Diapause manipulation in Harmonia Axyridis

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Diapause manipulation in Harmonia Axyridis

• Presented By
• Julia Harrison

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Introduction

• Harmonia Axyridis, A TYPE OF LADY BUG, enterS
  diapause OR A PERIOD OF DORMANCY, when there are
  extended periods of less than 16 hrs of light and
  temperatures less than 59f.

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INTRODUCTION

• While noticing the habits of the insects of
  discussion within MY OWN HOME, it became evident
  that the assumed conditions for the inducement of
  diapause were in need of testing.

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INTRODUCTION

• The vast numbers of these homebound insects were
  not appearing to adhere to the popularly provided
  parameters for the inducement of diapause. They
  were witnessed to be within a hibernatory state
  while remaining outside the parameters of full
  diapause.

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INTRODUCTION

• SO, In the attempt to determine if this was mere
  mortality or mistaken latitudes, specimens were
  collected and the said parameters were tested.

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Specimens and Method

• 60 insects were used 4 groups of 15 for a period
  of one week
• each group was placed in an aluminum bowl with a
  screen placed on top of it

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Group A

• Group a was kept in a room with a largely
  consistent temperature of eighty degrees and
  received twenty hours of light

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GROUP B

• GROUP B WAS given the same amount of light as the
  first group but WAS kept in a room that provided
  a temperature that dropped routinely below
  fifty-five degrees. This drop occurred five times
  within the week.

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GROUP C

• GROUP C WAS kept in a room of a mostly consistent
  temperature of seventy degrees and was provided
  with less than one hour of light a day.

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GROUP D

• GROUP D, the control group, was placed in the
  same apparatus in a refrigerator and therefore
  received neither of the diapause prohibiting
  variables little to no light and temperatures
  below fifty-nine degrees.

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RESULTS

• Group A nine insects displayed movement
• Group B six insects displayed movement
• Group C two insects displayed movement
• Group D zero insects displayed movement

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CONCLUSION

• The data suggests that entry into diapause is
  more dependent upon light than temperature, with
  temperature as a secondary constituent of
  convergence as here tested.

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CONCLUSION

• Temperature may become less secondary and/or
  convergent within temperatures lower than tested.
  Perhaps future study will examine the true
  vitality and threshold of temperature as a
  commanding variable.

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CONCLUSION

• It should also be noted that due to the
  relatively short time of the study, the plain
  mortality rate of the insects could not be
  measured. This, along with a somewhat small
  sample population, is a true liability of this
  study. Maybe future study can address this as
  well.