HEMIPTERA. 205 



upon plants infested with the Thrips. Mrs. N. G. S. Gage, 

 formerly of Concord, N. IL, to whom I am indebted for much 

 valuable information respecting the wheat-fly, or Cecidomyia 

 Tritici, has discovered another pernicious insect in the ears of 

 ffrowinsr wheat. It seems to agree with the accounts of the 

 Thrips cerealium, which, sometimes infests wheat, in Europe, 

 to a great extent. This insect, in its larva state, is smaller 

 than the wheat maggot, is orange-colored, and is provided 

 with six legs, two antennae, and a short beak, and is very 

 nimble in its motions. It is supposed to suck out the juices 

 of the seed, thus causing the latter to shrink, and become what 

 the English farmers call pungled. This little pest may proba- 

 bly be destroyed by giving the grain a thorough coating of 

 slacked lime. 



Aphides, or plant-lice, as they are usually called, are among 

 the most extraordinary of insects. They are found upon 

 almost all parts of plants, the roots, stems, young shoots, buds, 

 and leaves, and there is scarcely a plant which does not harbor 

 one or two kinds peculiar to itself. They are, moreover, ex- 

 ceedingly prolific, for Reaumur has proved that one individual, 

 in five generations, may become the progenitor of nearly six 

 thousand millions of descendants. It often happens that the 

 succulent extremities and stems of plants will, in an incredibly 

 short space of time, become completely coated with a living 

 mass of these little lice. These are usually wingless, consisting 

 of the young and of the females only ; for winged individuals 

 appear only at particular seasons, usually in the autumn, but 

 sometimes in the spring, and these are small males and larger 

 females. After pairing, the latter lay their eggs upon or near 

 the leaf-buds of the plant upon which they live, and, together 

 with the males, soon afterwards perish. 



The genus to which plant-lice belong is called Aphis, from a 

 Greek word which signifies to exhaust. The following are the 

 principal characters by which they may be distinguished from 

 other insects. Their bodies arc short, oval, and soft, and are 

 furnished at the hinder extremity with two little tubes, knobs, 

 or pores, from which exude almost constantly minute drops of 

 a fluid as sweet as honey ; their heads are small, then- beaks 



