New Developments in Conservation Biocontrol
Felix Wäckers
Types of Biological Control
1. Classical Biological Control Introduction of ecologically adapted natural enemies from the area of origin of the (invasive) target pest .
2. Augmentative Biological Control Releasing mass-reared natural enemies.
3. Conservation Biological Control Conservation of naturally occuring predators or parasitoid within their ecosystem using cultural practices or habitat management to support their population development or enhance their activity.
Augmentative Biological Pest Control over Time
Number of commercially available natural enemy species The Future of Biocontrol: more and more products?
Continuing need for new natural enemies New approach: Smart tools and strategies to make biocontrol agents perform better
This man is fast...
This man is faster Resource Requirements
- Alternative Prey - Non-Prey Food - Nectar - Pollen - Plant Sap - Oviposition Sites - Shelter - Overwintering Sites
Resource Requirements
- Alternative Prey - Non-Prey Food - Nectar - Pollen - Plant Sap - Oviposition Sites - Shelter - Overwintering Sites
Methods to Provide Resources
- Landscape Managements
- Mechanical Application
- Plant Breeding
Many predators are nectar/pollen feeders
Type Plant- Arthropod examples can be found within: Type of plant Reference feeding food utilised stage Life-history adult Neuroptera: Chrysopidae (green lacewings) nectar, pollen (Stelzl 1991) omnivory Diptera: Syrphidae (hoverflies) nectar, pollen (Hickman et al. 1995) Cecidomyiidae (gall midges) nectar (Opit 1997) Tachinidea (parasitoid flies) nectar (Gilbert and Jervis 1998) Hymenoptera: Ichneumonidae, Braconidae, nectar (Jervis 1998) a.o. (parasitoid wasps) nectar (Lewis 1998) Vespidae (social wasps) nectar, fruit (Cuautle and Rico-Gray 2003) Formicidae (ants) nectar (Beattie 1985) Coleoptera: Meloidae (blister beetles) nectar, pollen juvenile Heteroptera: Pentatomidae (stink bugs) plant-juice
Temporal adult Hymenoptera: Ichneumonidae, Braconidae, nectar (Jervis 1998) omnivory a.o. (host feeding parasitoids) (Wackers 2003) Coleoptera: Cicindelidae (tiger beetles) seeds (Zerm and Adis 2001) juvenile Araneae: Araneidae (orb web spiders) pollen (Smith and Mommsen 1984)
Permanent adult & Acari:Mesostigmat Phytoseiidae nectar (van Rijn and Tanigoshi 1999a) omnivory juvenile (predatory mites) pollen (van Rijn and Tanigoshi 1999b) Heteroptera: Pentatomidae (stink bugs) plant juice (Ruberson et al. 1986) Miridae (mirid bugs) plant juice (Gillespie and McGregor 2000) Geocorinae (big-eyed bugs) plant juice Eubanks & Styrsky, this vol. Anthocoridae (flower bugs) pollen Eubanks & Styrsky, this vol. Neuroptera: Chrysopa, Hemerobiidae nectar, pollen (Stelzl 1991) (brown lacewings) (McEwen et al. 1993) Thysanoptera: Aeolothripidae, Phlaeothripidae leaves, pollen (Kirk 1997) Coccinellidae (ladybirds) nectar (Pemberton and Vandenberg Coleoptera: Carabidae (ground beetles) pollen 1993) seeds (Cottrell and Yeargan 1998) (Goldschmidt and Toft 1997) Resource Bottleneck: Lack of nectar and pollen in many cropping systems ConsumerThe impact benefits of nectar sources on biocontrol efficacy
30 Control 1 (N=6)
25 Control 2 (N=5) Nectar 1 (N=6)
20 Nectar 2 (N=6)
15
10
5 average number parasitized caterpillars parasitized number average
0 5 10 15 20 25 30 35 40 age wasp [days] Winkler et al., (2006) Landscape Management Agri Environment Schemes
Agriculture Environment
Focus on conservation Perceived Conflict Agri Environment Schemes
Agriculture Environment
Focus on ecosystem services
€320 billion/year €90 billion/year (Constanza 1997)
How to optimize services?
