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PERFORMANCE OF THE CABBAGE APHID BREVICORYNE BRASSICAE (HEMIPTERA: APHIDIDAE) ON CANOLA VARIETIES

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The cabbage aphid Brevicoryne brassicae L. (Hemiptera: Aphididae) is one of the most abundant canola pest insects, causing economic damage to flowering and podding crops. Cabbage aphid performance (abundance, fecundity, development, longevity and generation time) in canola, juncea canola, and canola-mustard was studied under glasshouse conditions. The three canola varieties tested in this study are highly susceptible to cabbage aphid damage. There were no significant differences between canola-mustards and conventional canola in attracting cabbage aphids. Twenty one days after the initial aphid infestation, numbers of winged adults and wingless adults were similar among the canola varieties (p>0.05). Within a Brassica variety, cabbage aphids responded differently to plant parts. In the life table study, there was a significant difference in fecundity (p=0.04), finite rate of increase λ (p=0.048) and doubling time DT (p=0.032) of cabbage aphids reared on mature leaves among the canola varieties. The highest fecundity (55.93 ±3.35 nymphs/female) and intrinsic rate of increase rm (0.364±0.013) were observed on canola-mustard. However, no significant differences were found in the nymphal development period, longevity, survival and mean generation time of cabbage aphids on the canola varieties tested. Assessing the ability of mustard and canola varieties to resist aphid infestation in the drier and warmer regions of Australia is critical with new canola varieties being released, and the increasing climatic variability in the cropping regions of NSW due to human-induced climate change.
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PERFORMANCE OF THE CABBAGE APHID BREVICORYNE BRASSICAE
(HEMIPTERA: APHIDIDAE) ON CANOLA VARIETIES
!
Minh Hoang Gia1*and Nigel R. Andrew1
1Insect Ecology Lab, Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, 2351, Australia
*Present Address: Vietnam Academy of Agricultural Sciences, Hanoi, Vietnam
Email nigel.andrew@une.edu.au
Summary
The cabbage aphid Brevicoryne brassicae L. (Hemiptera: Aphididae) is one of the most abundant canola pest insects, causing
economic damage to flowering and podding crops. Cabbage aphid performance (abundance, fecundity, development, longevity
and generation time) in canola, juncea canola, and canola-mustard was studied under glasshouse conditions. The three canola
varieties tested in this study are highly susceptible to cabbage aphid damage. There were no significant differences between
canola-mustards and conventional canola in attracting cabbage aphids. Twenty one days after the initial aphid infestation,
numbers of winged adults and wingless adults were similar among the canola varieties (p>0.05). Within a Brassica variety,
cabbage aphids responded differently to plant parts. In the life table study, there was a significant difference in fecundity
(p=0.04), finite rate of increase λ (p=0.048) and doubling time DT (p=0.032) of cabbage aphids reared on mature leaves among
the canola varieties. The highest fecundity (55.93 ±3.35 nymphs/female) and intrinsic rate of increase rm (0.364±0.013) were
observed on canola-mustard. However, no significant differences were found in the nymphal development period, longevity,
survival and mean generation time of cabbage aphids on the canola varieties tested. Assessing the ability of mustard and canola
varieties to resist aphid infestation in the drier and warmer regions of Australia is critical with new canola varieties being
released, and the increasing climatic variability in the cropping regions of NSW due to human-induced climate change.
Key words life table parameters, canola-mustard, climate change, plant structure
INTRODUCTION
Among the various insect pests invading Brassica
crops, the cabbage aphid Brevicoryne brassicae L.
(Hemiptera: Aphididae) is considered one of the most
destructive, being widely distributed in temperate and
warm regions around the world (CABI 2013). Aphids
transmit 50% of all insect-borne plant viruses (Nault
1997). Virus transmission is increasing with warming
conditions and changing precipitation regimes (Finlay
and Luck 2011). With the Australian continent
warming by 0.75°C since 1910 (CSIRO-ABM 2012),
and predictions for a dryer continent by 2030 (CSIRO
2007), it is important to understand the effects on
population dynamics (Andrew 2013) including at the
microclimate level (Andrew et al. 2013a). Also
understanding changes in nutrition for different plant
varieties is critical in studying associated pest species
(Nguyen et al. 2014, Chanthy et al. 2012).
The glucosinolate content of canola (Brassica napus)
affects the taste and quality of the canola oil product.
Australian plant breeders actively select canola and
mustard (Brassica juncea) plants with the aim of
reducing the glucosinolate content as much as
possible. Mustards, despite higher glucosinolate
levels than canola, germinate faster and are more
tolerant to moisture stress (drought), traits which are
desirable for growing in dryer regions (Holland
2002). Plant breeders are now producing near-canola
mustard plants with glucosinolate levels comparable
to that found in canola (Burton et al. 2003), thereby
enabling canola quality mustards (canola-mustard) to
be grown in dryer regions, such as northern New
South Wales.
Glucosinolates play an important role in the host
plant-insect (pest) relationship. Glucosinolates, in
combination with flavonoids and isothiocyanates
(mustard oils) are responsible for attracting and
stimulating the feeding and oviposition of pest
species, e.g. diamondback moth (Plutella xylostella),
cabbage butterfly (Pieris spp.), Helicoverpa spp.,
cabbage aphids (Brevicoryne brassicae), and turnip
aphids (Lipaphis erysimi). Conversely, glucosinolate
is toxic to many insect species and thus responsible
for deterring and repelling many potential pests
(Hopkins et al. 2009). Few studies report on aphid
population dynamics on canolamustard, mustard and
conventional canola B. napus in the dryer regions of
northern NSW, where cabbage aphids are an
important pest of Brassica crops.
