Distribution patterns of fungal entomopathogens in soil habitats:
Natural occurrence, diversity, dynamics
Nicolai V. Meyling
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 1 Assessing diversity in soils •Isolation methods
Patterns of distribution •Agricultural vs. natural habitats •Horizontal distribution
Dynamics of soil reservoir •Cycling between below and above ground environments
Molecular characterization •Species identification •Emergent patterns and implications
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 2 Natural occurrence on fungal entomopathogens in soil habitats – why ?
Reservoir and buffer environment
• Natural enemies – targets for conservation biological control strategies
• Effects of management practices on fungal populations
• Find indigenous isolates for biological control
• Predict effects of augmented biocontrol strains
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 3 Isolation from soil environment
Insect bait methods • Entomopathogenic isolates • Standardized approach? • Which insects?
Selective in vitro media • Detection levels? • How selective?
”… the Galleria bait method tends to be more sensitive that the (in vitro) isolation method.”
From Keller et al. (2003) BioControl , 48, 307-319
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 4 Conidiobolus coronatus
Isaria fumosorosea Metarhizium anisopliae
Metarhizium flavoviride Beauveria bassiana
Isaria farinosa Hirsutella SIP Utah 2009. Fungus Divisionnodulosa Symposium 'Fungi in Soil Habitats' Slide 5 Host range and specialization
ii rt . is ia a pp id n an s h ng si a ap o s se o br ba ll ne a a e a ri ri gw r e e n do uv uv ro n a a St Pa Be Be
Specialist Generalist
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 6 Host range: using the target pest
Tolypocladium Metarhizium Beauveria cylindrosporum anisopliae bassiana
Delia floralis (Diptera) + + -
Galleria mellonella (Lepidoptera) - + +
Based on Klingen et al. (2002) Agriculture, Ecosystem and Envrionment , 91, 191-198
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 7 Host range: baiting for Entomophthorales
Cereal field Grass Beneath Bird Cherry trees Pandora neoaphidis ++ + +
Conidiobolus obscurus + + +
Based on Nielsen et al. (2003) Biological Control , 28, 92-100
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 8 Temperature: baiting conditions
Habitat and Fungus 18 oC 25 oC
Forest soil M. anisopliae 0 % 7 % B. bassiana 1 % 12 %
Agricultural field M. anisopliae 5 % 38 % B. bassiana 53 % 10 %
Fallow field M. anisopliae 35 % 80 % B. bassiana 18 % 0 %
Based on data from Mietkiewski and Tkaczuk (1998) IOBC/WPRS Bulletin , 21 (4), 41-44
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 9 Distribution of fungal entomopathogens: habitat associations
•Which species in which habitat? •We define the habitats and characteristics •We define the parameters – are they important from the fungus point-of-view? •Correlations = causation?
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 10 Frequency of occurrence (%) Country Fungus Cultivated ”Natural” Reference habitat habitat Denmark 55 oN Steenberg (1995) B. bassiana 38.5 52.9 M. anisopliae 51.3 7.8 I. fumosorosea 2.6 9.8 Finland 62 oN Vänninen (1995) B. bassiana 5.6 28.1 M. anisopliae 14.9 24.2 I. fumosorosea 0.5 1.7 UK 52 oN Chandler et al. (1997) B. bassiana 1.0 7.7 M. anisopliae 1.0 1.3 I. fumosorosea 0.0 3.3
Canada 45 oN Bidochka et al. (1998) B. bassiana ~35 ~65 M. anisopliae ~63 ~36
o Sun et al. (2008) China 40 N B. bassiana 27.4 86.3 M. anisopliae 60.0 26.4 I. fumosorosea 15.6 37.5
o Spain 40 N B. bassiana ~34 ~53 Quesada-Moraga et al. (2007) SIP Utah 2009.M. Fungus anisopliae Division Symposium 'Fungi~10 in Soil Habitats' ~4 Slide 11 Habitat associations: regional scales
•”Natural” habitats B. bassiana and I. fumosorosea •Agricultural fields M. anisopliae
•Many ”similar” habitats sampled Comparability assumed •Generalizations from regional scales? Local scale diversity?
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 12 Locality specific diversity and distribution: Denmark
Taastrup (Bakkegården)
Årslev
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 13 Taastrup, Bakkegården 2002
B. bassiana dominating in field
100 B. bassiana 90 80 M. anisopliae 70 M. flavoviride 60 I. farinosa 50 I. fumosorosea 40 30 20
Frequency of occurrence of Frequency 10 0 Agricultural field (n=270) Hedgerow (n=70) Soil type
From Meyling and Eilenberg (2006) Agriculture, Ecosystem and Envrionment , 113, 336-341
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 14 Årslev 2006
100 90 Beauveria M. anisopliae I. fumoso. 80 70 60 50 40 30 20 Frequency of occurrence Frequencyof 10 0 Field A Field B Field C Hedgerow
Unpublished data
M. anisopliae dominating in field
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 15 Agricultural practices: conventional vs. organic (Årslev)
May 2007 Sept. 2007 M. anisopliae Beauveria spp. M. anisopliae Beauveria spp. 100 100
80 80 N.S. P=0.0485 60 60
40 40
20 20 Percent positive samples Percent Percent positive samples Percent 0 0 Conventional Organic Conventional Organic
May 2008 Sept. 2008
100 M. anisopliae Beauveria spp. 100 M. anisopliae Beauveria spp. 90 90 80 80 70 P=0.0406 70 60 60 N.S. 50 50 40 40 30 30 20 20 Percentsamples positive Percent positive samples Percent 10 10 0 0 SIPConventional Utah 2009. Fungus Division Symposium Organic 'Fungi in Soil Habitats' Conventional Organic Slide 16 Horizontal distribution within a site
•Where to sample ? •Identification of patches •Size of patches: distance between samples •When do we have enough samples ? •Patch dynamics ?
