Milford chronicle., 1926-05-28
COOLING MOTH CONTROL
BY DIR. H. l.. DOziar, EntOmOligist

by Dr. IL. l.. DOzlar' EhuOHOlels'
The 1925 commercial production
of apples in Delaware amounted TO
34O. 900 barrels and the total farm
value of this crop was of an esti-
mated value of $1,690,00O. The
season of 1925 was an unusually
favorable one for the development
of the Cooling Moth in most of the
apple growing regions and espec-
tally was this true of Kent County,
Delaware, where an enormous toll
was eXacted.
From the abundance of overWin-
tering worms in the packing house
and from the present variable
weather conditions, everything
seems to indicate a bad Cooling
Moth year this season unless active
measures are taken at once to COM
bat this pest. 1t is a well known
fact that a long wet season is fav-
Orable for the development of fun
gous diseases and the reverse has
been proven true in the case of the
Cooling Moth.
Generally it seems true that
temperature conditions governing
the blooming period also govern
and regulate the appearance of the
Spring brood moths. A favorable
season, the initial carry-Over in
festatiOn, and the thorOughness of
spray procedure are all vital, i'm
pOrtant factors. Under outdoor
conditions at Newark about SO of
the Over-wintering worms had con-
or fhni,. on, orUonpo f1rhac ar11
changed to the pupa Oast stage in
development before the moth) on
May 5th and in collecting several
hundred worms in a packing house
near Dover May 7th only a single
pupa was found. This would ildi-
cate a much belated issuance of the
adult moths this season.
The eggs are laid mostly upon
the foliage and in about ten days
after reposition, Matching starts
1t has been proven quite conclu-
sively that the adult moths deposit
eggs only when the thermometer
registers go degrees or above fOuI
o'clock in the afternoon or in the
evening, during which time. the
moths are actively flying. AS from
20 to 500 of the newly Matched
worms try to enter the fruit from
the calyx or blossom end, great
emphasis should be placed on sufi-
cient and thorough liquid spraying
under strong pressure for the caly2
or petal fall application. Starr
when two-thirds of the petals have
fallen, using from ten to twelve
pounds of dry lead arsenate to the
200 gallon tank, and in cases oi
very heavy infestation and damage
last fall, it would be highly advis-
able this season to start a little
earlier and apply two calyx sprays
which would allow more thorough
cOVerage of the calyx cups for all
the varieties in the mixed orchard
Remember that a thorough calyx
application is vital and will elimi-
nate greatly the necessity of late
spray applications, with their con-
seGuent danger of overdose spray
residue. Wherever inYestigational
work has been carried out, either
by the Government Bureau or the
State Experiment Stations, every
thing eventually goes back to a
LAO1 OuSA SOullO VI VI lld llISb DlOOus
Concentrate your effort on a COM
plete control of the first Spring
brood of worms. If slip-shod, in
efficient spray methods are used
and a large number of first brood
worms be allowed to reach matur-
ity and deposit eggs, then it can
readily be seen that the very best
of spraying in the later applica-
tions can only result in a partial
control and at the most there will
be a large percentage of stung fruit
and drops.
The writer strongly advises the
use of a single straight nozzled
spray gun from beneath the tree
together with a rod or spray gun
from the tower on the older trees
and especially for the calyX appll-
cation where a high strong pres
sure is necessary to shoot the spray
into the calyx cup. A fine floating
mist spray does not fill the calyX
CUPS with as thorough a coating OF
lead arsenate as is necessary.
Recent experimental data tends
to indicate that the addition OF a
caseinate spreader is more essen
tial in the calyx application than IL
the later sprays. More than twice
&C much arsenic was found by Dr
smith of California in the calyces
where a casein spreader was useu
.oThe spreader tended to cause
1,ttIe nond of spray to form aro1nC
49, hoses of the stamens and caIyA
Cno -, o.oos without the spread
tTO'tt eT the spray tended to collect II II
drops and run off" 1t has 80 aiSt p
been shown that spreaders are 20 y.
more Importance IN spraying niDs - r.
der der windy conditions as 1t helps u
eeav"nt uea the tendency Of the spray
to p1econie Collect in droplets and run on,
10 Use ser from two to three G, cove tSl
sprsy spTsy'' schedule as outlined in tn th'
Spray SPTsy Circular issued by the Uni
versity Experiment Stauon-