The main objectives of this study were to assess
attractiveness of three varieties of canola: (1) canola
(Pioneer® hybrid 45Y77) (Brassica napus), (2)
Juncea canola ‘Oasis’ (B. juncea) and (3) Canola-
mustard ‘Kaye’ (B. juncea) to aphids, and
performance of aphids on each variety. The results of
this study may provide useful guidelines for decision
making in canola crop management in northern New
South Wales. The physiological differences between
GEN. APPL. ENT. VOL 43, 2015
2!
canola and canola-mustards may result in differences
the pest aphid densities and nutrition.
MATERIALS AND METHODS
The study was conducted in the Zoology glasshouse
complex, University of New England, Armidale,
Australia, from January to June, 2012.
Cultivation of canola varieties
The seeds of three canola varieties (Table 1), (1)
canola (Pioneer® hybrid 45Y77) (B. napus), (2)
juncea canola ‘Oasis’ (B. juncea) and (3) canola-
mustard ‘Kaye’ (B. juncea), were obtained from New
South Wales Department of Primary Industries,
Tamworth. Twenty seeds of each canola variety were
sown in a germination tray (25 x 35cm) filled with
potting compost on 10th February 2012. Three-week-
old seedlings were transplanted individually to
conically shaped plastic pots (15cm diameter) filled
with the same potting compost. One plant was grown
in each plastic pot. Plants were kept in a glasshouse
compartment at 18-25°C and relative humidity (RH)
of 60-75%. All plants were watered daily without
adding fertilizers or chemical controls.
Table 1. Canola varieties tested in aphid feeding experiments and their morphological characteristics.
Canola variety
Morphological characteristics
Canola
Waxy green foliage, short and harder stem
Juncea canola
Dark green foliage, long and soft stem, early-flowering
Canola-mustard
Dark green foliage, young leaf surface has high trichome density, long and soft
stem, early-flowering
Aphid colony
To establish a laboratory culture, free-living cabbage
aphids B. brassicae were collected from broccoli
plants in Armidale, New South Wales and were then
maintained on new broccoli plants. Aphid stock
cultures were maintained in cages (1m x 0.7m x
0.7m) in a glasshouse (18-25°C, 60-75% RH) to
produce a suitable population of aphids for
experimental design. After two or three generations,
two-day-old females were used for the experiments
under glasshouse conditions.
Aphid performance on canola varieties
Experiment 1 Assessing population growth of
cabbage aphids on canola varieties
Ten plants from each canola variety were kept in the
glasshouse under the conditions of 18-25°C, 60-75%
RH and natural light. We measured cabbage aphid
performance on five-week old plants of each of the
three-canola varieties. Six plants at the same growth
stage of each variety were selected for the
experiment. Ten two-day-old wingless mature
females from the stock cabbage aphid colony were
placed on each plant using a paintbrush. Three plants
of each canola variety were then placed in a cage (1m
x 0.7m x 0.7m) with two cages per canola variety.
Aphid numbers (nymphs + wingless adults + winged
adults) on plants of each canola variety were counted
on days 3, 15 and 21 from the start of aphid
infestation. At higher aphid densities when direct
counting became difficult, the aphid population was
estimated by carefully counting (without disturbing)
the number of aphids on a measured part of the plant
and then the estimated population was extrapolated
for the whole plant. Aphid numbers were counted
separately on the leaves, the flowers and on the rest of
the plant. Total numbers of cabbage aphids on the
whole plant were also calculated based on aphids
counted on the separate plant parts. After three weeks
the number of wingless and winged aphids on each
canola variety was counted and recorded separately.
Relative susceptibilities of the different canola
varieties to aphid infestation were assessed by
comparing average abundance of aphids on the plants.
To assess the performance of cabbage aphids on the
different plant structures of each canola variety, aphid
numbers on the top leaves (two leaves per plant),
central stem, and inflorescence of each plant were
counted and recorded on the last observation day of
the experiment (21 days). All flowers were removed
from the plants and placed on white paper to count
the number of cabbage aphids directly.
GIA AND ANDREW: CABBAGE APHID ON CANOLA VARIETIES
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Experiment 2 - The reproductive performance of
cabbage aphids reared on different canola varieties
The reproductive performance of cabbage aphids was
studied on three canola varieties: canola, juncea
canola and canola-mustard in a glasshouse at 18-
250C, 60-75% RH and natural light using clip cages
(Fig. 1) (3cm diameter and 1.5cm depth fitted with
mesh lids) established on leaves of each plant at the
4-6 true leaf stage. To establish a cohort of first instar
nymphs (<24h old), viviparous wingless aphid adults
were transferred individually to the underside of a
predetermined mature leaf (below the top) of the plant
for each canola variety. Wingless aphids were placed
individually on each canola leaf and then confined in
a clip cage. After 16-18h (overnight), one first instar
nymph was left in each clip cage, while the wingless
adult aphid and other newborns were removed.
Fifteen replicate clip cages were established for each
canola variety (2-3 clip cages per plant) (Figure 1).
Daily observations were conducted to measure:
survival rates of the nymph until adult emergence;
and development period of immature stage of
cabbage aphids.
To measure fecundity on canola varieties, a
viviparous aphid (< 2 days old) was reared from the
immature stage and transferred to a new canola leaf
of the same variety, and then confined with a clip
cage as described previously. The cages were
observed daily to record numbers of offspring laid on
the leaf inside the clip cage. Nymphs were removed
from the cages after counting. If the aphid mother
died within the first 24h, it was replaced with a newly
emerged adult. Daily observations were recorded
until wingless adults died (up to 28 days).
Figure. 1. Canola plant specimen with clip cages
Data analysis
The data were analysed using Datadesk 6.3.1 and R
statistical software (version 2.14.1). In experiment 1,
cabbage aphid abundance (log x+1 transformed)
among canola varieties and plant parts were analysed
using a 2-way analysis of variance (ANOVA). In
experiment 2, effects of different canola varieties on
survival rate of the pre-reproductive stage of the
cabbage aphid were analysed using generalized linear
model (GLM). Fecundity and life table parameters of
cabbage aphids reared on three canola varieties were
also analysed using a one-way ANOVA. The
differences between means for ANOVA were
compared with least significant difference tests (α =
0.05).
