CHA. CII. SALICA CEH. . SA‘LIX. 1481 
Baxter, several of the species are in some seasons almost entirely destroyed 
bythe Cryptorhfnchus lapathi. Mr. Baxter, jun., informs us that the species of 
willow which are least injured by this insect are, the S. pentandra, S. deci- 
piens, and S. nigricans. After the wood in the trunk of the tree is partially 
destroyed, it is generally found infested by the black ant (Formica fuligindsa 
Latr.), which is found, not only in the wood of the willow, but in that of other 
decayed trees, even in houses, living on the decayed rafters and wooden 
floors. In Kirby and Spence’s Entomology, these insects are described as living 
in societies, and “ making their habitations in the trunks of old oak or willow 
trees, gnawing the wood into numberless stories, more or less horizontal, the 
ceilings and floors of which are about five or six lines asunder, black, and as 
thin as card; sometimes supported by vertical partitions, forming an infinity of 
apartments, which communicate in some places by small apertures; and at 
others by light, cylindrical pillars, furnished with a base and capital, which are 
arrayed in colonnades, leaving a communication perfectly free throughout the 
whole extent of the story.” (Kirby and Spence’s Introd., &c., i. p. 483.) 
By far the most valuable species of willow in English woods, as already 
stated, is S. caprea; and on this the Trochilium crabroniférme, or lunar hornet 
sphinx, feeds, in its larva state, upon the living wood, by boring into the trunk, 
and thus destroying the tree. An account of this insect has been communicated 
to the Magazine of Natural History by the Rev. W. T. Bree, of which we give the 
following abstract :—“TIn the Transactions of the Linnean Society, vol. iii. tab.i., a 
figure of the Tro- 
chilium crabroni- 1290 
forme (jig.1290.), 
under the name 
of Sphinz crabro- 
niformis, is given 
in its three stages. 
Lewin, the writer 
of the article, 
gives it as his 
opinion that ‘ the 
caterpillar does 
not enter the . 
wood till the second year of its own age;’ and he states as a reason, that, 
‘among all the numerous larve he has found from June to November, he 
could perceive but a slight difference in size. Possibly, therefore, they may 
feed on the tender bark of the sallow root the first year after they are 
hatched.’” This, Mr. Bree thinks, is very probably the case; for he adds that 
he has not observed in the wood any perforations of a very small size, or 
such as have the appearance of having been made by caterpillars newly 
hatched. As the caterpillar eats its way upwards through the solid wood, a 
question may arise: How is the sphinx, when it bursts from the chrysalis, 
to make its escape out of the wood without injury? To obviate this diffi- 
culty, instinct directs the caterpillar, before it changes to a chrysalis, to turn 
its head downwards, so as to be opposite to the orifice, which affords a ready 
exit for the winged insect. A portion of the plate in the Linnean Transac- 
tions above referred to is copied in fig. 1290.; in which a is the male imago, 
or perfect insect ; 6, the female imago: and in fig.1291.; in which c is the larva, 
or caterpillar, in its proper situation, with its head upwards, in the act of feeding 
on the wood; d, the pupa, with its head downwards, preparatory to its exit ; 
and e, the web closing the orifice by which the larva had entered, and by which 
the imago must come out. Mr. Bree sent us the butt ends of three young willow 
trees, which had been perforated by the insect, as shown by a view of their ends 
given in fig. 1292. One of these, on being split up, presented the appearance of 
Jig. 1292. a; and, as it did not then include the case of the pupa, we conclude 
that the insect had escaped. The insect enters the stems, which it perforates 
near the root, and eats its way upwards for several inches,sometimes to the length 
