cotton-like filaments, sometimes arranged in bundles. The 
larvie of the Hermerobii, those of several Diptera, and of Coccinelle, 
destroy immense numbers of Aphides. M. A. Duvau has commu- 
nicated to the Académie des Sciences, the interesting result of his re- 
searches on these Insects. His Memoir has been inserted in the An- 
nales du Muséum d’ Histoire Naturelle. 
A. quercus, L.; Reaum., Insect., IIT, xxviii, 5,10. Brown; 
remarkable for its rostrum, which is at least thrice as long as 
the body. 