The following equations were used to measure net
reproductive rate (R0) and mean generation time (T)
(Birch 1948; Laughlin 1965): Reproductive rate: R0 =
lxmx; Generation time: T = lxmxx/R0; intrinsic rate
of increase rm = ln(R0)/T; finite rate of increase λ =
erm; population doubling time DT = ln(2)/R0, where x
is the age of the immature and mature stages in days,
lx is survival of the immature and mature stages until
x, and mx is the number of born progeny at age x.
RESULTS
The population growth of the cabbage aphid
Brevicoryne brassicae on canola varieties
Total aphid number/canola plant: The population
growth of cabbage aphids reared on different varieties
of canola in all three observations is shown in Figure
2. Mean number of cabbage aphids did not differ
significantly among canola varieties, but did increase
significantly over time (Figure 2, Table 2). There was
no interaction between canola variety and time (Table
2).
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Figure 2. Boxplot showing population growth of the cabbage aphid under glasshouse conditions among three
canola varieties (canola, canola mustard, and juncea canola). Initial population size (Day 0 = 10). The
boundary of the box closest to zero indicates the 25th percentile, a line within the box marks the median,
dotted line marks the mean, and the boundary of the box farthest from zero indicates the 75th percentile.
Error bars above and below the box indicate the 90th and 10th percentiles.
Table 2. ANOVA output assessing population growth of the cabbage aphid on three canola varieties (Canola)
and at three times (Day). Significant values in bold.
df
SS
MS
F
p
2
0.12
0.06
2.45
0.098
2
130.84
65.42
2770.30
<0.0001
4
0.16
0.04
1.65
0.1783
45
1.06
0.02
53
132.18
Wingless and winged cabbage aphids on canola
varieties: There was no significant difference in the
number of alate and wingless adult aphids feeding on
the whole plant of three canola varieties. However,
there were significantly more wingless individuals
(Figure 3, Table 3) and an interaction with a
significant difference between alate individuals on
canola compared to canola-mustard (p=0.0426).
GIA AND ANDREW: CABBAGE APHID ON CANOLA VARIETIES
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Table 3. ANOVA for significant effect of canola varieties (Canola) on a number of alate and wingless adult
cabbage aphids (Winged). Significant values in bold.
Factor
df
SS
MS
F
p
Canola
2
0.18
0.09
0.88
0.4266
Winged
1
38.94
38.94
382.61
<0.0001
Canola*Winged
2
0.72
0.36
3.51
0.0426
Error
30
3.05
0.10
Total
35
42.88
Figure. 3. Mean number of alate and wingless adult cabbage aphids on three canola varieties (canola, canola
mustard , and juncea canola). The boundary of the box closest to zero indicates the 25th percentile, a line
within the box marks the median, dotted line marks the mean, and the boundary of the box farthest from zero
indicates the 75th percentile. Error bars above and below the box indicate the 90th and 10th percentiles.
!
Cabbage aphid reproductive performance on top
leaves, stems and flowers of canola plants: Aphid
abundance was significantly different between canola
varieties, plant structures, and their interaction
(Figure 4, Table 4). Aphids were significantly in
higher abundance on the top leaves of canola
compared to the stems of the same host plant, and
non-existent on the flowers. Abundance was also high
for canola when compared to canola-mustard and
juncea canola. Aphids on the stems of canola were
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significantly less abundant than on the stems of other
varieties. On canola-mustard, aphids were
significantly more abundant on the flowers compared
to stems and top leaves of the same species.
Table 4. ANOVA for significant effect of canola varieties (Canola) on abundance of cabbage aphids on
different structures of host plants (Structure). Significant values in bold.
Factor
df
SS
MS
F
p
Canola
2
52.06
26.03
173.84
<0.0001
Structure
2
23.83
11.91
79.56
<0.0001
Canola* Structure
4
100.52
25.13
167.84
<0.0001
Error
45
6.74
0.15
Total
53
183.14
Figure 4. Numbers of cabbage aphids on different plant structures (top leaves, strems, flowers) of canola
varieties (canola, canola mustard, and juncea canola). The boundary of the box closest to zero indicates the
25th percentile, a line within the box marks the median, dotted line marks the mean, and the boundary of the
box farthest from zero indicates the 75th percentile. Error bars above and below the box indicate the 90th and
10th percentiles.
GIA AND ANDREW: CABBAGE APHID ON CANOLA VARIETIES
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Effects of canola varieties on cabbage aphid
Brevicoryne brassicae survival and reproductive
performance
Survival rate of immature stage: Survival rate (%) of
the cabbage aphid (from birth to adult emergence) in
clip cages on tested canola varieties is shown in Table
5. Canola variety had no significant impact on
survival rate (%) of nymphal stage from birth to adult
emergence (p=0.098). Immature stages of cabbage
aphids passed through four nymphal instars to reach
the adult stage. All of the 1st instar nymphs survived.
Development, longevity and fecundity: There were no
significant differences in immature development
periods and longevity of cabbage aphid winged adults
reared on different canola varieties (F(2,42)=2.63,
p=0.085). The aphid nymphs passed through four
instars to reach maturity, with total time ranging from
7.78 days on canola-mustard to 8.58 days on canola.
Fecundity of the cabbage aphid was affected by
canola varieties with 55.93±3.35 nymphs/wingless
female on canola-mustard, 46.83±5.53 nymphs on
canola and 42.60±3.39 nymphs on juncea canola
(F(2,42)=3.52, p=0.04) (Table 6).
Life-history parameters: The intrinsic rate of increase
(rm) (F(2,42)=3.39, p=0.044), population growth rate
per day (λ) (F(2,42)=3.29, p=0.048) and doubling time
(days) (F(2,42)=3.78, p=0.032) were significantly
higher on canola-mustard compared to canola and
juncea canola (Table 7). However, mean generation
time (T) of the cabbage aphid in clip cages among
canola varieties was not significantly different under
glasshouse conditions (F(2,42)=1.94, p=0.158).
