Behavioral Responses of Common Pill bugs Armadillium vulgare to Changes in Humidity

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Behavioral Responses of Common Pill bugs
(Armadillium vulgare) to Changes in Humidity
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Purpose

• To observe habitat selection of terrestrial
  isopod in a humidity gradient chamber
• To demonstrate thats animal response to humidity
  gradient caused by a change in its locomotor
  activity

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Armadillidium vulgare

• Classification Phylum Arthropoda Class
  Malacostraca Order Isopoda Family
  Armadillidiidae
• Physical Characteristics Mass 0.05 to 1.0
  g, 3/4 in Shell-like exterior
  Color gray to brown Five abdominal
  segments 7 pairs of legs, 1 pair of antenna,
  1 pair of compound eyes

• Habits Live outdoors
  Biomes temperate forest
  rainforest, temperate grassland Omnivores
  Group in masses to reduce
  water loss Most active at
  night Reproduce on land
  Grow by molting Defense mechanism
  curling into a tight ball
  Distribution affected by moisture content
  

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Part I Humidity Gradient Chamber

• High Humidity Area wet paper towels
• Low Humidity Area anhydrous calcium chloride
  10
  individuals observed per chamber

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Average Number of Pill bugs Observed at Certain
Time
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Total Number of Pill bugs Observed in Three
Chamber Areas
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Part IIMovement of Pill bugs Under Different
Humidity Conditions

• High Humidity Chamber moist wood shavings
• Low Humidity Chamber anhydrous calcium chloride

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Number of 1 cm Squares Crossed in 5 Minutes
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Conclusion

• Habitat preference
  Moist environment -orientation
  due to moisture gradient -breathing
  through gill-like structures
• Kinesis
  As relative humidity of
  environment increases the amount of time the
  animal is stationary also increases.
  The more the animal moves the greater the
  chance that it will find a moist area.