172 INDIRECT INJURIES CAUSED BY INSECTS. 



the great naturalist just mentioned, at the desire of the king of Sweden, 

 traced out the cause of the destruction of the oak-timber in the royal 

 dock-yards; and, having detected the lurking culprit under the form of a 

 beetle (Lymexylon navalc), by directing the timber to be immersed during 

 the time of the metamorphosis of that insect and its seasons of oviposition, 

 furnished a remedy which effectually secured it from its future attacks.^ 

 No Coleopterous insects are more singular than those that belong to the 

 genus panssus L. ; and one of them, at least, remarkable, it is said, for 

 emitting a phosphoric light from the globes of its antennce, is also a tim- 

 ber-feeder- ; and the genus Trypoiylon, many species of Crahro, Eumeiics 

 parietum, Latreille's genera Xylocopa, Chelostoma, Heriades, Megachile, 

 and Anthophora (all separated from Apis L.), perforate posts and rails 

 and other timber, to form cells for their young. ^ 



The Linnean order Aptera furnishes another timber-eating insect, a 

 kind of wood-louse (^Limnoria terebrans of Dr. Leach), which though 

 scarcely an eighth of the size of the common one in point of rapidity of 

 execution seems to surpass all its European brethren, and in many cases 

 may be productive of more serious injury than any of them, since it 

 attacks the wood-work of piers and jetties constructed in salt water, and 

 so effectually as to threaten the rapid destruction of those in which it ha^ 

 established itself. In December, 1815, I was favored by Charles Lut- 

 widge, Esq. of Hull, with specimens of wood from the piers at Bridlington 

 Quay, which wofully confirm the fears entertained of their total ruin by 

 the hosts of these pigmy assailants that have made good a lodgement in 

 them, and which, though not so big as a grain of rice, ply their mastica- 

 tory organs with such assiduity as have reduced great part of the wood- 

 work which constitutes their food into a state resembling honeycomb. 

 One specimen was a portion of a three-inch fir plank nailed to the 

 North Pier about three years before, which is crumbled away to less than 

 an inch in thickness — in fact, deducting the space occupied by the cells 

 which cover both surfaces as closely as possible, barely half an inch of 

 solid wood is left ; and though its progress is slower in oak, that wood is 

 equally liable to be attacked by it.'' If this insect were easily introduced 

 to new stations, it might soon prove as destructive to our jetties as the 

 Teredo navalis to those of Holland, and induce the necessity of substituting 

 stone for wood universally, whatever the expense : but happily it seems 

 endowed with very limited powers of migration ; for, though it has spread 

 along both the South and East Piers of Bridlington harbor, it has not yet, 

 as JNIr. Lutwidge informs me, reached the dolphin nor an insulated jetty 

 within the harbor. No other remedy against its attacks is known than 

 that of keeping the wood free from salt water for three or four days, in 

 which case it dies ; but this method, it is obvious, can be rarely appli- 

 cable.^ 



' Smith's Introduction to Botany, Pref. xv. * Afzelius in Linn. Trans, iv. 261. 



3 Kirby. 31on. Ap. Ang. i. 152. 191. Latreille, Gen. iv. 1(>1 — . 



* See llie elnborate memoir of Mr. Coldstream in Edin. Xerv Phil. Journ. April, 1834 ; 

 remarks on this insect by the Rev. F. W. Hope in Trans. Ent. Soc. Land. i. 119. ; also by 

 Dr. Moore, in Mar;, of Nat. Hist. N. S. ii. 206., who stales that its injurious effects have 

 been known at least forty years in the harbor at Plymouth, where it is called the "gribble." 



' In order to ascertain how [ar pure sea water is essential to this insect, and consequently 

 what danp;er exists of its being introduced into the wood-work of our docks and piers com- 

 municating with our salt-water rivers, as at Hull, Liverpool, Bristol, Ipswich, Ace, where 



