INDIRECT INJURIES CAUSED BY INSECTS. 12 
Marsham that the grub of B. splendida was ascertained to have existed 
in the wood of a deal table more than twenty years.’ 
Another tribe of internal wood-borers belongs to the genus Sirew of the 
order Hymenoptera. Mr. Stephens informs me that the fir-trees in a 
plantation of Mr. Foljambe’s, in Yorkshire, were destroyed by the larva 
of Sirew gigas ; while those of another, belonging to the same gentleman, 
in Wiltshire, met with a similar fate from the attacks of Sirew juvencus. 
In proof of the ravages made by this last insect, Mr. Raddon exhibited to 
the Entomological Society a portion of the wood of a fir-tree from 
Bewdley Forest, Worcestershire, of which twenty feet of its length was so 
erforated by its larvae as to be only fit for fire-wood ; and being placed 
in an, out-house, five or six of the perfect insects came out every morning 
for several wecks.2. When fir-trees thus attacked are cut down, it often 
happens that the larvee of the species of Sirew inhabiting them have not 
attained their full growth at the time the wood has been employed as the 
joists or planks for floors, out of which the perfect insects, even years after, 
emerge, to the no small surprise, and even alarm, of the inmates. An in- 
stance of this, where several specimens of S. gigas were seen to come out 
of the floor of a nursery in a gentleman’s house, to the great discomfiture 
both of nurse and children, is related by Mr. Marsham, on the authority 
of Sir Joseph Banks*; and a similar circumstance, stated by Mr. Ingpen, 
occurred in the house of a gentleman at Henlow, Bedfordshire, from the 
joists of the floors of which whole swarms, literally “thousands,” of Sirex 
duplex Shuckard*, emerged from innumerable holes, large enough to admit 
a small pencil-case, causing great terror to the occupants. As the house 
had been built about three years (the joists of British timber), there’ 
could be no doubt of the lary having been more than that time in arriy- 
ing at their perfect state.® Amongst the most formidable wood-borers 
with us is the larva of the great goat-moth (Cossus ligniperda®), which 
attacks willows, poplars, and occasionally even elms and oaks; and from 
its large size, and living above two years in the larva state, the holes which 
it makes are a great deduction from the value of the tree, even if it be not 
entirely destroyed. The larvae of Zeuzera esculi, though much smaller, 
has similar habits, and is injurious by boring into apple, pear, and walnut 
trees. 
The insects which attack the bark of trees mostly belong to the family 
of Scolytide Westwood (including the genera Scolylus, Hylesinus, Hylurgus, 
Tomicus, &c.) ; a numerous tribe of beetles, the larva of which, after being 
hatched from the eggs deposited by the parent beetle, excavate in the sub- 
stance of the inner bark, and partly also in the adjoining alburnum or 
sap-wood, lateral parallel channels more or less sinuous, proceeding on each 
side from a central one (that in which the eggs were placed), and thus 
giving to the under side of the detached bark and exposed alburnum, that 
pinnated labyrinthine appearance, and fancied resemblance to letters, 
which made Linné affix to one of these insects, to be presently alluded to, 
the trivial name of Zypographus. When in small numbers these larvae 
1 Linn. Trans. x. 899. 2 Trans. Ent. Soc, Lond. i. proc. 1Xxxy. 
5 Linn. Trans. x. 403. 
4 This species inhabits the Spruce-fir (Pinus nigra). —Shuckard in Loudon’s 
Mag. of Nat. Hist. 1837, p. 632. 
§ Trans. Ent. Soc. Lond. ii. proc. 1xxxii.: and iii, proe. ii, 
§ Curtis, Brit. Bat. t. G0. 
