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CHEMICAL AND PHYSICAL FACTORS INVOLVED IN THE AGGREGATION
BEHAVIOUR OF HARMONIA AXYRIDIS PALLAS
Department of Functional and Evolutionary Entomology
Durieux D., Fischer C., Deneubourg J.L., Brostaux Y., Lognay G. , Vandereycken A., Joie E., Haubruge E., Verheggen F. J.
CONTEXT
AGGREGATION
annoyance from their number
tainting walls and curtains
allergic reactions
asthma
urticariarhinitis
cough,…conjunctivitis
ISCE, Durieux D. et al.
CONTEXT
Migratory flight Macrosite choice
Microsite choice
Physical factors
Chemical factors
?
ISCE, Durieux D. et al.
CHEMICAL FACTORS : PREVIOUS STUDIES
Volatile compounds Pyrazines (al Abassi et al., 1998)
(-)- β-caryophylleneEmission by H. axyridis in wintering conditions(Brown et al., 2006)
the seven spotted ladybird, Coccinella septempuctata
Attractive and aggregative potential (Verheggen et al., 2007)
ISCE, Durieux D. et al.
CHEMICAL FACTORS
1
6
2 3
4 5
Multi-choice experiment
Implication of long chain hydrocarbons in the aggregation behavior of Harmonia axyridis (PALLAS) (Coleoptera: Coccinellidae) Durieux D., Fischer C., Deneubourg J.L., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (under review)
ISCE, Durieux D. et al.
CHEMICAL FACTORS
1
6
2 3
4 5
After 8 hours:
Test χ² (chi-square of goodness-of-fit test) : P < 0,001
Multi-choice experiment
Implication of long chain hydrocarbons in the aggregation behavior of Harmonia axyridis (PALLAS) (Coleoptera: Coccinellidae) Durieux D., Fischer C., Deneubourg J.L., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (under review)
0
10
20
30
40
50
60
1 2 3 4 5 6
mea
n pe
rcen
tage
of H
. axy
ridis
Area of the multi-choice set-up
***
ISCE, Durieux D. et al.
CHEMICAL FACTORS
1
6
2 3
4 5
Multi-choice experiment
Implication of long chain hydrocarbons in the aggregation behavior of Harmonia axyridis (PALLAS) (Coleoptera: Coccinellidae) Durieux D., Fischer C., Deneubourg J.L., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (under review)
ISCE, Durieux D. et al.
hexane
CHEMICAL FACTORS
1
6
2 3
4 5
After 8 hours:
Test χ² (chi-square of goodness-of-fit test) : P < 0,001
Multi-choice experiment
Implication of long chain hydrocarbons in the aggregation behavior of Harmonia axyridis (PALLAS) (Coleoptera: Coccinellidae) Durieux D., Fischer C., Deneubourg J.L., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (under review)
0
5
10
15
20
25
30
35
40
45
1 2 3 4 5 6M
ean
perc
enta
ge o
f H. a
xyrid
isArea of the multi-choice set-up
***
The chemical blend ensures the cohesion of the aggregate
ISCE, Durieux D. et al.
CHEMICAL FACTORS
9
Test χ² (chi-square of goodness-of-fit test) : P = 0.024 for females and P < 0.001 for males
Implication of long chain hydrocarbons in the aggregation behavior of Harmonia axyridis (PALLAS) (Coleoptera: Coccinellidae) Durieux D., Fischer C., Deneubourg J.L., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (under review)
Y-olfactometer
ISCE, Durieux D. et al.
0
10
20
30
40
50
60
70
80
90
100
males females
Perc
enta
ge o
f lad
ybird
s ha
ving
ch
osen
eac
h ar
m
*** *
Theoretical
distribution
Study of a potential trail
CHEMICAL FACTORS
10
Test χ² (chi-square of goodness-of-fit test) : P = 0.001 for females and P = 0.002 for males
Implication of long chain hydrocarbons in the aggregation behavior of Harmonia axyridis (PALLAS) (Coleoptera: Coccinellidae) Durieux D., Fischer C., Deneubourg J.L., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (under review)
0
10
20
30
40
50
60
70
80
90
100
males females
Perc
enta
ge o
f lad
ybird
s ha
ving
ch
osen
eac
h ar
m
** **
Theoretical
distribution
Y-olfactometer
The chemical blend leads congeners towards the aggregate
ISCE, Durieux D. et al.
