The daily star-mirror. (Moscow, Idaho) 1911-1939, 1921-05-07
C0DL|N.MOTH' STUDIES:
ARE REPORTED
VALUABLE INFORMATION FOR
GROWERS RESULTS FROM IN
vESTIGATIONS AT PAYETTE


The codlin-moth Investigations Of
1920 by L. E. Longley, associate hor.
ticulturist of the Idaho Agriculture.
Experiment Station, were the direct
outcome of a request Of a group Of
fruit growers to the farm bureau OF
Payette county during the 1919 state
horticultural meeting held in Paw
cite. The report of the work in the
Payette section for 1920 can be
grouped under three heads:
1. A study of the different phases
of the life history of the Goblin moth.
2. Observations on the manner and
effectiveness of spraying operations.
3. Experiments to determine how
many sprays are necessary efficient
ly to control the insect
observation points for studying the
life history of the moth were located
all the way from New Plymouth to
Weiser. Over twenty orchards were
used for various phases of the work.
Close watch was kept of the various
stages Of the insect in cages where
the development could easily be
studied. This was supplemented by
observations in the orchards.
This study revealed the fact that
the first brood of moths emerged over
a long period, there being really two
peaks to the brood, one about June
II and the other approximately July
l, as indicated in the table that fol-
lows. The data in this table repre-
sent the number of moths emerging
for each week from the time they be-
gan until all were emerged. Thirty
five trees were under daily observ-
alton, these trees being scattered
thruout the valley:
Emergence of First Brood of Cod
lin Moth, 1920.
Summary of Data for Payette VAL
ley, by Weeks.
May 1929, 1; May 80 to June 5, 4;
June 6-12, &c; June 1919, 81; June
20-26, s; June &c July 1, -; July
2-8, %; July 9-15, 2.
Observation on the manner of
spraying in vogue in the average
fruit orchard showed that there is
urgent need of more thoro and careful
spraying. The most common fault is
that of not covering the apples with
spray on all sides Of the fruit. If a
portion of the apple. is left uncovered
the newly Matched worm is likely to
find that spot and enter The need
vas apparent for careful experiments
along the line of using some material,
probably soap, in the lead spray to
make it spread more evenly, thus en-
surfing thoro covering by the poison.
The experiments on number Of
sprays studied in connection with the
ife history of the moth in 1920, indi-
ate that five sprays are necessary,
IS follows: =,
l. Calyx spray. {
2. One spray coming just before !
he peak" of the first brood.
8. Another spray about three i
weeks later to cover the latter part c
f this brood. a!e
4. A spray just as the first worms
f the second brood are Matching.
s. Another spray two to three
7eeks later. =
In seasons with continued warm
,eather in late August and Septem-
er, possibly an additional spray
7ould be of value in controlling late S
1orms, which often are entering just
efore picking time. The observation
nd experiments indicated that in
ONE orchards one or two of these a
prays might be profitably omitted,
rovided that close watch had been j
ept on the stages of the insect from
arly spring. Considerable data COW b
ring period of years for each To-
llity should be accumulated to throw
ght on this point. al