CHAP. CXIII. 



CONJ'FERJE. 



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 Rossmassler, it is chiefly young trees of Pinus 

 , i, ,.,.;. nn,\ JMii<ic OV/->O!CQ uuKif-li Q i* o /- ir oi K\7 tV\i<i snpp.ips. Another 



sylvestris and 



excelsa which are attacked by this species. Another 



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

 " s. Suec., iii. 168.), "habitat in frondibus et ligm 



10 Pini et 



to Gyllenhal (Ins 



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 (Fabricu Leach). An interesting memoir has recently been 



published by Dr. Rutzeburg in the last volume of the Nova Acta Nature 



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 j 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 yTbies excelsa as the habitat of Pissodes 



pineti ; A^bies excelsa, as that of Pissodes Hercyniae, 



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. Succ.,\. 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. (Obswv. EntomoL, 1836, p. 27. 



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



very nearly allied to the family Curculionidae, 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 yTbies ex- 2012 



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

 perforat et exsiccat etiani 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 I found it had emerged through the central buds, at 



