species preference in the pill bug (Armadillidium sp.) Emily Byrne Kevin Isherwood Greg McGuire Jonathan O’Keefe
Feb 09, 2016
Leaf litter species preference in the pill bug (Armadillidium
sp.)
Emily ByrneKevin Isherwood
Greg McGuire Jonathan O’Keefe
The pill bug, Armadillidium sp.
• Widespread terrestrial crustacean
• Susceptible to desiccation• Physiological adaptations• Behavioural adaptations
• Respiratory mechanisms
Habitat preference• Flexible diet comprised primarily of decaying
matter
• Moist, dark environments
• Decaying > fresh leaf litter
Species- specific leaf litter
• High quality litter> low quality litter• Panlasiui (2011)• Oak, Quercus agrifolia, > Blue Gum, Eucalyptus
globulus
• Tuck & Hassall (2003)• Dicotyledon litter > grass litter
• Morisawa et al. (2002)• Japanese Cedar, Cryptomeria japonica – natural
repellant
Current study
• Investigate if the pill bug, Armadillidium sp. has a preference for local leaf litter species
• Hypothesis: individuals will prefer broad-leaf species
Experiment 1: Leaf litter species preference
• 3 trials• Wet leaves• Dark
environment
20 pill bug
s
Picea rubens
Quercus rubens
Thuja occidentalis
Acer saccharum
_x0006_Spruce
_x0006_ Maple
_x0006_ Cedar
_x0004_ Oak _x0005_ Dead
0
1
2
3
4
5
6
7
8
9
10
Leaf litter species
Num
ber o
f pill
bug
s
Experiment 2: Effects of moisture and humidity
• Spruce dried in oven
• Maple dunked in well water
20 pill
bugs
Dry Spruce Wet Maple
0
5
10
15
20
25
Leaf litter condition
Num
ber o
f pill
bug
s
Discussion
• Hypothesis: preference for broad leaf species
• Drying of leaves potentially a major contributor
Discussion
• Cloudsley-Thompson & Constantinou 1987 • Presence of a thigmokinetic response
• Takeda 1980 • Possible aggregation pheromones
Questions?