20 
THE ENTOMOLOGIST’S WEEKLY INTELLIGENCER. 
who operated upon the tree said he was 
almost stifled when he first intruded on 
their privacy. — J. R. Hind, 22, Grove 
Road, St. John’s Wood ; April 13. 
Zeuzera AEsculi. — I am able to con- 
firm a statement made some time since 
by one of your correspondents, that 
Zeuzera j^sculi continues more than 
one year in the larva state. The eggs 
hatch in about three weeks, the larvae 
remaining small during the first year. 
In the second year, when the imago is 
out, they are about half-fed, and I sus- 
pect make their appearance in the per- 
fect state generally in the third year : 
on this point, however, I cannot speak 
with certainty. In July, 1859, many of 
the imago were found on some, lilacs and 
thorns in this neighbourhood : late in 
the summer small larvae were boring the 
trunks and branches of the same trees, 
and in July, I860, were still at work, 
much larger, though yet far from their 
full growth. I have not examined the 
trees since, but expect to find pupae 
when I do so. These larvae I believe are 
not in the habit of congregating to the 
same extent as those of Ligniperda. — 
Ibid. 
Larvce of Cossus ligniperda. — , Often in 
former years have 1 seen five or six 
empty pupa-skins of Cossus projecting 
from an old willow tree, and supposed 
only that the same number of larvae had 
fed and changed in the trunk, the sole 
enquiry as far as I recollect that arose 
in my mind being how it was known 
that the larva of Cossus lived three years 
before it changed to a pupa, for so went 
the family tradition. Later, when I 
took to collecting the Coleoptera that live 
under bark, these Cossus larvae came 
oftener under my closer notice, and I 
then found that not only were they of 
gregarious habits but that the individuals 
of the communities were of widely dififer- 
ent sizes, and as I presumed of different 
ages. As your correspondent, W. T. R. 
(ante p. 14) states, of the lot to which 
his attention was directed, there were 
always three sizes ; thus perhaps the 
idea arose that the insect exists three 
years in the larva state. It was all but 
certain that those which were two and a 
half inches long would become pupae and 
be perfected in the next season. It was 
reasonable to believe that those an inch 
and a half long would not be ready to 
change for a year after that, and that 
the little ones were still twelve months 
younger; but this was only a reasonable 
supposition. Further, although we know 
that in some species of moths, the cater- 
pillars of one brood when external feeders 
sometimes vary extremely in their de- 
velopment, so that some become perfect 
insects many months before the others, 
yet I doubt if the three sizes of Cossus 
larvae now under consideration were pro- 
duced from one batch of egg. Rather I 
think there were three generations of 
parents, but this is also only a supposition. 
The larvae of Cossus are found in various 
trees ; willow, birch, alder, elm and oak 
being the favourites, and it is only in old 
settlements that their presence becomes 
known by the damage done to the tree, 
the wood in such cases being riddled 
through and through, and, the bark being 
detached, the ruin effected becomes ap- 
parent. Many a fine old tree is killed 
by these larvae : I know one oak, known 
as “ the spectre oak,” which has gradu- 
ally been despoiled by these cave- 
making robbers, and now holds its bare 
arms aloft as if invoking punishment on 
its destroyers. But when the colony of 
larvae is young there is very little out- 
ward and visible sign of the destruction 
going on within, yet when the informed 
entomologist pulls off the scarcely 
loosened bark, the associations of the 
marauders are apparent. — J. W. Doug- 
las, Lee; April 16. 
