THE INFLUENCE OF TEMPERATURE ON THE PHENOLOGY OF THE TORTRICID MOTH
ARCHIPS ROSANA L. (LEPIDOPTERA: TORTRICIDAE)
IGOR Y. GRICHANOV, OLGA N. BUKZEYEVA AND KSENIA V. ZAKONNIKOVA
All-Russian
Institute of Plant Protection, VIZR
St.Petersburg-Pushkin 189620 Russia
Based on the data on phenology of Archips rosana
L. known from
literature, field studies were conducted during the definite
periods
of the pest development in the Azov district of the Rostov area.
The
influence of the temperature factor on the embryonic development
of
A.rosana was determined by the technigue of the Holland workers Minks
and De Jong (1975) who found a strong linear correlation between
the
mean daily temperature and the proportion
of eggs hatched in
Adoxophyes orana F.v.R. The results of
our studies show that the
computer program developed for A. orana can be also used for computer-
based prediction of egg hatching in A. rozana.
KEY WORDS: Archips rozana, Tortricidae, orchards, Russia
INTRODUCTION
The tortricid moth Archips rozana L. is a broad-spectrum
polyphage
damaging almost all deciduous tree and
shrub species in many
countries of Europe and Palearctic Asia (Vasiliyev, Lifshitz,
1984).
It is most destructive in orchards of
South Russia, Ukraine and
Moldova (Pralya, 1992). It is a monovoltine species
with obligate
diapause. Its eggs overwinter in egg-masses on smoth parts of bark
of
trunks and main branches of trees, and in the lower part of the
most
thick branches of berry shrubs. The average number of eggs in the egg
-mass is 46 and the average survival of eggs during the
winter is
50%, with the hatching rate being highly variable (Miniailo
et al.,
1990).
The economic damage threshold of A. rozana
has been considered
more or less well defined both from egg-mass counts in
autumn, and
from number of young larvae in inflorenscences in
spring (Bychko,
1970; Vasiliyev, Lifshitz, 1984; Skliarov,
1986). However, the
question of optimum dates of fruit-tree protection in early
spring
remains open, especially as it
concerns the use of computerized
systems in pest and disease prediction (Grichanov,
Karpilovsky,
1991). Thus for example, Garnaga and Chernyi (1981) recommended
that
apple trees should be sprayed with insecticides at the
overwintered
egg hatch of 30%, that is before blooming,
whereas Pralia (1992)
considered it better to be done after blooming, explaining it
by the
fact that larvae have no significant
influence on quantitative
indices of yield before fruit start growing. The influence
of mean
daily temperatures on the dynamics
of egg hatching was not
investigated.
MATERIAL AND METHODS
Our aim was to clarify the phenology of A. rozana on the basis of the
pest and weather monitoring in the study area and to
identify the
weather parameters to be used as predictors
in a model permitting
computer-based warning of attacks of the damaging
stage of this
species. The field work was carried on
in the laboratory located
within the territory of the Vinogradar state farm (Port-Katon,
Azov
district, Rostov area, North Caucasus) in 1993.
Weather conditions were monitored
using the Austrian KMS-P
station that recorded the main weather data each our and produced the
information summaries over 24-hour periods. In addition,
the KMS-P
station provided effective temperature sums and daily rates
of egg
development and hatching computed from daily temperatures (Minks,
De
Jong, 1975).
Based on the data on phenology
of this pest known from
literature, we could do our field work during the definite periods
of
the pest development.
The studies were conducted in two blocks of a young
apple orchard
predominated by winter varieties of
Malus domestica L. (Red
Delicious, Corey, Semirenko and Aidored); in
an alycha orchard
(Prunus devaricata Ldb.: Rumianoye Yablochko,
Dessertnaya and
Obilnaya), and in a plum orchard (Prunus domestica L.:
Renclaude,
Altana, Vengerka and others).
The dynamics of moth flight was studied
using pheromone traps
from June 7 to August 5. The technique
of trap installation and
operation was as recommended by the current practical manuals.
At
first insects were sampled once a day, and later (after
first moths
were trapped) 1 or 2 times a week. Sticky bottoms were
changed as
they bacame dirty.
Egg hatching estimations were made in spring from
April 27 to May
9 in the alycha orchard where the
density of egg-masses was the
highest. For this purpose, 2-m long sections of main branches of each
of 20 or 30 trees were thoroughly examined
for egg-masses and at
least 10 egg-masses were brought to the laboratory where
they were
examined under microscope for eggs hatched. These eggs can be
easily
distinguished by exit holes of larvae. The data on egg hatching
were
compared with weather data provided by the KMS-P station.
RESULTS AND DISCUSSION
The influence of temperature on embryonic development of
A. rozana
was estimated by the method suggested by Minks and De Jong (1975) who
found a strong linear correlation between the mean daily temperature
and the proportion of eggs hatched in Adoxophyes orana.