Traditional paradigm: Enhance diversity (diversity = stability = services)
Pimentel, D. (1961) Diversity-Stability hypothesis: The stability of a community increases with increasing biological diversity Does it work? Example biological pest control Andow D.A. (Ann. Rev. Entomol. 36: 561-586) Vegetational diversity and pest control
Effects variable
• 52% of published studies on agroecosystem diversification report reduced pest populations • 33% had no effect or variable effects • 15% resulted in increased pest populations. How to optimize services?
Traditional paradigm: Enhance diversity Functional biodiversity: Selectively enhance diversity Focus on functional groups that provide ecosystem services
Targeted landscape management
Informed selection of non-crop plants as a multifunctional tool to optimize ecosystem services
- Select plants that optimize biological pest control or pollination
- Select plants that avoid stimulation of pests
- Select plants that generate multiple ecosystem services (Wäckers, 1996, 2004)
Accessible Inaccessible
nectar nectar Attractive
Aegopodium podagraria Vicia sativa Leucanthemum vulgare Galium mollugo
Select to optimize BC benefits
Daucus carota Trifolium pratense Medicago lupulina Trifolium repens
attractive
- Non
Origanum vulgare Erigeron annuus Achillea millefolium (Wäckers and van Rijn, 2012) Select plants that optimize biological pest control
Choice Longevity (AFLI) Floral Hoverfly Hoverfly Lacewing References parasitoids family species Nectar Parasitoids E. balteatus E. balteatus C. carnea (species) depth Apiaceae Ammi majus 0 + + + - Geneau et al., unpubl. (Microplitis mediator) Apiaceae Coriandrum sativum 0 + + +/- Vattala et al., 2006 (Microtonus hyperodae) Apiaceae Daucus carota 0 +/- + ++ + Winkler et al., 2009 (Cotesia glomerata) Apiaceae Foeniculum vulgare 0 + + + Winkler et al., 2009 (Cotesia glomerata) Apiaceae Heracleum spondylium 0 +/- + +/- Winkler et al., 2009 (Cotesia glomerata) Apiaceae Pastinaca sativa 0 + + ++ +/- Foster & Ruessink, 1984 (Meteorus rubens) Polygonaceae Fagopyrum esculentum 0 + + + + Winkler et al., 2009 (Cotesia glomerata) Boraginaceae Borago officinalis 0 - + ++ - Nilsson et al., unpubl. (Trybliographa rapae) Ranunculaceae Ranunculus acris 0 + + - Kehrli & Bacher, 2008 (Minotetrastichus frontalis) Caryophyllaceae Gypsophila elegans 1 +/- + ++ Asteraceae Matricaria chamomilla 1 +/- + + - Nilsson et al., unpubl. (Trybliographa rapae) Asteraceae Achillea millefolium 1 +/- + +/- - Wäckers 2004 (Cotesia glomerata) Asteraceae L Cichorium intybus 1 - - + Asteraceae Chrysanthemum segetum 2 +/- + + Asteraceae Anthemis tinctoria 2 - +/- +/- Asteraceae Leucanthemum vulgare 2 +/- + - Wäckers 2004 (Cotesia glomerata) Asteraceae Tanacetum vulgare 2 - - +/- Asteraceae Calendula officinalis 3 - - Rahat et al., 2005 (Trissolcus basalis) Asteraceae Centaurea cyanus (+EFN) 3 +/- + ++ +/- Winkler et al., 2009 (Cotesia glomerata) Asteraceae Helianthus annuus (+EFN) 3 + + Asteraceae Cosmos bipinnatus 4 - - +/- + Rahat et al., 2005 (Trissolcus basalis) Malvaceae Malva sylvestris 4 - - - Boraginaceae Phacelia tanacetifolia 4 +/- +/- +/- - Irvin et al., 2007 (Gonatocerus spp.) Fabaceae Medicago sativa 4 - - - Kehrli & Bacher, 2008 (Minotetrastichus frontalis) Fabaceae Vicia sativa (+EFN) 4 - + ++ Geneau et al., unpubl. (Microplitis mediator) Fabaceae Lotus corniculatus 4 - -
Selecting plants that avoid stimulation of pests
(Winkler et al., 2009)
20 Pest 18
16
14
12
10
survival (days) survival Pieris rapae 8 Cotesia glomerata
6
4 Biological control agent 2
0
Medicago sp. Control (water) Daucus carota Centaurea jacae Origanum vulgareOrnithopus sativus Trifolium pratenseCentaurea cyanus Anethum graveolens Fagopyrum esculentum
Selecting plants that generate multiple ecosystem services Pollination Biocontrol Pollinator mix
Biocontrol mix
Combination (Campbell, Biesmeijer Varma & W ä ckers, ckers, 2012)
Taking it to the Farmer FAB (Functional Agrobiodiversity) Large scale biodiversity project in the Hoekse Waard working with conventional growers. Addition of annual and perennial field margins to existing landscape features (polders, dikes, creeks, canal borders).