Table 5. Survival of immature stage of the cabbage aphid in clip cages on three canola varieties under
glasshouse conditions (n = 15)
% survival in nymphal instars
Canola varieties
1st
2nd
3rd
4th
PRD*
Canola
100
93.33
80
80
80
Canola-mustard
100
93.33
93.33
93.33
93.33
Juncea canola
100
100
100
100
100
(*) PRD: Adults during pre-reproductive delay
Table 6. Reproductive period, adult longevity (days ± SE) and fecundity (nymphs per wingless adult) of the
cabbage aphid in clip cages on three canola varieties. No significant difference in means (p >0.05) among stage
among varieites within stages indlicated with the same letter.
Canola variety
Host plant
Stage
Canola
Canola-mustard
Juncea Canola
Immature period (days)
8.58 ± 0.26a
7.78 ± 0.19a
8.06 ± 0.26a
Longevity of wingless aphid
12.83 ± 0.44a
12.07± 0.61a
13.60 ± 0.63a
Numbers of nymphs/female
46.83 ± 5.53b
55.93 ± 3.35a
42.60 ± 3.39b
Table 7. Population growth parameters of the cabbage aphid in clip cages on three canola varieties (mean ±
SE). No significant difference in means (p >0.05) among stage among varieites within stages indlicated with
the same letter.
Canola variety
Host plant
Parameters
Canola
Canola-mustard
Juncea Canola
Intrinsic rate of increase (rm)
0.316 ± 0.015b
0.364 ± 0.013a
0.325 ± 0.013b
Mean generation time T (days)
12.16 ± 0.38a
11.14 ± 0.39a
11.53 ± 0.31a
Finite rate of increase λ (day-1)
1.374 ± 0.021b
1.441 ± 0.018a
1.386 ± 0.019b
Doubling time DT (days)
2.241 ± 0.1a
1.934 ± 0.068b
2.176 ± 0.080a
DISCUSSION
This study demonstrates that three tested canola
varieties, namely canola (B. napus), canola-mustard
Kaye and juncea canola are very susceptible to
cabbage aphid infestation under glasshouse
conditions. In experiment 1, there were no significant
effects of canola variety on the population growth of
cabbage aphids at each assessment day. The cabbage
GEN. APPL. ENT. VOL 43, 2015
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aphid performance, however, indicates different
responses to plant parts within a canola species.
Cabbage aphids performed well (based on abundance)
on the topmost young leaves of canola, whereas on
canola-mustard and juncea canola more aphids were
found on stems, leaves and flowers. Holland et al.
(2003), reported that mustard has a higher content of
glucosinolates than canola and juncea canola.
Moreover, glucosinolates occur differently across
parts of the plant and their total concentration
decreases as the leaf tissue matures (Lambdon et al.
2003), and variation of glucosinolates also occurs on
small spatial scales within leaves (Shelton 2005). On
yellow mustard (Sinapis alba), cabbage aphids prefer
young parts of the growing stems, possibly to
compensate for the presence of glucosinolates
elsewhere on the plant (Hopkins et al. 1998).
Previous studies investigating the distribution of
glucosinolates show considerable variation among
plant organs and even plant development stages. The
highest glucosinolate levels are found in youngest
leaves (Lambdon and Hassall 2005), and in
reproductive tissues of flowers and seeds (Brown et
al. 2003; Smallegange et al. 2007).
In a previous study, Cole (1997a), found that the
population growth rate of cabbage aphids reared on a
wide range of wild and cultivated Brassica varieties
has a strong relationship with a combination of four
glucosinolates (sinigrin, gluconapin, progoitrin and
napoleiferin). Additionally, the physical structures of
host plants could affect the oviposition preference of
aphids (Fathi et al. 2011). The information on
morphological features of canola varieties indicates
that canola-mustard and juncea canola are early-
flowering and more attractive to cabbage aphid
feeding. The harder stem of canola however, could
limit feeding behaviour of cabbage aphids (Table 4).
In this study, our results showed that numbers of
wingless adult cabbage aphids at the last observation
(21 days) were not different among canola varieties,
but marginally higher number of alates occurred on
canola. Other studies have pointed out that nutritional
quality of aphid diets has a correlation with the
production of winged morphs (Mittler and Kleinjan
1970; Vereschagina and Shaposhnikov 1998). A
review by Müller et al. (2001), showed that poor
nutritional quality of host plants is not always related
to increased production of winged morphs in aphids.
The production of winged aphid adults may be
affected by different factors such as environmental
cues, density, unfavourable abiotic conditions,
interactions among aphid species, or even maternal
effects. Here, our results suggest that crowding within
cabbage aphid populations on the canola varieties is
likely to induce the production of winged aphids.
In experiment 2, the canola varieties tested had no
significant effects on the survival rate and duration of
immature development of the cabbage aphids in clip
cages. The nymphs developed through four nymphal
instars ranging from 7.78 days to 8.58 days with a
high survival rate (80-100%). Similar trends were
observed in the longevity of wingless adults and mean
generation time (from birth to first oviposition), both
of which did not vary among canola varieties. The
presence of trichomes on mustard leaf surfaces had
non-significant effects on the reproductive
performance of the cabbage aphids in clip cages.
However, experiment 2 showed that fecundity and the
population growth parameters such as rm, λ and
doubling time (DT) of the cabbage aphid are affected
by canola varieties when cabbage aphids were kept in
clip cages on mature leaves. Fecundity of the cabbage
aphid was lowest when females were reared
individually on leaves of juncea canola and highest
when reared on canola-mustard. Compared with the
study of Mirmohammadi et al. (2009), undertaken on
oilseed rape varieties, fecundity and rm in this
experiment are higher and show significant difference
between the tested varieties. However, Ulusoy and
Ölmez-Bayhan (2006), showed that mustard was
resistant to cabbage aphids based on the low values of
rm and fecundity which were measured on excised
leaves under laboratory conditions. Indeed, different
environmental conditions or rearing techniques could
lead to different life-history parameters of aphid
individuals. Cole (1997b), suggested that various
concentrations of glucosinolates in some Brassica
varieties could cause changes in the values of rm.
