388 liNSECTS INJURIOUS TO VEGETATION. 



grubs of the large species come to their growth in seven weeks 

 after the eggs are laid. If this be true, and it seems hardly pos- 

 sible, the chrysalis state must last a long time, for the perfected 

 insects have been known to come out of timber that had been 

 cut up and applied to mechanical uses by the carpenter. Some 

 persons have supposed that they attacked only diseased and de- 

 cayed trees, in which it must be admitted they are often found in 

 great numbers. But many instances might be mentioned of their 

 appetite for sound wood also, and it is probable that the presence 

 of these insects, like that of many others, is the cause and not 

 the consequence of the decay of the trees wherein they live. It 

 is stated in the London " Zoological Journal," that two hundred 

 Scotch firs have been destroyed by the Urocerus Juvenciis, in the 

 woods of Henham Hall, the seat of the Earl of Stanhope, their 

 trunks being bored through and through by the grubs of this in- 

 sect. Mr. Westvvood relates * that a piece of wood, twenty feet 

 in length, from a fir-tree in Bewdley Forest, Worcestershire, 

 England, was found to be so intersected hy the burrows of these 

 grubs, as to be fit for nothing but fire-wood ; and that the winged 

 insects continued to come out of it, at the rate of five, six, or 

 more each day, for the space of several weeks. Mr. Marsham 

 states, on the authority' of Sir Joseph Banks, that several speci- 

 mens of Urocerus gigas were seen to come out of the floor of a 

 nursery in a gentleman's house, to the no small alarm and discom- 

 fiture of both nurse and, children. The grubs must therefore 

 have existed in the boards or timbers before they were employed 

 in building, and these materials would not have been used if in a 

 decayed state. The sexes of most of these insects differ con- 

 siderably in size and color, and in the shape of their body and of 

 <he'n hind-legs. There are not many different kinds, but they 

 are very prolific, and abound in mountainous districts, and in 

 temperate cluTiates, where forests of pines and firs prevail. A 

 new order was proposed for their reception by Mr. Macleay, and 

 was named Bombopera, on account of the humming sound that 

 they make in flying. Their young partake of the nature of tlie 

 wood-eating grubs of the Capricorn beetles, which therefore they 



*" Introduction to the Modern Classification of Insects," Vol. II., p. 118. 