Hexane
CHEMICAL FACTORS
11
Identification of compounds by GC-MS analyses
1 : heneicosane 10 : heptacosane2 : docosane 11 : nonacosadiène3 : tricosane 12 : nonacos-9-ène4 : tétracosane 13 : nonacosane5 : pentacos-9-ène 14 : hentriacontadiène6 : pentacosane 15: hentriacontadiène7 : hexacosane 16 : hentriacont-9-ène8 : heptacosadiène 17 : hentriacontane9 : heptacos-9-ène
Identified compounds
Saturated hydrocarbonsUnsaturated hydrocarbons – one double bondUnsaturated hydrocarbons – two double bonds
Aggregation blendTrail blend
Identification of the compounds used by the multicolored Asian ladybeetle in its hivernation process. Durieux D., Fischer C., Lognay G., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (in prep.)
ISCE, Durieux D. et al.
Macrosite’s choice Contrasting elements (Nalepa, 2005) Whitish and light-colored objects (Obata, 1986)
Microsite’s choice temperature photoperiod thigmotactism,…
12
PHYSICAL FACTORS : PREVIOUS STUDIES
ISCE, Durieux D. et al.
presence of congeners
luminosity of shelters
PHYSICAL FACTORS
13Aggregation behaviour of Harmonia axyridis adults in non-wintering conditions Durieux D., Deneubourg J.L., Brostaux Y., Vandereycken A., Joie E., Haubruge E. and Verheggen F.J. (in prep.)
shelter
arena 2 tested parameters:
- The luminosity of shelters- The presence of congeners
binary choice experiment
1 ladybird20 ladybirds50 ladybirds
ISCE, Durieux D. et al.
PHYSICAL FACTORS
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IMPACT OF CONGENERS
20 ladybirds 50 ladybirds10 min 0.028 * 0.10620 min 0.107 0.002 **30 min 0.007 ** < 0.001 ***40 min 0.108 < 0.001 ***50 min 0.012 * < 0.001 ***
1 h 0.080 < 0.001 ***3h < 0.001 *** < 0.001 ***5h < 0.001 *** < 0.001 ***8h < 0.001 *** < 0.001 ***
P valueobservation times
Generalized linear model comparing the observed distribution with a binomial one
ISCE, Durieux D. et al.
PHYSICAL FACTORS
15
IMPACT OF SHELTER’S LUMINOSITY
0.00
0.20
0.40
0.60
0.80
1.00
10 20 30 40 50 60 180 300 480
prop
ortio
n of
shel
tere
d la
dybi
rds
observation time (in minutes)
transparent shelters dark shelters
***
Binary logistic regression : luminosity : P < 0.001 *** time : P < 0.001 ***
ISCE, Durieux D. et al.
20 ladybirds tested
CONCLUSION
Hydrocarbons are involved in the aggregation To lead congeners towards aggregation sites To ensure the cohesion of the aggregate
There are social interactions between ladybirds even in non-wintering conditions
Ladybirds prefer dark shelters
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ISCE, Durieux D. et al.
THANK YOU FOR YOUR ATTENTION
PHYSICAL FACTORS
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IMPACT OF SHELTER’S LUMINOSITY
0.00
0.20
0.40
0.60
0.80
1.00
10 20 30 40 50 60 180 300 480
prop
ortio
n of
shel
tere
d la
dybi
rds
observation time (in minutes)
transparent shelters dark shelters
***
Binary logistic regression : luminosity : P < 0.001 *** time : P < 0.001 *** luminosity * time : P <
0.001 ***
PHYSICAL FACTORS
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IMPACT OF INDIVIDUALS’ DENSITY
00.10.20.30.40.50.60.70.80.9
1
0 120 240 360 480
mea
n pr
opor
tions
of s
helte
red
lady
bird
s
time (in minutes)
TS_1 ladybird
TS_20 ladybirds
TS_50 ladybirds
CS_1 ladybird
CS_20 ladybirds
CS_50 ladybirds
Transparent shelters (TS)Covered shelters (CS)