CHAP. CXIII.

CONI'FERjE. ^BIE'TINiE.

2141

the author of the mischief was an insect; for mice would only attack the greenand 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 Pmussylvestris and A'bies excelsa which are attacked by this species. Anotherspecies of the same genus is the Hylobius pinastri Dejcan, which, accordingto Gyllenhal {Ins. Suec., iii. 168.), “habitat in frondibus et ligno Pini etAbietis.”

The species of another genus of weevils (Pissodes Germar ) are also verydestructive to different species of the pine and fir tribe. Gyllenhal describesfive species; three only of which have been detected in this country, and allof them are here of great rarity; namely: P. pini Linn., P. notatus Fabr.,and P. pineti (Fabricit Leach). An interesting memoir has recently beenpublished by Dr. Ratzeburg in the last volume of the Nova Acta NatunsCuriosorum (vol. xvii. p. 424.), in which the habits of the two first-namedspecies are given in detail. Fig. 2012. shows the modein which young trees are attacked; the tree being fouryears old when the drawing was made. The passageof the larva is here marked with the letter a; theabode of the pupa, or cocoon, as it may be termed,

■with the letter b; and c indicates the opening throughwhich the perfect insect escapes. Gyllenhal gives Pinussylvestris and A'bies excelsa as the habitat of Pissodespineti; ^f'bies excelsa, as that of Pissodes Hercynise,notatus, and piniphilus; but he describes the economyof Pissodes pini as being more general: “ Habitat inarboribus 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 (Pissbdespic e&Illiger), of which many larvae and pupae werediscovered in the trunk of Pfcea vulgaris in themiddle 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 Curculionidae , but inwhich the head is not produced into a muzzle, of whichseveral of the species are very destructive to the treesof this genus. They constitute the genus Hylurgusof Latreille, and were included by Fabricius in hisgenus Hylesinus. The species H. piniperda, lignipdrda,

|>ter, palliatus, and angustatus, are recorded as in-habitants of fir plantations. Rossmassler gives thefirst of these as an enemy to old trees of A'bies ex-celsa; but Gyllenhal says of it, “Habitat in Pini sylvestris ramulis, quosperforat et exsiccat etiam in ligno et sub cortice, frequens.” The followingobservations and figures relative to the economy of this species were com-municated by Dr. Lindley to Mr. Curtis: —“For the purpose of examining'ts proceedings more narrowly, I placed a shoot of the Scotch pine under? glass with the insect. In about three hours afterwards, it had just™gun to pierce the bark of the base of one of the leaves. Its mandiblesseemed chiefly employed, its legs being merely used as a means of fixingj . “ore firmly. Four hours after, its head and thorax were completelyuried in the shoot; and it had thrown out a quantity of wood, which it hadreduced to a powder, and which nearly covered the space under the glass. Insateen hours more, it was entirely concealed, and was beginning to form itsPerpendicular excavations, and was busily employed in throwing back therood as it proceeded in destroying it. There were evidently two kinds ofis sawdust; part consisting of shapeless lumps, but the greater portion ofwy thin semitransparent lamellae, or rather shavings. I now examined it everya y> till the fifth; when I found it had emerged through the central buds, at

2012