COPY OF A LETTER 



FROM 



THOMAS MARSHAM, ESQ. TR. L. S. TO THE AUTHOR 



ON THE 



SUBJECT OF INSECTS DESTRUCTIVE TO PINES 



DEAR SIR, 



Baker Street, June 6, 1803. 



Agrekably to your desire, I have perused with care and attention the several letters 



from your friends in Wiltshire respecth.g the insect which attacks the various species of Pine trees in that 



county. It is evidently the Dermestespinipcrda of Liiina^us, (Ips piniperda of Coleoptera Britannica and De 



Geer) and although apparently so common and destructive, is yet hut little known in its larva or grub state, 



for all the observations seem to relate to the perfect insect, whereas most animals of this kind are, in general, 



found to he far more mischievous in their primary or larva state. Linnaeus observes that it perforates the 



inferior branches of the Pine; De Geer remarks, that he has found it in the wood of weak trees, and also 



within the young green branches, which it hollows interiorly by eating the substance, and this causes the 



branches to dry and perish; but neither of those authors mentions the particular species of Pine to which it 



gives a preference. Mr. Wickham in his letter to yon states that he found it on Pinus sylvcstris, Pinea, and 



Strobus, but that its greatest ravage was on Pinus sylvcstris; that he had not perceived it on Plnus Cembra, 



abies, or on either species of Larix. Mr. Davies observes, " that it bores a hole through the shoots of the 



" last spring about eight inches from the summit, and then works its way up the pith, whereby the branch 



*' withers and breaks off; and as it attacks not only the main leader, but also the side leaders, of course the 



" tree will lose all its leaves the second year, and must inevitably die." The devastation mentioned by the 



Duke of Somerset and Lord Malmsbury, which had taken place in the Pino forests in Germany, I am of 



opinion cannot be attributed to the Ips piniperda, but to the larva of the Phal^na Bombyx Monacha of 



Limiasus, which consumes the leaves of the Pine, and which you as well as myself have been lately informed 



has destroyed whole forests thirty miles in extent. D. Johann. Heinrich Jordens, in a work published in 



German in the year 1798, says, that the larva of this moth has discovered its mischievous tendency these 



two years, by entirely destroying the forests of Schlier and Ebendorf, and has now begun to spread itself 



on the confines of Voightland towards Bayreuth, where it attacked in a circumference of eight to ten German 



miles (i. e. forty-eight to sixty English) several larger and smaller forests. In 17^4, he observes, that in the 



Selber forest it eat up the Fir as well as the Pine trees; but this circumstance had not been noticed in general, 



and he thinks that notliing but extreme hunger could force them to attack the needles of the Fir tree. Tiie 



larva of the Tenthredo Pini is another very pernicious little animal; a fcAv of them were sent some years since 



from Scotland, which I had to examine : they had destroyed an immense and valuable plantation of Pines. This 



latter insect is very accurately described by that celebrated Swedish naturalist the Baron De Geer. The 



Curculio Pini and Curculio Abietis are said to be very prejudicial to trees of the Genus Pinus, but as the 



larvce of these, I presume, feed on the substance of the wood, their larvae are but little known. Six other insects 



are also enumerated by the German writers as destructive to the Pine, viz. Dermestes Typographus, Poly- 



graphus, Micographus, and Calcographus, Dermestes Scolytus, and Cerambyx Inquisitor; to which a much 



longer list might be added, l^otli of those that feed on the leaves and those that penetrate into the trunk itself. 



We have most if not the whole, of these insects in our own country, but happily we hear but of little mis- 

 chief occasioned by them, and they are but rarely found. Of Dermestes Typographus I have never yet found 

 a sino-le specimen • and of Phala^na monacha but one, during the number of years that I have made this branch 

 of sconce the amusement of my leisure hours. The Dermestes Scolytus seems with us to confine its ravages 

 to the Elm of which mischief I have been lately an eye witness. I have thus endeavoured to comply with 



2 X 



