Last summer I discovered, unfortunately too late, that a large _Cossus_
was working in some large and very old Oak trees near here. I hope
next June or July to find out what it is, as I shall construct nets to
envelop the tree trunks of several of these so infected Oaks. None of
my correspondents have been able to give me light on the subject; they
think it possible that this is a new species, and urge close observation,
advice which I hope to be able to follow.
I also purchased five large trees of a coarse variety of Poplar, known
here as Cottonwood, that were to be cut down, as they had commenced
dying, “caused by a _grub_ working in them.” I found it to be a _Cossus_
larva, but not as large as that working in the Oaks. Judging from a
comparison of the empty pupæ cases found in them, which in these Poplars
were very numerous, it is not the one described by Mr. Bailey in last
January number as “_Cossus centerensis_” but seems more like _Xystus
robiniæ_. I had three of the trees cut down in order to obtain the pupæ;
judge of my surprise and disappointment when my man came in, telling me
he could find _none_ but “lots of nasty _grubs_, of which he had given
the near chickens probably a hundred or more,” not thinking them valuable
to me. I sent him back with instructions to preserve every larva he could
find, and I now have about fifty in every stage of development from the
half-inch beet red, the nearly two-inch long pink, to the about two and a
half-inch long greenish-white larva. I have some in the wood in their own
burrows, and have put the rest in sawdust; and I have ordered him to cut
me pieces of that wood, bore some holes in the ends and put in the other
larvæ, and cork it in, leaving a few air-holes; with these I hope to
complete my observations in a warm room. I did not know before that these
hybernated in the larval state, much less did I think they would be found
of different moults.
A. H. MUNDT, Fairbury, Ills.