Using the
initial data of the above authors we made the following
equation of
regression (r = 0.997):
Y = 0.996 X - 8.98 _+ .0.197,
where X - mean daily temperature, Y - expected
proportion of eggs
hatched.
To test the program stored in the memory of the
KMS-P station, we
compared the output data (mean daily temperature
and proportion of
eggs hatched) for the period of April 27 - May 9.
The resulting
equation of regression (r = 0.947)
Y = 0.956 X - 8.22 _+ .0.620
is not very different from the above. The difference is probably
due
to rounding error.
The actual relation between the proportion
of eggs hatched in A.
rozana and the mean daily temperature was as follows (correlation
of
medium strength, r = 0.558):
Y = 1.110 X - 10.82 _+ .2.931.
Here the regression line has a more gentle slope,
but taking into
account the larger standard error for Y and
a small number of
observations, we can conclude that mean daily temperature is of about
equal importance in determining the egg hatching
dynamics in A.
rozana in spring and A. orana in summer.
Further regression analysis was
carried out by accumulated
totals. The actual proportion of eggs hatched from the
overwintered
egg-masses of A. rozana almost completely agreed with the
estimated
values of eggs hatching dynamics (r = 0.993).
We also compared the accumulation
dynamics of effective
temperature sums above 10 'C and the proportion of eggs hatched.
For
A. orana the regression equation for the proportion of eggs
hatched
(Y, estimated) based on the actual sum of effective temperature
(X)
is:
Y = 1.066 X - 3.69 _+ .0.795 (r = 0.999),
and for A. rozana (observed data):
Y = 0.958 X - 1.19 _+ .2.406 (r = 0.994).
In both cases the regression lines appeared to be
practically the
same. So, the sum of effective
temperatures can also be used to
estimate the proportion of eggs hatched (%).
The duration of periods of egg hatching
varies with temperature
and is one of the factors determining
the number of chemical
treatments. Despite the differences in biology between A. rozana
and
A. orana, their egg development conforms to common rules (Table 1).
The experts from the Plant
Protection Institute in Vienna
(Austria) have shown that the relation
between temperature and
embryonic development dates found for A. orana in Holland (De
Jong,
Minks, 1981) is also suitable for practical use in Germany, Austria,
Yugoslavia and other countries (KMS-P, Concise specification,
1991).
The results of our investigations show
that the computer program
developed for A. orana can be also used for computer-based prediction
of egg hatching in A. rozana and, possibly, some other
leaf-rollers
occuring in Priazovye area. The minimum night and the
maximum day
temperatures can be also used for this purpose. The Holland
workers
De Jong and Minks (1981) suggested a simple method to determine
the
rate of egg-development of A. orana per 24 hours
(Fig. 5 in cited
paper).
However, the practical use of
the station for warning purposes
can vary with phenology of these two tortricid species. Daily
counts
of egg hatch in A. orana should be started from the beginning
of the
stable flight period or from the peak of the flight as recorded
with
pheromone traps (Minks, De Jong, 1975). In contrast to
A. orana, A.
rozana overwinters as egg, so the
readings taken from the
agrometeorological station in early spring
before the sum of
effective temperatures reaches 20 'C do not represent the
real egg
hatch but favourable conditions for embryonic
development of the
pest. Once egg hatching began, the observed and estimated
data were
practically coincident, and the timing of control (if necessary)
of
both A. orana and A. rozana is based on mass
egg hatching (the
optimum control dates recommended by the Austrian KMS-P
station are
those when the accumulated total is equal to 100%).
Automatic calculation of effective
temperature sums continued
until the end of A. rozana flight (Table 2).
Comparison of the
observed and literature data has shown that the development threshold
of 10 'C is quite suitable to be used in warning on the phenological
events in A. rozana. The
use of this threshold seems justified
because most automatic agrometeorological stations are programmed for
at least several pest species,
and one threshold for all makes
practical prediction more convenient.
In orchards of Port-Katon increased
moth catches in pheromone
traps were recorded in alycha (3 males per trap a day) with two peaks:
on June 18 and July 20. In the apple
and plum orchards the male
catches did not exceed one moth per trap, with no second peak at all.
A sharp decrease in moth flight in all orchards after June 22 can be,
possibly, explained by lowered temperatures and more
rainfall at
night. However, our special investigation
could not reveal any
significant relation between these factors.
Thus, during the studies conducted
in 1993 a rapid method for
monitoring A. rozana on the basis
of automatic recordings of
meteopredictors has been tested. It has been shown that
the warning
program for A. orana stored in the
Austrian agrometeorological
station KMS-P needs only minimum updating to be used
for phenology
prediction of A. rozana in the steppe zone of North Caucasus.
The
sums of effective temperatures above the threshold of 10 'C are quite
suitable for monitoring the phenological phases in A. rozana.
