Science Facing Aliens - Invasive Alien Species in Belgium - Belgian ...
Science Facing Aliens - Invasive Alien Species in Belgium - Belgian ... Science Facing Aliens - Invasive Alien Species in Belgium - Belgian ...
32 Ladybirds sampled From the 20 sites sampled, 13 species of adult ladybirds were collected (Figure 1). The most abundant species was H. axyridis: it was present in 18 out of the 20 sites sampled and was also the most abundant with 791 specimens collected. Next, but 15 times less abundant and each present on half of the sites, were 4 natives species: 3 aphidophagous tree species, A. decempunctata (L.), Calvia quatuordecimguttata (L.) and Calvia decemguttata (L.), and 1 mycetophagous species: Halyzia sedecimguttata (L.). Further, 2 generalist species and 2 tree species were caught: A. bipunctata (L.), Propylea quatuordecimpunctata (L.) and Exochomus quadripustulatus (L.), Oenopia conglobata (L.), respectively. Anatis ocelata (L.), Myrrha octodecimguttata (L.) and Aphidecta obliterata (L.) live in coniferous trees and are not associated with lime trees, which explains the low catch of these species. Anatis ocelata (1/20) Myrrha 18-guttata (1/20) Psyllobora 22-punctata (1/20) Oenopia conglobata (1/20) Aphidecta obliterata (2/20) Propylea 14-punctata (2/20) Exochomus 4-pustulatus (2/20) Adalia 2-punctata (7/20) Halyzia 16-guttata (11/20) Calvia 10-guttata (11/20) Calvia 14-guttata (12/20) Adalia 10-punctata (15/20) Harmonia axyridis (18/20) 1 1 1 1 2 2 2 9 39 47 52 52 791 0 100 200 300 400 500 600 700 800 900 No adults/ 1540 beatings Figure 2. Numbers of adult ladybirds collected. In brackets: number of sites in which they were caught. An even lower number of species was present as larvae (Figure 2). Again, H. axyridis was the dominant species, present in all sites with 737 larvae. To the contrary, only 33 native coccinellids larvae (C. quatuordecimguttata, Adalia spp., C. decemguttata and P. quatuordecimpunctata) were collected in 7, 5, 2 and 1 out of 20 sites, respectively. All these aphidophagous species are in competition for food and are potential intraguild prey for H. axyridis.
Unidentified (9/20) Propylea 14-punctata (1/20) Calvia 10-guttata (2/20) Adalia spp (5/20) Calvia 14-guttata (7/20) Harmonia axyridis (20/20) 1 3 17 9 20 737 0 100 200 300 400 500 600 700 800 No larvae/ 1540 beatings Figure 2. Numbers of ladybird larvae collected. In brackets: number of sites in which they were caught. Alkaloid contents The analysis of 590 H. axyridis larvae collected on lime trees revealed exogenous alkaloids in 21% larvae coming from all of sampled sites, except for one site (LEO) (Figure 3). Positive larvae contained mainly one alkaloid but in 6% of the positive larvae, two alkaloids were detected in each individual, resulting from double predation on two different coccinellid genera. Three exogenous alkaloids were identified in the H. axyridis larvae analysed: adaline, propyleine and calvine. They are naturally present in Adalia spp., in P. quatuordecimpunctata, and in Calvia spp. (Laurent et al. 2005). The detection of these exogenous alkaloids in H. axyridis larvae confirms the existence of intraguild predation on these native species in the field. No H.axyridis larvae analysed 90 80 70 60 50 40 30 20 10 0 LEO BAR 0 Exogenous alkaloid (-) 1 Exogenous alkaloid (+) 2 Exogenous alkaloids (++) CHA VUB BAS SOL PAP MEL PLA ROS TEN CLE FOR Figure 3. Numbers of H. axyridis larvae with (black and grey) and without (white) exogenous alkaloids in each site. FLA DEN DIE PRA TRI WOL CAM 33
- Page 1: Science Facing Aliens Proceedings o
- Page 4 and 5: Segers, H & E. Branquart (Eds). Sci
- Page 7 and 8: Welcome to the World? Non-native br
- Page 9 and 10: these geese species exchange betwee
- Page 11: References Anselin A., Geers V. & K
- Page 14 and 15: 8 variables, hydro-morphological ch
- Page 16 and 17: 10 References Bollache, L., Devin,
- Page 18 and 19: 12 Figure 1 - USDA hardiness zones
- Page 20 and 21: 14 40 35 30 25 20 15 10 5 0 # of bl
- Page 22 and 23: 16 Appendix - List of non-native sp
- Page 25 and 26: Impact of Fallopia spp. on ecosyste
- Page 27 and 28: thermophilous grassland species. Ba
- Page 29 and 30: Soil-dependent growth strategy of i
- Page 31 and 32: Nr. of flowers/plant 3.0 2.5 2.0 1.