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 17 Horizontal distribution within a site: Bakkegården
Taastrup (Bakkegården)
Meyling and Eilenberg (2006) Agriculture, Ecosystem and Envrionment , 113, 336-341 SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 18 GIS coordinates (n=274) Location by GPS
550
500
450
400
350
B. bassiana : spatial statistics 300 m 250 Vj = -1.686; p = 0.0012
200 Vi = 1.772; p = 0.0003 150
100 Significant clustering Patch=red 50 Gap=blue 0 0 50 100 150 200 250 300 350 400 450 500 SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' m Slide 19 15 Meyling and Eilenberg (2006) Agriculture, Ecosystem and Envrionment , 113, 336-341 Have we found the distribution pattern ?
550 - quadrates between original sampling points 500
450
400
350
300 m 250
200
150
100 Patch=red 50 Gap=blue 0 0 50 100 150 200 250 300 350 400 450 500 25 m m
From Meyling and Eilenberg (2006) Agriculture, Ecosystem and Envrionment , 113, 336-341
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 20 Percent positive samples from ’Patch ’ and ’Gap ’ quadrates
’Patch ’ ’Gap ’ Chi 2 P
25x25 (n=25) All fungi 84 36 12.00 0.0005
B. bassiana 68 16 13.88 0.0002
5x5 (n=50) All fungi 72 38 11.68 0.0006
B. bassiana 54 20 12.39 0.0004
From Meyling and Eilenberg (2006) Agriculture, Ecosystem and Envrionment , 113, 336-341
Reducing distance between sampling points confirmed results from the whole field assessment
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 21 Continuity of ’Patch ’ and ’Gap ’ quadrates 2003-2006
(n=25) 2003 2006 Chi 2 P
All fungi ’Patch ’ 84 96 2.00 0.1573
’Gap ’ 36 48 0.74 0.39
B. bassiana ’Patch ’ 68 80 0.9356 0.3334
’Gap ’ 16 32 1.7544 0.1853
Based on MSc thesis 2007 by Vibeke Ærø Hansen
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 22 Horizontal distribution at Bakkegården
550 •B. bassiana patches and gaps: 500 identified 450
400 persistent in time
350
300 •Why patches ? m 250 •Where to get representable
200 sample from this site?
150
100 Patch=red 50 Gap=blue 0 0 50 100 150 200 250 300 350 400 450 500 m
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 23 Fungal entomopathogens in soils: do they go above ground?
Same fungal species in soil and insects Are they really the same ? Do similar genotypes cycle below and above ground ?
Molecular identification Co-occurrence in time and space
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 24 Bakkegården – Beauveria spp. below and above ground
Beauveria bassiana morphospecies = cryptic species complex
•Single locality (hedgerow) •Local insect community •Host plants in hedgerow •Soil of hedgerow
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 25 Meyling et al. (2009) Molecular Ecology , 18, 1282-1293 Molecular diversity of Beauveria community
KVL 03-76 100 Eu_1 ARSEF 1628 N= 33 MAT1/2= 31:2 KVL 03-141 KVL 03-73 Eu_3 100 KVL 03-90 N=2 ARSEF 1185 MAT2 KVL 03-114 70 Eu_4 B. bassiana s.s. 100 KVL 03-117 clonal N=10 ARSEF 1848 MAT1
100 ARSEF 815 100 Eu_6 KVL 03-84 N=3 KVL 03-85 MAT1 100 100 KVL 03-92 Eu_5 clonal KVL 03-102 N=20 MAT2 100 JE 276 B. brongniartii KVL 03-91 KVL 03-125 KVL 03-107 Clade C ARSEF 4933 10 changes Meyling et al. (2009) Molecular Ecology , 18, 1282-1293
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 26 Beauveria clone cycling in the hedgerow
Hawthorn bug and beetle Anthomyiid flies
Phylloplanes
Grass bugs Nettle bugs Soil surface
B. bassiana B. bassiana Eu_4 Eu_5
Based on Meyling et al. (2009) Molecular Ecology , 18, 1282-1293
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 27 Beauveria bassiana dynamics
Dispersal by wind; Infection of hosts on Dispersal by rainsplash; aerial plant parts Dispersal by insect activity
Infection of epigeal hosts Cadavers: Soil surface Conidia production Conidia persistence in soil Infection of subterranean Radial hyphal growth hosts
Meyling & Eilenberg (2007). Biological Control 43: 145-155
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 28 Metarhizium anisopliae dynamics
- no above ground cycling?
Soil surface Infection of epigeal hosts Cadavers: Conidia production Conidia Infection of subterranean persistence hosts in soil
Rhizosphere competence ?
Meyling & Eilenberg (2007). Biological Control 43: 145-155
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 29 Fungal entomopathogen communities above and below ground
Årslev
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 30 Soil sampling and collection of arthropod fungus-cadavers
Below ground = above ground ?
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 31 High arctic environments - Greenland
Disko: I. farinosa B. bassiana T. inflatum Ritenbenk: I. fumosorosea I. farinosa B. bassiana Zackenberg: I. fumosorosea I. farinosa Danmarkshavn: I. fumosorosea I. farinosa B. bassiana
Unpublished data
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 32 Acknowledgements
SIP Utah 2009. Fungus Division Symposium 'Fungi in Soil Habitats' Slide 33