CHAP. CXIU. 



CONl'FER^:. ^BIE'TINiE. 



2141 



the author of the mischief was an insect ; for mice would only attack the green 

 and healthy bark : and, indeed, the insects proved to be no other than the Hy- 

 lobius abietis. According to Rossmiissler, it is chiefly young trees of Pinus 

 sylvestris and ;f bies excelsa which are attacked by this species. Another 

 species of the same genus is the Hylobius pinastri Dejean, which, according 

 to Gyllenhal (Ins. Suec^nx. 168.), "habitat in frondibus et hgno Pmi et 

 Abietis." 



The species of another genus of weevils (Pissodes Germar) are also very 

 destructive to different species of the pine and fir tribe. Gyllenhal describes 

 five species ; three only of which have been detected in this country, and all 

 of them are here of great rarity; namely: P. pini Linn., P. notatus Fabr. y 

 and P. pineti (Fabricii Leach). An interesting memoir has recently been 

 published by Dr. Ratzeburg in the last volume of the Nova Acta Natures 

 Curiosorum (vol. xvii. p. 424.), in which the habits of the two first-named 

 species are given in detail. Fig. 2012. shows the mode 

 in which young trees are attacked ; the tree being four 

 years old when the drawing was made. The passage 

 of the larva is here marked with the letter a ; the 

 abode of the pupa, or cocoon, as it may be termed, 

 with the letter b ; and c indicates the opening through 

 which the perfect insect escapes. Gyllenhal gives Pinus 

 sylvestris and yi v bies excelsa as the habitat of Pissodes 

 pineti ; ^4 v bies excelsa, as that of Pissodes Hercynias, 

 notatus, and piniphilus; but he describes the economy 

 of Pissodes pini as being more general : " Habitat in 

 arboribus resinosis, praesertim in abietis frondibus et « 

 ligno nuper caeso,frequens." (Ins. Suec.,\. pars 3. p. 66.) 

 Dr. Heer has also recently described the metamor- 

 phoses of another species of the same genus (Pissodes 

 piceae Illiger}, of which many larvae and pupae were 

 discovered in the trunk of Picea vulgaris in the 

 middle of June, 1835. (Observ. Entomol., 1836, p. 27. 

 tab. iv. b.) There is also another tribe of small beetles, 

 very nearly allied to the family Curculionidse, but in 

 which the head is not produced into a muzzle, of which 

 several of the species are very destructive to the trees 

 of this genus. They constitute the genus Hylurgus 

 of Latreille, and were included by Fabricius in his 

 genus Hylesinus. The species H. piniperda, ligniperda, 

 ater, palliatus, and angustatus, are recorded as in- 

 habitants of fir plantations. Rossmassler gives the 

 first of these as an enemy to old trees of ^Tbies ex- 2012 



celsa ; but Gyllenhal says of it, " Habitat in Pini sylvestris ramulis, quos 

 perforat et exsiccat etiam in ligno et sub cortice, frequens." The following 

 observations and figures relative to the economy of this species were com- 

 municated by Dr. Lindley to Mr. Curtis : — " For the purpose of examining 

 its proceedings more narrowly, I placed a shoot of the Scotch pine under 

 a glass with the insect. In about three hours afterwards, it had just 

 begun to pierce the bark of the base of one of the leaves. Its mandibles 

 seemed chiefly employed, its legs being merely used as a means of fixing 

 itself more firmly. Four hours after, its head and thorax were completely 

 buried in the shoot ; and it had thrown out a quantity of wood, which it had 

 reduced to a powder, and which nearly covered the space under the glass. In 

 sixteen hours more, it was entirely concealed, and was beginning to form its 

 perpendicular excavations, and was busily employed in throwing back the 

 wood as it proceeded in destroying it. There were evidently two kinds of 

 this sawdust ; part consisting of shapeless lumps, but the greater portion of 

 very thin semitransparent lamellae, or rather shavings. I now examined it every 

 day, till the fifth ; when 1 found it had emerged through the central buds, at 



