480 
Observations on the various Insects 
or entirely eaten out^ the skin of the wheat alone being left. One 
which I put upon a dried ear of corn immediately began to eat 
into the grain, so that in a short time it was concealed, and the 
pure whiteness of its excrement showed the goodness of its food as 
decidedly as the quantity did its rapid progress, and the celerity 
with which it was digested. On taking out the grain I found a 
hole in the top just at the base of the stigma, and on opening it 
nothing but a thick shell was left. It is a remarkable fact that 
amongst the corn infested by the caterpillars Dr. Calvert found 
numbers of the horny heads, which convinces him tliat they will live 
upon each other ; and as the heads are not merely the horny shell, 
and often have the first thoracic covering of the segment adhering 
to them, I am of the same opinion. 
These larvae have no doubt been troublesome abroad, for in a 
memoir by Dr. Herpin, he says, " At the approach of harvest I 
have found a pretty large quantity of stems of wheat which con- 
tained near to the ear, between the leaves, a thick caterpillar of 
about 2 centimetres long (nearly three-quarters of an inch), of a 
yellowish grey, rayed upon the back, and appearing to me to be 
the larva of a Noctua. This caterpillar, which is found also in the 
barns many months after the harvest, gnaws and devours the inte- 
rior of the grains of wheat, yet adhering to the ears, and deposits 
between the leaves large excrement of a whitish colour." * 
Dr. Calvert, I find, ''read a notice (before the Entomological 
Society) of the attacks of one of the Noctuidce upon the ears of 
standing corn, which led to a discussion, in which it was suggested 
that the only advisable remedy against the attacks of fresh broods 
of these insects, was to subject the land to repeated ploughings after 
the crop had been got off, and the insects gone into the earth to 
undergo their transformations, in order to expose them to the rooks 
as well as to the action of the atmosphere." f As we have seen, 
however, that numbers of the caterpillars remain in the ears, and 
are consequently stacked or housed with the grain, and fed until 
the winter, when in all probability they hybernate, any application 
to the soil in this instance would not have the desired effect. 
In what way these caterpillars undergo their transformation to 
the chrysalis state is uncertain ; if it be in the refuse chaff, then 
those which are housed in the barn may escape in the chinks of 
the floor and round the walls, or as they are very active, and great 
ramblers, as all caterpillars are when they are about their final 
change, they may succeed in getting out of the building at the ap- 
pointed season, and secrete themselves in herbage or in the eartli, 
to become chrysalides; and of course those which inhabit the 
* Extract from the Memoirs of the 'Sec. Royale et Centrale d' Agricul- 
ture,' for 18-12, p. 29. 
I- Trans. Ent. Soc, vol. lii., p. xxxv. 