Brussels Sprouts Cabbage aphids
80 Melige Koolluis Veld nabij akkerrandControl met: Cabbage aphids (aantal/plant) VetchBroad bean 60 Tuinboon Mixed flowers BloemenMixed flowers 40
20
0 24 26 28 30 32 34 36 week Three year trends in aphid and natural enemy populations at conventional farms aphids 7 8 farm 6 aphidsbladluizen bedrijf A aphids 6 A 5 B B 4 C 4 C
3 D D no./leaf
2 aantal/halm 2 1 0 0 2005 2006 2007 2005 2006 2007 1.0 0.4 predator/prey Predator/preyrover/luis 0.8 0.3 0.6 0.2 ratio 0.4
0.2 verhouding 0.1 0.0 0.0 2005 2006 2007 2005 2006 2007 Potato Wheat Aphid peak: mid July mid June Optimizing Ecosystem Services in Terms of Agronomy and Conservation (ECOSTAC.CO.UK)
Growing Wild Beneficial insects in field margins
300 June - Sept 2010 Insects observed in flowering field margin Insects observed in grassy margin 250
200
150
100
Mean insects observed insects Mean 50
0 Hoverflies Bumble bees Parasitoid w asps Ladybirds Beneficial insect group
250 June-Sept 2011 Insects observed in flowering field margin Insects observed in grassy field margin 200
150
100
Mean insects observed insects Mean 50
0 Hoverflies Bumble bees Parasitoid w asps Ladybirds Beneficial insect group Aphids in peas
0.8 70 Aphid % distribution 0.7 % parasitism 60
0.6 50 0.5 40 0.4 30
0.3 % parasitism % 20 0.2
Proportional aphidProportionaldistribution 0.1 10
0 0
08.06 15.06 22.06 29.06 06.07 08.06 15.06 22.06 29.06 06.07 08.06 15.06 22.06 29.06 06.07 CF1 - CF2 - CF3 Sample site and date The positive spiral
More beneficials Fewer pests More biodiversity
Fewer pesticides Yield impact? wheat (yield in tonnes/ha) 10
9
8
7
6
5 +12%
4
3
2
1
0 1 2 3 peas (yield in tonnes/ha) 7
6
5
4 +26%
3
2
1
0 1 2 3 carrots (yield in tonnes/ha) 9
8
7 6 +32% 5
4
3
2
1
0 1 2 3 Functional Biodiversity
• Shows that yield and conservation are not conflicting objectives • Helps growers cope with ongoing decline in pollinators and reduced availability of registered agrochemicals • Compatible with current practices • Creates additional economic incentives for farmers to engage in Agri-Environment Schemes • Makes CAP greening a win-win for farmers and nature
artificial sugar sources Artificial food sprays: Sugar sprays in citrus to support Aphytis melinus
IVIA Alejandro Tena
42 Artificial food sprays: Sugar sprays in citrus to support Aphytis melinus
• California red scale is most important pest in citrus • Aphytis melinus is thought to be the key parasitoid • Natural populations provide insufficient control • Parasitoid releases? • Sugar supplements?
