NEW ENGLx\iSi> FAllMEU. 



1 



Dec. •^i, I.^O. 



=* i« 



ticular air or soil, inattention to the evil at the 

 proper time for effectually checking it, &c.) the 

 number of insects which attack trees becomes in- 

 creased beyond its due limit, wo mast either apply 

 the axe without scruple to the seat of the disease, 

 or make up our minds to submit to the utter des- 

 truction of our plantations." 



the natural history of that particular species of i moving the trunks from the vicinity of the sounj I •"'' 



destructive insect which may have occasioned the 

 mischief." 



"Of the evil which is mentioned above in general 

 terms St. James' and Hyde Parks afford us at pres- 

 ent too many examples. The elm trees in both, 

 and particularly in the former are rapidly disap- 



"Almost ell timber-eating insects are comprised j pearing, and unless decisive mcasuret, be soon 

 in three orders, viz. Cokoplera, or beetles ; Lepi- taken to resist the progress of the contagion, we 

 doplera, or moths, butterflies, &c. ; ai'.d Hjjmcnop- must not only expect every tree o. this species to 

 tJa, or bees, wasps, &c. All these in their young- be destroyed in the parks, but may have to regret 

 est state are worms or larvae, and it is while in the dissemination of the evil throughout the vi- 

 this stage of their life that they commit the direct cinity of London.'' The insect which occasions all 

 iniurv to the trees, either by gnawing oiT the bark, I this havoc is the IIyi-esikl-s Scolvtus oit abri- 

 .-,- b'- devoui-imr the wood. The communication! cus, or Scolytus destructor of Latreide, ot which 

 of the di?case°to other trees is perioJical ; for ' the history is briefly as follows. The perfect in- 

 ■vhen the above mentioned worms or larva; arrive j sect, a small beetle, deposits its eggs about the 

 at their perfect or winged state, the mischief com- j end of Mayor commencement of June, in the 

 mitted by them directly, is comparatively trifling, , crevices and holes of the bark on the trunks of the 

 and. in fact, generally results, not so much from Kims. In the process of laying the eggs which is 

 their voracity, as from their attempts to extricate to the female as to most winged insects the imme- 

 them^elves, and to arrive at the e.Ktcrnal air, or J diate forerunner of death, she perforates a tubular 

 frqm their endeavours to commit their ecrgs to a ^ path beneath the bark, from which the lurvse, 

 proper nidus. L'-,it as they are now winged, and ' hatched from these eggs, proceed nearly at right 

 capable of depositing myriads of eggs, th'e germs ! angles, eating their way in parallel smaller tubes, 

 of as many devouring larvse, the disease is thus which, lying close together, cifeciually separate 



dispersed thrnugho.it the neighborhood of tlie tree 

 oriiiinally lufected. If, however, it be, in this their 

 perfect state, that the insects are most formidable, 



the bark from the tree 



The larvEe remain feeding between the bark and 

 wood throijThout the winter season, and assume 



having attained the power of propagating the dis- the pupa or nymph state about the commencement 

 ease, it is also from an accurate knowledge of 1 of spring, before the end of which the bark of an 

 them, while in tliis state that we can alone derive infected tree appears as if its crevices were full of a 

 any hope of being able to counteract their mis- j very fine saw-dust. " The last change of t!ie in- 

 chief." 1 sect takes place; and'being now winged, it tries to 

 " The first thing, indeed, to be done in all such ! arrive at the external air,for the puriiose of propa- 

 oases is, to asceruun the species of perfect insect, I gating its species, and laying its eggs in other 

 which occasions the disease. The experienced ' trees. Each hole, which now appears as if made 

 naturalist is able from this examination of the worm ' with a gimlet, marks the exit of a perfect insect. 

 or larva which he finds devouring the wood, not In tlie first instance the voracity of the larvse, and 

 only to ascertain Uic order and fijmily, ■^ut often in the second the endeavours of the perfect insects 

 the genus and even the species of winged insect to liberate themselves from the wood, particularly 

 which has produced it; and having determined the when such attempts are made by almost infinite 

 genus or species,it becomes an easy matter to know numbers, soon occasion the bark to fall in large 

 the season of its appearance. None of these tim- pieces. The consequence is that tlie new leaves 

 ber-eating insects remain in their perfect or wing- only make their appearance to wither, and the tree 



wood, is, in reality, to do no good at all." ■ tt""' 



It may_:also be recommended, that no more elij| *"' 

 trees be, during the continuation of the diseasS *" 

 planted in places where it is prevalent." ■ W'J' 



" The Hylesinus destructor is peculiar to t|j i ''"• 

 elm, and was, in all probability introduced into tli *'"• 

 parks with some of the young elms which ha* ''* 

 lately been planted indifferent parts of them.-s .i* 

 The other species of trees, in these places of put *'' 

 lie resort, seem, on tlic v.-hole, to be very free froi i W'" 

 disease, but in planting, and particularly in nrm i *'* 

 mental planting, it may be well to bcjH- in mini 1 "'' 

 that indigenous trees are much more subj'jct I i F' 

 the attacks of our indigenous insects, than tlios ( ''' 

 which arc not natives of this country. With ri < H 

 spect to those trees which are in an unsound sta^ i '"'' 

 it is very difl[icult to point out a cure for them.- • *! 

