Article beginning on page 183.
Psyche 3:183-185, 1880.

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PSYCHE.
INSECTS IN WINTER.
BY ALBERT JOHN COOK, LANSING, MICII.
THE condition of our vertebrate an-
imals in winter, and also the functional condition of their organs, have been well studied and are pretty well understood.
That most of them require more carhon-
aceous food at this season, as this milk- isters to the special kind of nutrition
which supplies animal heat, is a well rec- oguized fact. It has long been known
that some vertebrates hibernate, in which state they respire very slowly, and so
are able to live even though the heart
does circulate unoxidized blood.
The functional activity of the organs
in this case is reduced to the minimum,
and so nutrition is almost abated, and
no food is ~quired other than that stored up in the adipose tissue. But even
though these animals do lii e so slo-n ly, with too severe and long continued cold
they often lose even this little vitality and perish.
l'lq siologists have determined that
tissues snd organs, whether hi situ or
removed from the body, will maintain
their vitality for a long time. and often indefinitely, if kept in a cold atmosphere, thougli all functional actii ity is for the time held in abeyance. I myself have
exposed hens' eggs, while in the process of incubation. to a temperature but little above 0' C., until I had good reason to
believe that the hearts of the embryo
chicks had ceased tu beat. I then re-
placed the eggs under the brooding lien, when with the return of heat came also
a resumption of development. Very
likely the same explanation may rightly
account for the retarded development
in many tadpoles that pass the winter
in an immature state. Most frogs de-
velop fully in summer, and pass the win- ter in a mature state. Yet we not infre- quently find tadpoles in mid-winter, or
large ones at the very dawn of spring.
If all animals have had a common ori-
gin (and can any biologist doubt it?),
we may expect that the phenomena ob-
served among invertebrates will closely
resemble the peculiarities which we note in our study of the higher forms.
The effects of cold to stay or retard
development among insects, though per-
haps not so long and clo&ely studied as
have been the same influences as they
worked to modify development among
the vertebrates. will be found, I feel quite sure, to act in a very similar way.
The winter of 1874-75 was one of the
most severe ever experienced in the
northern United States. In the month
of February of that year, the tempera-
tnre fell below zero of the Fahrenheit
scale (- 1 i.O8 C.) , at Lansing, Michigan, twenty-one times. The mercury showed
-20' F. (-28.O9 C.) on eight different
days, and -30' F. (-34.'4 C.) twice.
Surely this was a good time to study the effects of cold upon insect life.
The codling moth insect (Cqocupsa
pomoitelld). as is well known, passes the winter, in the larval state, protected only by a slight silken cocoon, and some bark scale, 01- similar covering. The




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1 84 PSTCHE.
spring following the severe season just
spring, when birds are plenty, is found
referred to I found that nearly all these to greatly augment the destruction of
larvae that had passed the winter out
imwts.
doors about the apple trees were dead, a The late Mr. Quhby, inhis work on bee
ciwumatance I have never observed at
keeping, states that the larva of the bee- any other time.
The fht that this mop
moth, Galle~1a cereana, cannot survive
talky vaa not due to parasites, that there exposure to the cold ; that if these lw- was no climatic peculiiirity d~~rrog that vae are removed from the hive and its
winter other than the cold, especially as genial heat, (hiring the winter, they
the larvae in cellars and kitchens were
surely die. Mr. G. M. DooUttle reports
liedthy and lively, pints strong& to
that he has observed these bee-moth
the severe cold as the cause of this we]- caterpillars in exposed positions, and corned mortality.
If this inference is
that they have ~urvived even the present correct, we must conclude that iusects
rigorous winter of 1880 and 81.
1 have
which freeze up in winter may succumb
often noticed these larvae and the chrys- to very severe cold.
alids. which have passed the winter in
Farmers long since observed that cold rooms outside the hives. Still from clover sward ploughed in autnmn, and
the natural surroundings of these insects planted to corn the following spring, we may easily believe that they have was less liable to be attacked by put- developed a constitutionmoresusceptible worms, than when ploughed iu spriiig. to the cold than insects whose habits and immediately planted. This has led bring more exposure. to the very generalbelief among farmers, Mr. W. H. Edwai-ds has shown how
which view is adopted In- several iioted the development of butterflies mav be
entomologists, that exposure to the cold. retarded 1 1 ~ the cold. The bearing of
especially to alternate ft'eeziug and thaw- these experiments upon the formation of
ing, is what. destroys the cat-w~rms.
different broods of a species and charm
During the very severe winter already
teristie markings of each brood is of very referred to, 1 subjected some cutworins- peat interest.
larvae of aperies of Apotis - to iiitewe Among honey bees of the genus Apis,
cold, and to alternate cold and heat, we note peculiarities in respect to cold, which seemed in no wise to injure them, which, like their habits and instincts, ' Others were exposed very milch as they seem to separate them widely from most would be by fall ploughing, and yet other insects, and strongly remind us of passed the winter in safety. The farmers the vertebrates. Most insects freeze å´a are doubtless correct in thinking that falt in winter, so that all their functional ac- ploughing is a protection against these tivities are held in abeyance, ready to marauding cut-worms ; but wrong in start into action, at the touch of revivitr- their explanation. Exposure to insect* ing warmth, which ever comes with ivorous birds and not to m\(\ is the more returning spring.
A few of tine higher
probable solution, especially as frequent ones, really hibernate.
There is slight
cultivation of the laud in autumn aiul
activity of the tissues which is sustained



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