Pollinators of the Jack-In-The-Pulpit (Arisaema triphyllum) Effects of Gender

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Pollinators of the Jack-In-The-Pulpit (Arisaema
triphyllum)Effects of Gender Disease

• Nicholas Ewy
• Andy Jarosz
• Michigan State University

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Arisaema triphyllum

• Herbaceous perennial.
• Damp woodland habitat
• Flowers April-June
• Females up to three feet tall,males smaller
• One or two trifoliate leaves
• One inflorescence, male or female
• Vegetative corms

Arisaema triphyllum
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Fruit Structure
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Distribution of A.triphyllum
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Arisaema triphyllum

• Sex changecurrent and previous size, reproduced
• Inflorescence color
• Inflorescence odor production
• Inflorescence acts as a kettle trap
• Selection against pollinator specialization
• Successful pollinators die

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Possible pollinator

• Very little research on pollinators
• Existing studies indicate the fungus gnat as a
  primary pollinator
• not very efficient or specialized.

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The jack in the pulpit Kettle trap and
pollination technique

• Insect enters male flower, falls to the bottom of
  the flower picking up pollen, escapes through
  small hole.
• Insect enters female in a similar fashion but is
  unable to escape and is forced to pollinate

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Uromyces ari-triphyli

• A specialized rust attacking the
  Jack-in-the-pulpit population
• Perennates in corm.Infects plant tissue during
  shoot expansion in the spring

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Hypothesis

• New study, develop basis for future research
• The majority of pollinators will be fungus gnats
• Males will have very few insects if any inside
  inflorescences.
• Females will have many trapped insects
• Diseased plants will have shorter flowering times
  and not very functional kettle traps, resulting
  in less pollinators.

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Project Objectives

• To Observe, document and collect pollinators
• Compare the differences in insect pollinators
  between the different populations
• Compare pollinators in male and female plants,
  and diseased and healthy plants

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Population sites
N
E
W
S
Isolated wood lots, surrounded by fields and
farmland
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Pollinator Observation

• Observed insect activity
• Record flower contact
• Pollination criteria
• Over 100 plants observed
• 21 hours of observations

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Entries

• Total number of entries was 17

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Results

• Only one true pollination observed. Resembled
  large house fly
• Constant insect activity around plants, including
  fungus gnats
• However, very few entries and pollinations
• Not enough data for disease or population
  comparisons.
• Wrong time of day? Different weather conditions?
  Too late in the season?

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Flower Dissection

• Collected inflorescences of diseased and healthy,
  male and female flowers
• Examined insect contents of each under dissecting
  microscope.
• Saved representative insects.

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Flower Dissection

• 54 flowers collected
• 170 insects found, roughly 3 insects per plant
• 25 representative insects found. Identified 13 of
  the 25

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Insect contents

• A Variety of flies mosquitoes, gnats, wasps and
  beetles
• predatory insects such as spiders, true bugs
• Good hunting area or refuge?

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Flower Dissection results

• 70 insects in bad condition, not categorized
• Decayed insect remains, and storage techniques

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Flower Dissection
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Flower Dissection Results
Populations have different habitats
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Spiders

• Surprising and significant discovery
• Many spiders found inside inflorescence
• Spider webs in 55 of flowers stored in freezer
• Insect carcasses found caught in webs

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Spider webs inside inflorescences
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The future

• New study, trial and error
• Good basis to guide future study
• Scientific questions
• Are there other effects of spiders with
  pollinators? Do they affect the amount of seed
  set? Why more in diseased flowers?
• Are the scents stronger in certain conditions do
  the dead insects create an attractive scent?
• How does flower color effect pollinators?
• How do the general insect populations differ at
  each site?
• Technical changes
• More hours of observation earlier in the season,
  especially after rainy weather
• immediate dissection, no storage.

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Thanks to Andy Jarosz and lab, Frank Ewers,
Jessica Cook, Erin Mason, Kelly Wessell