INSECTS. 305 



they pass through their change to the perfect insect. 

 They exercise a wonderiul instinct in leaving just fibres 

 enough to support the branch until they are ready for 

 their descent, but it often happens that the twig breaks 

 off partially and hangs by a tiiread, dying, of course ; we 

 see the brown leaves on the trees, and this is the first indi- 

 cation of the presence of the insects. If we examine the 

 fallen spray, we shall be surprised to observe the cause of 

 its falling. In the case of the oak tree, the damage is done 

 by the Elaphidion viUosum, (Fabricius), a long-horned 

 beetle. The larva remains in these twigs until the next 

 season, hence the importance of gathering and burning 

 all that fall to die ground. 



An insect of somewhat similar habits often cuts off 

 s-tout shoots of the Hickoiy, making a very neat section 

 of a small limb, leaving only the bark, so that it readily 

 breaks off with tlie wind ; and a similar effect has been 

 observed in strong annual shoots of the pear, toward the 

 end of summer. The fallen piece and the stump ar^ cut 

 as neatly as by the shears, but no perforation is discovered 

 along the axis, in which the larva could be concealed ; 

 hence we have but to suffer the trimming thus peiformed 

 without our will, and look upon it as a sort of natural 

 shortening-in of our trees. 



Blister-flies, or BeetleSi — There are several species of 

 these insects, each of which appears to have its favorite 

 pasturage. They are exceedingly voracious, but confine 

 themselves chiefly to the destruction of herbaceous vege- 

 tation, and are therefore obnoxious to the farmer and gar- 

 dener, who know them as the potato insects, than to the 

 fruit-grower. Their appetites are not very discriminating. 



