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Population biology of Beauveria Dave Chandler, Gill Davidson University of Warwick

Population biology of Beauveria Dave Chandler, Gill Davidson University of Warwick. Insect pathology - the early years. Anamorphic Ascomycete Entomopathogenic fungi . Widespread in nature, especially soil. Range of species, different properties. Used as inundative biopesticides.

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Population biology of Beauveria Dave Chandler, Gill Davidson University of Warwick

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  1. Population biology of BeauveriaDave Chandler, Gill DavidsonUniversity of Warwick Insect pathology - the early years

  2. Anamorphic Ascomycete Entomopathogenic fungi • Widespread in nature, especially soil. • Range of species, different properties. • Used as inundative biopesticides. • Can be valuable components of IPM.

  3. Inundative biopesticides: development = chemical model. Ignoring ecological attributes (Waage) numerical response, trade offs, conservation control. Lack of knowledge: affects biocontrol efficacy & environmental risk evaluation. Chemical clones or bio-control agents?

  4. Ascomycete entomopathogenic fungi • Natural abundance? Diversity? Ecosystem function? • Are they ecologically obligate pathogens? • Determinants of population structure? • Population dynamics? • How does virulence evolve? • Lack meaningful species definitions. • Theoretical framework for predicting environmental (non target) impacts of biocontrol releases.

  5. Work outline • Studying natural popns. of fungi in soils, esp. Beauveria. • Bidochka : biogeography of Beauveria & Metarhizium. • Rehner:Beauveria phylogeny. • Expt 1: • Examined Beauveria from culture collection: collected from UK woodland & farm grassland. • Expt 2: • Sampling at a single farm site.

  6. Galleria bait method

  7. Culture collection: Beauveria isolates from 9 woods & 11 grasslands. Devon Somerset Gloucestershire Herefordshire Shropshire Berkshire Warwickshire Leicestershire Experiment 1: Beauveria biogeography?: national scale

  8. Culture collection: Isolates from each location. 117 total, 85 wood, 32 grass. Sequence data: EF1a 28s rDNA gp I intron Beta tubulin, rDNA ITS DNA lyase, Beta locus Micro satellites. Beauveria biogeography: national scale

  9. 88 63 100 100 98 100 100 EF1a woods & grassland (includes 1 sequence each from Rehner clades A – F) B. scarabaeicola EFCC2533 A :28/56 from woods (exp 41/56) B: 20/20 from woods (exp 15/20) C: 37 / 41 from woods (exp 30/41) D (B. caledonica) none E (Cordyceps sp.) none clustal W, distance (NJ) F (B. amorpha) none Chi sq : habitat effect : p < 0.001 (pearson = 28, 2 df)

  10. Expt 2: Fungi from different habitats in close proximity: Warwick Dept. farm Grassland 10 ha Stewardship 12 ha Arable 7 ha hedgerow

  11. Expt 2: Fungi from different habitats in close proximity Water meadows Long close Deep slade

  12. Frequency of occurrence (%) Chi square (pearson) 68.7, 9 df, p < 0.001

  13. EF1a Warwick dept farm Constructed tree (NJ, distance) with Beauveria isolates: Hedgerow 24 Arable 26 Stewardship 23 Grassland 26 Total 99

  14. EF1a Warwick dept. farm: hedge vs. fields (includes 1 sequence each from Rehner clades A – F) B. scarabaeicola EFCC2533 A :7/77 from hedge (exp 19/77) 96 64 B: 1/2 from hedge 100 100 97 C: 16 / 20 from hedge (exp 5/20) 100 D (B. caledonica) none 100 E (Cordyceps sp.) none clustal W, distance (NJ) F (B. amorpha) none Chi sq : habitat effect : p < 0.001 (pearson = 47, 6 df)

  15. Simplified conclusions • Genetic groups in Beauveria have different habitat preferences. Why? • Warwick farm study: • Habitat type affects frequency of occurrence of fungi. • Diff genera have diff habitat preferences?

  16. Why does this matter? • Bio-prospecting. • Conservation control (habitat manipulation). • Informs risk assessment. • Generation & maintenance of diversity in an ‘asexual’ organism.

  17. acknowledgements • USDA Steve Rehner

  18. Thanks for your attention!

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