- Page 33 and 34: Detection of intraguild predation b
- Page 35 and 36: Adaline (µg) ± S.E. 2.50 2.00 1.5
- Page 37: Measuring the impact of Harmonia ax
- Page 41 and 42: Comparing Fallopia japonica, F. sac
- Page 43 and 44: SLA (m²/kg) 30 25 20 15 10 5 0 SLA
- Page 45 and 46: Mediterranean container plants and
- Page 47 and 48: All species from our survey have in
- Page 49 and 50: dangers of uncritically using the t
- Page 51 and 52: Water frogs in Wallonia: genetic id
- Page 53 and 54: • the distinction between the nat
- Page 55: References Berger, L., 1988. On the
- Page 58 and 59: 52 # crabs fyke -1 day -1 150 100 5
- Page 60 and 61: 54 Ring-necked parakeets in Belgium
- Page 62 and 63: 56 Our models predict a mean number
- Page 64 and 65: 58 Strubbe D. & Matthysen E., 2009c
- Page 66 and 67: 60 Study area & data collection Lie
- Page 68 and 69: 62 cm) and age of the tree and comp
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- Page 75: References Armbrecht I., Perfecto I
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- Page 87 and 88: Brussels Psittacidae: impacts, risk
Unidentified (9/20)<br />
Propylea 14-punctata (1/20)<br />
Calvia 10-guttata (2/20)<br />
Adalia spp (5/20)<br />
Calvia 14-guttata (7/20)<br />
Harmonia axyridis (20/20)<br />
1<br />
3<br />
17<br />
9<br />
20<br />
737<br />
0 100 200 300 400 500 600 700 800<br />
No larvae/ 1540<br />
beat<strong>in</strong>gs<br />
Figure 2. Numbers of ladybird larvae collected. In brackets: number of sites <strong>in</strong> which they<br />
were caught.<br />
Alkaloid contents<br />
The analysis of 590 H. axyridis larvae collected on lime trees revealed exogenous alkaloids <strong>in</strong><br />
21% larvae com<strong>in</strong>g from all of sampled sites, except for one site (LEO) (Figure 3). Positive<br />
larvae conta<strong>in</strong>ed ma<strong>in</strong>ly one alkaloid but <strong>in</strong> 6% of the positive larvae, two alkaloids were<br />
detected <strong>in</strong> each <strong>in</strong>dividual, result<strong>in</strong>g from double predation on two different cocc<strong>in</strong>ellid<br />
genera.<br />
Three exogenous alkaloids were identified <strong>in</strong> the H. axyridis larvae analysed: adal<strong>in</strong>e,<br />
propyle<strong>in</strong>e and calv<strong>in</strong>e. They are naturally present <strong>in</strong> Adalia spp., <strong>in</strong> P.<br />
quatuordecimpunctata, and <strong>in</strong> Calvia spp. (Laurent et al. 2005). The detection of these<br />
exogenous alkaloids <strong>in</strong> H. axyridis larvae confirms the existence of <strong>in</strong>traguild predation on<br />
these native species <strong>in</strong> the field.<br />
No H.axyridis larvae analysed<br />
90<br />
80<br />
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
LEO<br />
BAR<br />
0 Exogenous alkaloid (-)<br />
1 Exogenous alkaloid (+)<br />
2 Exogenous alkaloids (++)<br />
CHA<br />
VUB<br />
BAS<br />
SOL<br />
PAP<br />
MEL<br />
PLA<br />
ROS<br />
TEN<br />
CLE<br />
FOR<br />
Figure 3. Numbers of H. axyridis larvae with (black and grey) and without (white) exogenous<br />
alkaloids <strong>in</strong> each site.<br />
FLA<br />
DEN<br />
DIE<br />
PRA<br />
TRI<br />
WOL<br />
CAM<br />
33
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