Natural Enemies Orienting
to Melanaphis sacchari
J.P. Michaud and Felipe Colares
Kansas State University
Sorghum – Sugarca...
Introduction
Are native predators pre-adapted to find SCA?
Or do they need to evolve novel responses to
find a novel prey?...
Materials & Methods
• Potted sorghum plants infested with EITHER
M. sacchari (SCA) or S. graminum (GB)
• 2 field locations...
The tree line cohort
The sorghum cohort
The tree line cohort
No.aphids/pot
Observation date
No colonies of either aphids species matured
Tree line cohort – major predators
Observation date
The sorghum cohort
No.aphids/pot
Observation date
No colonies of either aphids species matured
No.coccinellidadultsNo.chrysopidlarvae
The sorghum cohort – major predators
Observation date
C. carnea was the only dominant species equally present in both cohorts
No. arthropod life stage-days
Tree line cohort Sor...
No. arthropod life stage-days
Cohort 1 Cohort 2
Life stage GB SCA GB SCA
Lysiphlebus sp. adults 2 5 0 0
mummies 47 0 771 0...
Key Findings (data not shown)
• Relative suitability of SCA versus
GB as prey (lab studies)
• Tested: H. convergens, C. ma...
Key Findings
• No real differences in NE responses
to SCA vs. GB
• ‘Natural’ biocontrol of SCA
should evolve similar to GB...
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Natural enemies Orienting to Melanaphis sacchari

2016 Sorghum Sugarcane Aphid Research Exchange
Published on: Mar 3, 2016
Published in: Education      
Source: www.slideshare.net


Transcripts - Natural enemies Orienting to Melanaphis sacchari

  • 1. Natural Enemies Orienting to Melanaphis sacchari J.P. Michaud and Felipe Colares Kansas State University Sorghum – Sugarcane Aphid Research Exchange Meeting New Orleans, LA January 7 – 8, 2016
  • 2. Introduction Are native predators pre-adapted to find SCA? Or do they need to evolve novel responses to find a novel prey? Hypothesis: Aphid natural enemies will recruit more quickly and in larger numbers to a familiar prey (S. graminum) than to a novel prey (M. sacchari)
  • 3. Materials & Methods • Potted sorghum plants infested with EITHER M. sacchari (SCA) or S. graminum (GB) • 2 field locations (tree line vs sorghum monoculture) • All insects counted daily on all plants until aphid colonies consumed • Data tallied as ‘No. life stage-arthropod-days’
  • 4. The tree line cohort
  • 5. The sorghum cohort
  • 6. The tree line cohort No.aphids/pot Observation date No colonies of either aphids species matured
  • 7. Tree line cohort – major predators Observation date
  • 8. The sorghum cohort No.aphids/pot Observation date No colonies of either aphids species matured
  • 9. No.coccinellidadultsNo.chrysopidlarvae The sorghum cohort – major predators Observation date
  • 10. C. carnea was the only dominant species equally present in both cohorts No. arthropod life stage-days Tree line cohort Sorghum cohort Natural enemies Life stage GB SCA GB SCA Aphelinus sp. adults 0 4 8 4 mummies 22 41 771 319 Chamaemyiidae larvae 0 24 0 0 Chrysoperla carnea adults 3 12 10 34 eggs 194 609 204 401 larvae 3 19 35 97 Coccinellidae adults 0 3 58 64 egg masses 0 8 2 97 larvae 0 77 2 24 Erythraeus sp. (mite) nymphs 12 5 0 0 Hemerobiidae adults 0 0 0 1 eggs 0 181 0 0
  • 11. No. arthropod life stage-days Cohort 1 Cohort 2 Life stage GB SCA GB SCA Lysiphlebus sp. adults 2 5 0 0 mummies 47 0 771 0 Orius insidiosus adults 0 0 39 11 nymphs 0 0 104 22 Syrphidae adults 5 9 0 0 eggs 1308 1626 13 37 larvae 631 1278 33 60 pupae 0 5 0 1 Conclusion: There were more differences between locations than between aphid species in natural enemy recruitment
  • 12. Key Findings (data not shown) • Relative suitability of SCA versus GB as prey (lab studies) • Tested: H. convergens, C. maculata, C. carnea and O. insidiosis • Results: SCA was equivalent to GB, i.e. supported development and reproduction of these species just as well
  • 13. Key Findings • No real differences in NE responses to SCA vs. GB • ‘Natural’ biocontrol of SCA should evolve similar to GB • Efforts to conserve native NE’s will assist this process