 Wlien the insects attack the braiiciies, these ougl I li* 

 obviously to be examined, and if infected, ougli i «~ 

 as soon as possible, to be lopped off and burnt. '" 

 scarcely know, however, what to propose, for til 

 preservation of those trees, of which the trunk 

 are infected. Perhaps it may be of use to cove 

 over, in the month of March, with a mixture of li 

 and train oil, to a certain height from the ground 

 all such trees as it may be thought proper to an 

 tempt to save. I venture to recommend thi.i coaC 

 ing of tar, not only by way of experiment, as pro- 

 tecting the trunks from the access of the perfect 

 insects, but for the purpose of filling those little 

 round holes, which it, is easy in summer ("r ;i 

 accurate observer to perceive,- afford pecuii .i 

 cilities for the communication of the disease. ' 



" To those pfrsons who, being unacquainti ■,' iriti. 

 J\/'.iiiir(il liistorij, ni'iy therefore he disposed t<i : i 'j; 

 lect the power of these insects, because they i//, i:<- 

 dividnally minute, and who totally overlook tin n,i 

 siifuxnces of their tieing alaiosl infinite in iiuhiuer, 

 /have only to remark, that they may judge frow. 

 what fJiese animals have already done in the parks 

 how much mischief they are capable of effecting. In 

 the year 1780, an insect, ^Bostukhi s iypugra- 

 phus, ¥.) of the same natural family as the Hr- 

 LESINUS destructor, made its appearance in the 



ed state throughout the year, and rarely for more perishes. The early Entomologi.--ts,little acquaint- pine-forests of the Hartz, and was neglected. In 



than eight weeks. We may therefore easily as- ed with metamorphoses, on finding the perfec 

 certain the proper time for 'cutting down those HvLEsirsvs destructor, (le Scolyte of Geoffroy) on 

 trees which are so much infected with larva;, as to dead or dying trees erroneously considered their 

 afford no hope of saving them ; for it would obvi- decease to be the cause, instead of the effect of 

 ously be the height of imprudence not to seize the the insect's appearance." — "In order to prove that 

 only opportunity of preventing the annual disper- experienced naturalists are now aware of the true 

 sion of the disease, by destroying the brood oflaivw cause of such vegetable diseases, it may be suffi- 

 while yet in the tree.''' cient to cite, from the 3d volume of M. Cuvier's 



" As soon as metamorphosis has t'lken place, as Regne j1nimal,lhe prefatory remarks of M. Latreille 

 soon as the winged insect has made its appearance, on the whole family of insects to which Hylesi- 

 the misciiief for the ensuing year is done. Not :^vs destructor hc\ougs : Most of the Xvlophagi 

 only is time thus lost, and more trees inevitably , live in wood ; in which the larva; pierce or exca- 



destroyed, but the future eradication of the dis 

 ease is rendered much more difficult." 



" We may also derive another advantage from 

 ascertaining the habits of thrt particular insect, 

 which causes the disease, and the season of its ap- 

 pearance, for it is often thus possible, by timely 

 measures, even in places where the perfect insect 

 is prevalent, to prevent any deposition of eggs in 

 such wood as may have remained sound. At all 

 events, the devastation committed by these animals 

 is at times so great, that it is clearly worth while 

 to make experiments to obviate it ; although it is 



vate fuirows in various directions ; and when ve 

 ry numerous in a forest, particularly of pines and 

 firs, they cause to perish, in a few years, vast 

 numbers of trees, or leave them in a state unfit to 

 be usefully employed in the arts." 



Mr Maclcay thinks it advisable to inspect dis- 

 eased Elm trees " in summer, when the perfect 

 insect is on the wing, and again in winter, when 

 the trees much infected should be cut down and 

 burned with the larvEe in them, or be immediately 

 subjected to such heat or fumigations as may ef- 

 fectually destroy the larva;, which at this season 



difficult to conceive how such experiments can ev- 1 are near the surface, and therefore not so difficult 

 e.t be made philosophically by persons who do not in ; to kill. To rest content with having cut down the 

 the first instance make themselves acquainted with | trees, without destroying the larvte, or even re- 



1783, whole forests had disappeared, and, for want 

 of fuel, an end was nearly put to the mining op- 

 erations of this extensive range of country. At 

 the present moment, also, the French Govern 

 ment is in alarm at the devastation committed in \n 

 their arsenals, by an insect well known to natu- 

 ralists, under the name of Lymexylon navale.~- 

 About ten years ago, the principal naval engineer 

 at Toulon, M. de Cerisier, who happened to be 

 conversant with Entomology, discovered this in- 

 sect in the dock-yards, and recommended certai 

 precautions to be taken for the preservation of thi 

 timber there lodged. The French Governme: 

 objected to the expense requisite for obviating ah 

 evil, of which, as yet, they had no experience ; 

 and now, when perhaps it is too late, the minister 

 of marine has determined to follow M. de Cerisier's 

 advice." 



This circumstance brings to recollection the im- 

 portant service rendered by Linnaeus to his native 

 country and the high compliment paid by his king 

 in following the directions of this distinguished 

 naturalist, and strikingly exemplifies the utility ofl 

 entomological knowledge in economics. Sir Jamesi 

 E. Smith says that Linna;us, at the desire of thti 

 king of Swedi;n, traced out the cause of the des- 

 truction of the oak timber in the royal dock-yaTd»;i 





