AND OTHER INSECTS WHICH INFEST CONIFERS. 127 



letters in appearance, whence the insect has sometimes been popu- 

 larly styled the " Typographer Beetle" or Bostrichus typographies 

 (Fabricius). Should silver firs he scarce in the plantation, or 

 the insects he so numerous as to overrun all the trees of that 

 species, they will next attack any other fir or pine that may he most 

 convenient. 



The full period necessary for the development of this mischievous 

 little creatine is about eight weeks from the egg to the full-grown 

 beetle, and there are generally two broods in each season, the last 

 sometimes remaining (owing to cold or wet weather) concealed dor- 

 mant under the bark of the tree till the following spring, when 

 they are fully developed. The injury to the silver fir by this insect 

 will thus be seen to be effected by the destruction of the sap-wood, 

 which every arborist is aware will insure the speedy death of the 

 tree, even when otherwise perfectly sound and luxuriant. A short 

 description of this most destructive insect may here be interesting. 

 It is, when full grown, a beetle of from 2 to 2 J lines long, and 

 about 1 to 1^ lines broad, and hairy. On its first development to 

 the perfect state, and while still under the bark, it is of a rusty 

 yellow colour, becoming darker by degrees, and upon its escape to 

 the open air is of a brownish black ; jaws sharply toothed ; eyes dark 

 brown ; wing-cases deeply punctured, broader behind, deeply and 

 obliquely impressed ; the impressions with crescent-shaped margins, 

 which have from 4 to 6 irregular teeth. Thorax and sternum 

 always darker than the wing-cases. The female is distinguished by 

 a thicker abdomen, and is less covered by the wing-cases. The 

 larva or maggot is 3 lines long, wrinkled and white when it leaves 

 the egg, soon becoming yellowish at the head ; the back reddish 

 striped ; jaws sharp ; antennre short ; feet six in number and 

 yellowish. The nymphs or pupae are white and soft at first, becom- 

 ing harder and yellower by degrees ; they are almost the form of 

 the beetle, only with pale indications of the wings, and with the 

 feet drawn up under the body.* 



The bark-boring order of insects are not only very numerous, but 

 they are probably, from their mode of attack, the most destructive 

 of all to whose ravages the pine family are liable. !Nbt only is 

 their process of destroying the inner bark and alburnum very detri- 

 mental to the tree, but the myriads of little cell-holes which they 

 cut in the bark, even if their further operations be suspended or 

 prevented, interrupt the course of the descending sap, and admit 

 * Kollar on Insects, Loudon's Translation, p. 358. 