Moreover, in experiment 2, the use of clip cages
without knowledge of aphid performance on various
parts of the plants might be giving an over or
underestimate of rm.
Mustard and canola appear to be suitably adapted to
parts of Australia with dry and warm conditions.
These crop species may have an important role due to
their superior drought resistance characteristics, and
consequently higher yields in the harsh climates
(Spenceley et al. 2003). Environmental stresses such
as drought and changing temperature can have
profound effects on the biochemical composition of
host plants and subsequently affect aphid
communities. These stressors may be amplified with
the predicted warming and drying climate over the
coming decades (CSIRO-ABM 2012). Such changes
may alter the ecology, physiology and behaviour of
aphids (Andrew et al. 2013b), with some
GIA AND ANDREW: CABBAGE APHID ON CANOLA VARIETIES
9!
unpredictable effects. This may then lead to further
plant stress via reducing plant nitrogen uptake from
the soil (Katayama et al. 2014) and proliferation of
aphid-borne viruses (Finlay and Luck 2011). In this
study under glasshouse conditions, no significant
differences were found between tested canola
varieties and aphid abundance. Further research to
assess the ability of mustard and canola varieties to
resist aphid infestation in the drier and warmer
regions of Australia would be beneficial.
In conclusion, three canola varieties: canola, juncea
canola and canola-mustard were very susceptible to
cabbage aphids. Total aphid numbers did not vary
significantly among tested canola species over the
assessment period under glasshouse conditions.
Cabbage aphids responded differently to different
parts of the plant on different varieties. A higher
population of the cabbage aphids was observed on the
topmost leaves of canola. However, on canola-
mustard aphids were significantly more abundant on
the flowers compared to stems and top leaves of the
same species. Unlike free-living aphids on plants,
analysis of variance showed that the canola varieties
affected some life-history parameters of cabbage
aphid individuals confined in clip cages on mature
leaves. No significant differences were found in the
nymphal development period, survival longevity and
mean generation time of cabbage aphids among
canola varieties. Further research is required to
investigate the performance of other aphid species
and insect pests attacking new canola varieties in
northern NSW. Studying aphid responses to
environmental stress-induced changes in conventional
and new canola varieties is also needed and may have
scientific significance in canola breeding programs.
ACKNOWLEDGEMENTS
We would like to thank Adrian Nicholas of NSW
Department of Primary Industries, Tamworth, NSW,
Australia, for supplying aphids and canola seeds.
Graham Hall, Michelle Yates, Bianca Bishop and
Sarah Hill (Insect Ecology Lab, UNE) who kindly
commented on an earlier drafts of the manuscript.
This research was partially funded by Agricultural
Science and Technology Scholarship, Vietnam.
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... Biotic environments are influenced by nearby organisms, such as common herbivores insect, which are mostly influenced by change in leaves surface's temperature and humidity by opening of stomata Zahoor et al. 2019). Both abiotic and biotic environments can be influenced to some extent by organisms to find their most favorable climate and make it difficult to predict the change in climate (Gia and Andrew 2015;Akram et al. 2018a, b). ...
Chapter
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Insect responses to climate change are vital for knowing the response of agroecosystems to climate change. Although numerous insect species are pests in crops, yet they also play critical roles as parasitoids and predators for other key pest species. Changes in an insect population’s biochemistry, physiology, population dynamics, and biogeography may occur due to alterations in their distribution, among crop types and among the growing seasons . The response of an insect population to a quickly changing climate may also be inconsistent when insects have to interact with diverse competitors, parasitoids, and predators, and impose variable costs at a no. of life stages. The overall influence is on food production systems which can be already at acute risk from the influences of climate change. A significant limitation in improving crop production is the massive yield loss due to diseases, insect pests, and weeds all around the world. An unwise application of pesticides on crops has produced resistance among the insects and other pests and caused a severe effect on the economy of any country. This condition demands the need to endorse the idea of integrated pest management (IPM) among the farmers. IPM techniques are highly environment-sensitive that depend on the reasonable blend of physical, social, and biochemical control strategies utilized to control the pests, to minimize the economic loss and hazardous impact on the environment.
... Biotic environments are influenced by nearby organisms, such as common herbivores insect, which are mostly influenced by change in leaves surface's temperature and humidity by opening of stomata . Both abiotic and biotic environments can be influenced to some extent by organisms to find their most favorable climate and make it difficult to predict the change in climate (Gia and Andrew 2015;Akram et al. 2018a, b). ...
Chapter
Agricultural production is low in many parts of the world which is subjected to limited adaptability toward adverse events. Climate change (CC) is estimated to decrease productivity on even lower levels and has made production more inconsistent. Many countries all over the world have planned to accept climate smart agriculture (CSA) approach to make improvements in agriculture. The CSA refers to a combined set of technologies and practices that simultaneously improve farm productivity as well as monetary return, enhance adaptability to CC, and minimize the emissions of greenhouse gas (GHG). The concept of CSA is gaining significance at national and international levels to cope with future challenges of the agricultural-related plannings. The CSA is a notion that calls for the combination of the need of adaptability to CC and strategies for mitigation in agriculture to ensure food security. For instance, strategies like the use of renewable energy for agriculture, i.e., pyrolysis units, solar panels, windmills, as well as water pumps are very vital for food production. The concept of CSA comprehends three major stakes (productivity, adaptation, and mitigation), but the literature has not fully addressed them in an integrated way. Adaptation and productivity were of prime importance for poor and under developing countries, while mitigation was mainly addressed in developed countries. The utmost challenge for policymakers and stakeholders to operationalize CSA is the identification, assessment (cost-benefit ratio), as well as subsequent ordering of CSA options and portfolios for investment. The aims of CSA are to sustainably increase farmer’s resilience, improve agricultural productivity, achieve food security and sustainable development goals in addition to reduce emissions of GHG.