References
Bichina, T.I.; Goncharenko, E.G.: The orchard leaf-rollers and
their
entomophages. Kishinev, 1981, 150 S. (in Russian)
Burkova, L.A. Resistance of orchard leaf-rollers and its overcoming.
Avtoreferat diss. kand. biol.
nauk, Leningrad, 1970, 18 S. (in
Russian)
De Jong, D.J.; Minks, A.K.: Studies on Adoxophyes orana,
the major
leafroller pest in apple
orchards in the Netherlands. Mitt.
Schweiz. Ent. Ges. _54. (3) (1981), 205-214
Egurasdova, A.S.; Poliakov, I.Y.: Phytosanitary
diagnostics and
forecasting in modern plant protection. Moscow,
VINITI, 1990, 56
S. (in Russian)
Garnaga, N.G.; Chernyi, A.I.: The tortricid moth
Archips rozana.
Zashchita Rast. _5. (1981), 39 (in Russian)
Grichanov, I.Y.; Karpilivsky, L. N.: Computer-based
approach to
collection, handling and use of information
for forecasting and
warning the occurence of crop pests. Agrometeorol.
Res. i Prod.
Prots. v Rast., Kiev, 1991, 147-149 (in Russian)
KMS-P Agrometeorological Station, Concise specification, Graz,
1991
Miniailo, V.A.; Miniailo, A.K.; Poiras, A.A.; Shaplyko, Y.S. Seasonal
dynamics of flight into traps baited with synthetic
sex pheromone
in Archips rozana. Integr. Zashch. Selsk.
Rast., Kishinev, 1985,
53-57 (in Russian)
Miniailo, V.A.; Miniailo, A.K.; Tuganov, S.P.; Poiras,
A.A.: To the
assessment of survival and causes of overwintered
egg losses in
Archips rozana. Ekologiya _5. (1990), 41-46 (in
Russian)
Minks, A.K.; De Jong, D.J.: Determination of
spraying dates for
Adoxophyes orana by sex pheromone traps and temperature
recordings.
J. econ. Ent. _68. (5) (1975), 729-732
Skliarov, N.A.: Economic efficiency of
the shortened program of
chemical pest control in commercial apple orchards.
Sadovod. i
Vinograd. Moldavii _10. (1987), 50-52 (in Russian)
Vasiliyev, V.P.; Lifshitz, I.Z.: Pests of fruit crops. Moscow, Kolos,
1984, 399 S. (in Russian).
_Table 1. The dynamics of egg hatching in Archips rozana as observed
in
the orchard and predicted by the
KMS-P station (Rostov area,
Port-Katon, 1993)
_____________________________________________________________________
Proportion of
Sum of
Minimum Maximum Mean overwintered
egg
Sampling effective daily
daily daily hatch in the pest
date tempe-
tempe- tempe- tempe-
(accumulated
ratures
rature rature rature
total in %)
___________________
Observed Predicted
_____________________________________________________________________
27.04 21
5.9 18.4
12.15 20.3 17.4
28.04 25
10.3 19.3
14.8 23.3 22.9
29.04 29
9.3 16.9
13.1 26.6 27.9
30.04 33
5.6 18.5
12.05 29.5 31.7
1.05 37
8.5 18.5
13.5 32.7 35.4
2.05 42
11.2 18.5
14.85 37.5 41.3
3.05 49
12.5 21.4
16.95 43.4 49.2
4.05 56
9.9 23.4
16.65 54.6 56.7
5.05 64
11.9 22.4
17.15 60.5 65.7
6.05 72
6.5 24.0
15.25 72.0 71.8
7.05 80
13.4 22.5
17.95 77.95 *) 81.3
9.05 89
6.8 19.1
12.95 79.8 *) 91.0
_____________________________________________________________________
*) With egg losses taken into account: warm
dry and windy weather
during the first 10-day period of May contributed to drying up of egg
-masses, especially along the edges of small egg-masses.
_Table 2. Sums of effective temperatures for development
stages of A.
rozana (Rostov area, Port-Katon, 1993)
_____________________________________________________________________
Sums of effective temperatures for each stage
Date Development _____________________________________________
stage
Observed data Literature
data *)
(threshold of 10'C) (threshold of 8'C)
_____________________________________________________________________
27.04 First records
21
25 - 57
of eggs hatched
4.05- Mass egg
49 - 72
58 - 70
5.05 hatching
5.06 Beginning of
256
274 - 289
pupation
14.06 Beginning of
340
310 - 410
moth flight
27.07- End of moth
813 - 864
649 - 880
31.07 flight
_____________________________________________________________________
*) Bychko, 1970 (South Ukraine);
Bichina, Goncharenko, 1981
(Moldavia); Miniailo et al., 1985 (Moldavia); Burkova, 1988 (Crimea);
Pralia, 1992 (Krasnodar Territory a.o.).