43
Sugar sprays in citrus to support Aphytis melinus
Do releases increase parasitoid density? 45
40 Control
35 30 25
20 tree (160 leaves) (160 tree 15
10 Aphytis / Aphytis 5 0 1 2 3 4 5 6 7 8 9 10 Day
44
Sugar sprays in citrus to support Aphytis melinus
Do releases increase parasitoid density? 45 SueltasReleases 40 Control 35 30 25
20 tree (160 leaves) (160 tree 15
10 Aphytis / Aphytis 5 0 1 2 3 4 5 6 7 8 9 10 Day
parasitoid emergence
45
Sugar sprays in citrus to support Aphytis melinus
Do releases + sugar increase parasitoid density? 45
40
35 30 25 Releases + sugar provision 20 tree (160 leaves) (160 tree Releases - sugar 15
10 Aphytis / Aphytis 5 0 1 2 3 4 5 6 7 8 9 10 Day
parasitoid emergence
46
Sugar sprays in citrus to support Aphytis melinus
3,5 Do sugars increase parasitism?
3,0 * / fruit/
2,5 = 30% parasitism
2,0
Aphytis 1,5 parasitism 1,0
0,5 Immature 0,0 Control Releases Releases + sugars
+ +
+
F 2, 194 = 4.45; P = 0.013 47
Sugar sprays in citrus to support Aphytis melinus
Conclusions: • Parasitoid releases result in limited and short-term increase of Aphytis melinus above background levels • Increase in parasitoid levels is more pronounced and more prolonged when releases are combined with sugar sprays • Food supplements can be an essential tool for existing and new biocontrol applications
48 Spraying Food Supplements
• Pollen Better establishment and rapid population growth even before pests arrive!
2/02/2017 Nutrimite
- Nutrimite has a well balanced nutrient profile
Protein Starch Other Carbs 20.6 30.6 18.9
- It is relatively resistant to mould/high humidity
- It is not collected by bees
- Nutrimite is based on Typha pollen, so no issues with pesticide residues
- After application, Nutrimite keeps its nutritional value for two weeks
- Nutrimite is relatively unsuitable for thrips
- As the pollen grains are large, Nutrimite settles quickly and causes little allergy problems
2/02/2017 NutrimiteTM Advice
Dosage 500 g / ha / application (0,45 lbs / acre / application) Interval Every 2 weeks
N° of applications min. 2-3 times, depending on predatory mite density Application method
To dust Use:
Effect of nutrimite on A. swirskii in Calathea
Pijnakker & De Souza, Biobest A. swirskii, Roses
Juliette Pijnakker, Biobest
Result:
- 2,5 times more predatory mites after 1 introduction & 3 Nutrimite applications
as compared to 3 introductions! Belgium Biobest
et al.
J.,Bron: Pijnakker, Conclusion
With Nutrimite: Less is more!
Fewer predatory mites needed per release and fewer releases required
Yet larger and healthier predatory mite populations
Better Biocontrol
Fibers What is the function of plant hair?
2/02/2017 Acarodomatia Not all plants are hirsute Citrus
• absence of trichomes on the leaves • Pollen and nectar only temporarily available Natural FIBERS
Comparison of different types
2/02/2017 Natural FIBERS
■ no choice-tests
2/02/2017 Natural FIBERS
2/02/2017 Fibers: Semi Field
Treatments (Manual) No fibers Fibers on top of leaf Fibers on underside
2/02/2017 Testing (combined) impact of pollen, sugar and fibers (Tolis Pekas)
O Control 1 eg fibers
2 3 eg fibers + sucrose Fibers + sucrose + pollen Euseius stipulatus: 20 females released per plant a
b mean (± SE) eggs per leaf
c c
a mean (± SE) motiles per leaf
b
b b Synergies
2/02/2017 2/02/2017
Breeding for Biocontrol?
The active role of the plant
• Plant-mediated pest-pest interactions • Plant-mediated pest-predator interactions
2 February 2017 Plant resistance mechanisms
Direct resistance Indirect resistance Breeding for indirect resistance? The example of extrafloral nectar Examples of crops with extrafloral nectar
Comparison of rose varieties
Feltiella acarisuga
Rose variety Efficacy of spider mite control Bianca - Delphi - Taxi - Aroma -
Costa + Easy Lover + Bi purple + Bi orange + Feltiella acarisuga
Rose variety Efficacy of spider mite control Nectar (in μl per 100 leaves) Bianca - 0.1 Delphi - 1 Taxi - 0.3 Aroma - 1
Costa + 1 Easy Lover + 2.5 Bi purple + 5 Bi orange + 5 Thanks