... It takes 16-50 days to complete one life cycle which is dependent on temperature, being shorter at higher temperatures (Kessing and Mau 1991). Gia and Andrew (2015) reported that B. brassicae nymphs developed through four nymphal instars ranging from 7.8 to 8.6 days with a high survival rate (80-100%) on different canola varieties. B. brassicae remains active on cabbage crop from last week of January (26.2 aphids/plant) to last week of April (18.4 aphids/plant) in Solan, Himachal Pradesh Verma et al. (2017). ...
Chapter
Full-text available
The rapeseed-mustard crop basket is highly vulnerable to an umbrella of insectpests at different phases of plant growth, known to cause 15–30% loss in yield in different oilseed crops in India and different parts of the world. In India, rapeseedmustard, the major Rabi oilseed crops are known to be ravaged by about more than three dozen species of insect-pests. The insect-pests feeding on these crops can be broadly classified as chewing (Coleoptera, Lepidoptera, Hymenoptera), piercing and/or sucking (Heteroptera, Homoptera, Thysanoptera) and putrefying (Diptera). Out of which, the sucking insect-pests, namely mustard aphid, Lipaphis erysimi (Kaltenbach), cabbage aphid, Brevicoryne brassicae (Linn.), green peach aphid, Myzus persicae (Sulzer) and painted bug, Bagrada hilaris (Burmeister) have been consistent and serious bottlenecks in the production of these oleiferous crops in Indian sub-continent. In this chapter, the major sucking pests of rapeseed-mustard have been covered with relevance on their global distribution, identification, life cycle, nature of damage, extent of losses and integrated pest management.
... It takes 16-50 days to complete one life cycle which is dependent on temperature, being shorter at higher temperatures (Kessing and Mau 1991). Gia and Andrew (2015) reported that B. brassicae nymphs developed through four nymphal instars ranging from 7.8 to 8.6 days with a high survival rate (80-100%) on different canola varieties. B. brassicae remains active on cabbage crop from last week of January (26.2 aphids/plant) to last week of April (18.4 aphids/plant) in Solan, Himachal Pradesh Verma et al. (2017). ...
Chapter
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... It takes 16-50 days to complete one life cycle which is dependent on temperature, being shorter at higher temperatures (Kessing and Mau 1991). Gia and Andrew (2015) reported that B. brassicae nymphs developed through four nymphal instars ranging from 7.8 to 8.6 days with a high survival rate (80-100%) on different canola varieties. B. brassicae remains active on cabbage crop from last week of January (26.2 aphids/plant) to last week of April (18.4 aphids/plant) in Solan, Himachal Pradesh Verma et al. (2017). ...
Chapter
Full-text available
Major sucking insect and mite pests of citrus in India are: citrus psylla, Diaphorina citri Kuwayama; citrus whitefly, Dialeurodes citri (Ashmead) and Aleurocanthus marlatti (Quaintance); citrus blackfly, Aleurocanthus woglumi Ashby; aphids, Black citrus aphid, Toxoptera aurantii (Boyer de Fonscolombe); Green peach aphid, Myzus persicae (Sulzer); Cotton aphid, Aphis gossypii Glover; Aphis craccivora Koch; Aphis spiraecola (Patch); Brown aphid, Toxoptera citricida Kirkaldy; citrus thrips, Scirtothrips citri (Moulton); Scirothrips dorsalis Hood; Scirtothrips oligochaetus (Karny), Thrips hawaiiensis (Morgan) and Aeolothrips sp.; Thrips nilgiriensis (Ananthakrishnan); fruit sucking moths, Eudocima fullonia (Clerck), E. materna (Linnaeus), Acanthodelta (=Achaea) janata (Linnaeus) and E. homaena Hubner (=O. ancilla Formosana; mealybugs, Planococcus citri (Risso), P. lilacinus Cockerell, Nipaecoccus viridis Newstead, Maconellicoccus hirsutus Green, Drosicha mangiferae Green, D. stebbingi (Green) and Nipaecoccus (Pseudococcus) filamentosus (Cockerell). Mite species damaging citrus are Citrus mite, Eutetranychus orientalis Klein, False spider mite, Brevipalpus sp.; Polyphagotarsonemus latus (Banks); Citrus rust mite, Phyllocoptruta oleivora (Ashmead); Brevipalpus rogulosus (Chaudhri, Akbar & Rasool); Green mite, Schizotetranychus hindustanicus Hirst. Minor sucking insect pests of citrus in India are: Citrus scales, California red scale, Aonidiella aurantii (Maskell), cottony cushion scale, Icerya aegyptiaca (Douglas), Aspidiotus destructor Signoret, Aulacaspis tubercularis Newstead, Ceroplastes sp. and soft scale, Coccus sp.; and Snow scale, Unaspis citri (Comstock).
... It takes 16-50 days to complete one life cycle which is dependent on temperature, being shorter at higher temperatures (Kessing and Mau 1991). Gia and Andrew (2015) reported that B. brassicae nymphs developed through four nymphal instars ranging from 7.8 to 8.6 days with a high survival rate (80-100%) on different canola varieties. B. brassicae remains active on cabbage crop from last week of January (26.2 aphids/plant) to last week of April (18.4 aphids/plant) in Solan, Himachal Pradesh Verma et al. (2017). ...
