The anti-monopolist., 1877-05-31
From the Scientific American.
EXPERIMENTS WITH THE LOCUST
EGGS.
BY PROFESSOR C. V. RILEY.


There are many questions respecting |
the manner in which the eggs OF the |
Rockey Mountain Locust are affected |
under different conditions. which are |
of intense practical interest, and which |!
are frequently discussed with no def
mite result being arrived at, or no pos |
tive conclusion drawn. Such are, for
instance, the influence of temperature,
moisture, and dryness upon them; the
effects of exposing them to the air, OF
breaking open the pods, of narrowing
or blowing them under at different
depths, Of tramping upon them. Ev-
erything, in short, that. may tend to
destroy them or prevent the young To-
Gusts Matching, is of vital Importance.
With a view of settling some Of these
questions, and in the hope Of reaching
conclusions that might prove valuable.
have carried on during the past win
ter a series of experiments which will
be reported in detail in my 9th report,
and the conclusions drawn from some
of which l give you herewith:
Nine experiments, tot test the effects
of alternately freezing and thawing,
showed that: lst, the eggs are Tar less
susceptable to alternate freezing and
thawing than most of us, from analogy,
have been inclined to believe. Those
who have paid attention to the subject
know full we'll that the large proper
ton of insects that hibernate on or in
the ground are more injuriously affect
ed by a mild, alternately freezing and
thawing winter, than by steadily cold
and severe one; and the idea has quite
generally prevailed that it was the
same with regard to our locust eggs.
But if so, then it is more owing to the
mechanical action which, by alternate
expansion and contraction of the soil,
heaves the pods exposes them, than to
the effects Of the varying tempera-
lures. 2nd, that suspended develope-
ment by frost may continue with
impunity for varying periods, after the
the embryon is fully formed and the
young insect is on the verge Of hatch
ing. Many persons, having in mind
the well known fact that birds eggs
become added ifincubatiOn ceases be-
fore completion when once commenc'
ed. would. from analogy, come to the
same conclusion with regard to the To-
Gusts eggs. But analogy here is an
unsafe guide. The eggs Of insects
hibernate in all stages of embryonic
development, and many of them with
the larva fully formed and complete
within. The advanced development
of the locust embryo, frequently no
ticed in the fall. argues nothing bu1
very early Matching as soon as spring
, opens. Their vitality is unimpairet
by frost.
, A series of sixteen experiments, tt
, test the influence of moisture upon th'
eggs. establish a few facts that wer'
. somewhat unexpected. / give one o
the experiments as sample. The in
sect is denizen Of the high and ari'
: regions of the northwest, land has oftel
o been observed to prefer dry and sunni
4 places, and to avoid wet land, for pun
j. poses of oviposition. The belief tina
: moisture was prejudicial to the egg
Q has, for these reasons. very general
e prevailed. The power which they e,
). hibit of retaining vitality and
q Matching under water or in Saturate
J. ground is. therefore, very remarkabl
70 the more so when viewed in cOnne'
Is ton with the results obtained in th
10 succeeding experiment. That tn
I eggs should hatch after several week
ar submergence, and that the young il
ir sect should even throw off the; pos
,e natal pellicle (dmbiou) was to me quit
10 a surprise. and argues most wonde
8 full tOughness and tenacity. Aft'
of being dried and soaked for over 81
weeks, under conditions that approat
le to those of spring. l found a good pr
of portion of the eggs to contain fu
r. formed and living young larv;
NJ which. though somewhat shrunke
SO and evidently too weak to ha,
an made their exit. were still cab
ad BILE of motion. The water evident
yh retards Matching. An examination
5h the submerged egg that remained u
re Matched. long after others had hatch'
,lv which had been under similar tres
tn ment UP to a certain time and tn
he transferred to earth, showed the ja'
.n and tibial spines to be still quite so
re- 1t is. therefore. in preventing t
at proper hardening of these deliveri
ri. points that water doubtless retar
he the Matching, and preventg its acco
rs plishment long before the embry
et. perishes. Yet, when once life h
sat gone. the egg would seem to rot quie
al er in the water than in the ground.
Ire The experiments. further. pro
of conclusively that water In winter tin
er, when subject to be frozen, is still Il
Jon injurious to the eggs. Altogeth
,ne these experiments give us very lit
are encouragement as to the use OF wa
ed. as q destructive agent; and we {
MS readily understand how eggs n
INV hatch out.as they have been known
lor- do. in marshy soil. or soil too wet
on the plow. or even from the bottom
hey ponds that were overf1owed dur
nib winter and spring. The only insta
eat in which water can be profitable u
ocx :. ~-l,o~o -, 1ond con no flooded f(