Chapter
Many of the world’s best-known and favourite fruits (such as apple, pear, peach, plum, grape, and strawberry) are adapted to climates in the middle latitudes and are known as temperate fruits. These fruits require some cold periods (dormancy) to complete their life cycle and have various degrees of winter hardiness, which conditions their adaptability in cold climates. Among various crops, apple, walnut, and pear represent major crops of temperate fruits covering about 54, 22, and 6.9% of the total area and accounting for 82.3, 1.1, and 5.6% of temperate fruit production, respectively, while rest of the production comes from other fruits like peach, plum, almond, apricot, cherries, etc. Attack by insect pests remains a major limiting factor on the production of these fruits and can range from 10 to 35%. Sucking pests especially are major causes of yield loss. In this chapter, the detail scientific information regarding the sucking insect pests including ecology, life cycle, nature of damage, and management strategies are discussed.
... However, in our study, we used the Marcanta cultivar. Indeed, the literature has demonstrated the effect of cabbage cultivar in B. brassicae fecundity (Ellis & Farrell, 1995;Gia & Andrew, 2015;Maremela, Tiroesele, Obopile, & Tshegofatso, 2013). ...
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The cabbage aphid, Brevicoryne brassicae, is a pest of many plants of the Brassicaceae family including cabbage, Brassica oleracea Linnaeus, 1753. We investigated the effect of temperature on the biological parameters of B. brassicae using different temperature based models incorporated in the Insect Life Cycle Modelling (ILCYM) software. Nymphs of first stage were individually placed in the incubators successively set at 10°C, 15°C, 20°C, 25°C, 30°C, and 35°C; 75 ± 5% RH; and L12: D12-hr photoperiods. We found that first nymph reached the adult stage after 18.45 ± 0.04 days (10°C), 10.37 ± 0.26 days (15°C), 6.42 ± 0.07 days (20°C), 5.076 ± 0.09 days (25°C), and 5.05 ± 0.10 days (30°C), and failed at 35°C. The lower lethal temperatures for B. brassicae were 1.64°C, 1.57°C, 1.56°C, and 1.62°C with a thermal constant for development of 0.88, 0.87, and 0.08, 0.79 degree/day for nymphs I, II, III, and IV, respectively. The temperatures 10, 30, and 35°C were more lethal than 15, 20, and 25°C. Longevity was highest at 10°C (35.07 ± 1.38 days). Fertility was nil at 30°C and highest at 20°C (46.36 ± 1.73 nymphs/female). The sto-chastic simulation of the models obtained from the precedent biological parameters revealed that the life table parameters of B. brassicae were affected by the temperature. The net reproduction rate was highest at 20°C and lowest at 30°C. The average generation time decreased from 36.85 ± 1.5 days (15°C) to 6.86 ± 0.1 days (30°C); the intrinsic rate of increase and the finite rate of increase were highest at 25°C. In general, the life cycle data and mathematical functions obtained in this study clearly illustrate the effect of temperature on the biology of B. brassicae. This knowledge will contribute to predicting the changes that may occur in a population of B. Brassiace in response to temperature variation. K E Y W O R D S Brevicoryne brassicae, life table, phenological models, temperature
... However, in our study, we used the Marcanta cultivar. Indeed, the literature has demonstrated the effect of cabbage cultivar in B. brassicae fecundity (Ellis & Farrell, 1995;Gia & Andrew, 2015;Maremela, Tiroesele, Obopile, & Tshegofatso, 2013). ...
... However, in our study, we used the Marcanta cultivar. Indeed, the literature has demonstrated the effect of cabbage cultivar in B. brassicae fecundity (Ellis & Farrell, 1995;Gia & Andrew, 2015;Maremela, Tiroesele, Obopile, & Tshegofatso, 2013). ...
Article
Full-text available
The cabbage aphid, Brevicoryne brassicae, is a pest of many plants of the Brassicaceae family including cabbage, Brassica oleracea Linnaeus, 1753. We investigated the effect of temperature on the biological parameters of B. brassicae using different temperature‐based models incorporated in the Insect Life Cycle Modelling (ILCYM) software. Nymphs of first stage were individually placed in the incubators successively set at 10°C, 15°C, 20°C, 25°C, 30°C, and 35°C; 75 ± 5% RH; and L12: D12‐hr photoperiods. We found that first nymph reached the adult stage after 18.45 ± 0.04 days (10°C), 10.37 ± 0.26 days (15°C), 6.42 ± 0.07 days (20°C), 5.076 ± 0.09 days (25°C), and 5.05 ± 0.10 days (30°C), and failed at 35°C. The lower lethal temperatures for B. brassicae were 1.64°C, 1.57°C, 1.56°C, and 1.62°C with a thermal constant for development of 0.88, 0.87, and 0.08, 0.79 degree/day for nymphs I, II, III, and IV, respectively. The temperatures 10, 30, and 35°C were more lethal than 15, 20, and 25°C. Longevity was highest at 10°C (35.07 ± 1.38 days). Fertility was nil at 30°C and highest at 20°C (46.36 ± 1.73 nymphs/female). The stochastic simulation of the models obtained from the precedent biological parameters revealed that the life table parameters of B. brassicae were affected by the temperature. The net reproduction rate was highest at 20°C and lowest at 30°C. The average generation time decreased from 36.85 ± 1.5 days (15°C) to 6.86 ± 0.1 days (30°C); the intrinsic rate of increase and the finite rate of increase were highest at 25°C. In general, the life cycle data and mathematical functions obtained in this study clearly illustrate the effect of temperature on the biology of B. brassicae. This knowledge will contribute to predicting the changes that may occur in a population of B. Brassiace in response to temperature variation.
Chapter
The rapeseed-mustard crop basket is highly vulnerable to an umbrella of insect-pests at different phases of plant growth, known to cause 15–30% loss in yield in different oilseed crops in India and different parts of the world. In India, rapeseed-mustard, the major Rabi oilseed crops are known to be ravaged by about more than three dozen species of insect-pests. The insect-pests feeding on these crops can be broadly classified as chewing (Coleoptera, Lepidoptera, Hymenoptera), piercing and/or sucking (Heteroptera, Homoptera, Thysanoptera) and putrefying (Diptera). Out of which, the sucking insect-pests, namely mustard aphid, Lipaphis erysimi (Kaltenbach), cabbage aphid, Brevicoryne brassicae (Linn.), green peach aphid, Myzus persicae (Sulzer) and painted bug, Bagrada hilaris (Burmeister) have been consistent and serious bottlenecks in the production of these oleiferous crops in Indian sub-continent. In this chapter, the major sucking pests of rapeseed-mustard have been covered with relevance on their global distribution, identification, life cycle, nature of damage, extent of losses and integrated pest management.
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Climate change is recognized as one of the most serious scientific issues to understand and respond to (AAS, 2010). One of the most fundamental issues is to recognize how our biota will respond and adapt to such rapid changes at a global scale. Already global mean temperature has risen by 0.76°C this century (IPCC, 2007), and recent research indicates that current temperature increases are tracking the upper range projected by the IPCC modeled predictions and sea-level change is faster than projected (Rahmstorf et al., 2007; Steffen et al., 2009). Across Australia, different regions have experienced climatic changes to varying degrees, both seasonally and annually. Future predictions are for a generally warmer and drier continent by 2030 (CSIRO, 2007), but with the likely impacts of climate change being complex and highly variable across the continent, and worldwide (Walther et al., 2002). Changes in the physiological tolerances and population depletion could cause major population restructure of currently common species, leading to the collapse of trophic interactions and depletion of ecosystem services. Two of the great challenges in predicting how biological organisms will respond to a rapidly changing climate are (i) determining whether responses of organisms are idiosyncratic, or whether there are underlying generalities that can be made based on evolutionary relationships, or ecological associations, and (ii) determining whether these responses are consistent in time and space (Andrew & Terblanche, in press).
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We outline research progress on canola and mustard agronomy and variety selection for northern NSW and southern Qld. We discuss variety performance, relative performance of Indian mustard over canola in dry environments, the prospects for producing high quality canola reliably in the region, and phosphorous nutrition. We end with a statement of future research priorities for the crop in the northern wheat-belt.
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The search for profitable alternatives to cereals in the low rainfall cropping environments has been a high priority in Australian agriculture in recent years. No oilseed crop is well adapted to the 225–350 mm rainfall environments, which occupy over three million hectares of arable land across Australia. Development of a suitable oilseed crop for this region would provide a rotational break to control root diseases and weeds that are difficult to manage in a cereal/pasture rotation. The near canola quality B. juncea Australian lines have showed good yield potential in comparison to currently grown early and early-mid maturing B. napus cultivars AG-Outback and Rainbow. Compared to B. napus, the superior yield, shattering tolerance, better early vigour and disease resistance characteristics of B. juncea will encourage growers to use this species in crop rotations where currently oilseeds are not grown once released in two to three years. Future challenges include the further development of high yielding and high oil cultivars and fully exploiting the existing variability and incorporation of herbicide tolerance and other disease resistant traits.
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The cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae), is a key pest of oilseed rape, Brassica napus L., and produces economic damage. Commonly, life table parameters have been used to compare insect Þtness on different varieties. Effects of four different varieties of oilseed rape (ÔZarfamÕ, ÔLicordÕ, ÔHyola 401Õ, and ÔSLM046Õ) on biological aspects and fecundity life table parameters of B. brassicae were studied under laboratory conditions. There was no signiÞcant difference between the length of prereproductive, reproductive, postreproductive periods, and fecundity of aphid developing on different varieties. The maximum length of prereproductive, reproductive, and longevity periods of B. brassicae were observed in the Licord variety. The maximum fecundity of aphid was recorded on Hyola 401. The intrinsic rate of increase was estimated by using EulerÐLotka equation and was compared with those estimated using Wyatt and WhiteÕs equation. Intrinsic rate of increase of B. brassicae (based on jackknife method) was 0.298, 0.294, 0.311, and 0.289 on Zarfam, Licord, Hyola 401, and SLM046, respectively. Feeding on SLM046 and Licord reduced the reproductive capacity of the cabbage aphid compared with the other varieties studied. However, statistical analysis of Wyatt and White output showed that calculated rm were higher than that EulerÐLotka equation and there was not signiÞcant difference between rmon different varieties. Aphid population growth 20 d after plant infestation showed no signiÞcant difference between numbers of produced aphids, but signiÞcant difference in the number of winged aphids.
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Thermal sensitivity is a crucial determinant of insect abundance and distribution. The way it is measured can have a critical influence on the conclusions made. Diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is an important insect pest of cruciferous crops around the world and the thermal responses of polyphagous species are critical to understand the influences of a rapidly changing climate on their distribution and abundance. Experiments were carried out to the lethal temperature limits (ULT0 and LLT0: temperatures where there is no survival) as well as Upper and Lower Lethal Temperature (ULT25 and LLT25) (temperature where 25% DBM survived) of lab-reared adult DBM population to extreme temperatures attained by either two-way ramping (ramping temperatures from baseline to LT25 and ramping back again) or sudden plunging method. In this study the ULT0 for DBM was recorded as 42.6°C and LLT0 was recorded as -16.5°C. DBM had an ULT25 of 41.8°C and LLT25 of -15.2°C. The duration of exposure to extreme temperatures had significant impacts on survival of DBM, with extreme temperatures and/or longer durations contributing to higher lethality. Comparing the two-way ramping temperature treatment to that of direct plunging temperature treatment, our study clearly demonstrated that DBM was more tolerant to temperature in the two-way ramping assay than that of the plunging assay for cold temperatures, but at warmer temperatures survival exhibited no differences between ramping and plunging. These results suggest that DBM will not be put under physiological stress from a rapidly changing climate, rather access to host plants in marginal habitats has enabled them to expand their distribution. Two-way temperature ramping enhances survival of DBM at cold temperatures, and this needs to be examined across a range of taxa and life stages to determine if enhanced survival is widespread incorporating a ramping recovery method.
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