What’s that Smell?Alyson McCroskey, Lauren Williams, Maggy

Gleason

What’s That Smell?Habitat Preference for

decorated crickets, Gryllodes sigillatus, based on predator olfactory cues from feces of

the Leopard Gecko, Eublepharis macularius.

Introduction:Predator avoidance may occur if prey can

detect predators early, which therefore may increase fitness. (Brettschneider & Bateman 2004).

Visual, acoustic, and olfactory cuesPredators may leave behind olfactory cues in

the form of feces. Feces supplies the prey with information about the threat status of a predator(Madison et al., 1999).

Introductions:Gryllodes sigillatus –

known as the decorated cricket.

Located in South Western United States

Common predators include; spiders, birds, mice, and lizards. (Kortet, R. & Hendrick A. 2004)

Introduction:Eublepharis

macularius- known as Leopard Gecko

Geckos orient themselves to the male cricket call, so they can consume the females that come looking for a mate. (Sakaluk & Belwood, 1984).

Introduction:Crickets may use olfactory cues to identify

predators in their habitats. Females use chemosensory cues to detect

males they have previously mated with to avoid mating with that male again.(Ivy et al., 2005).

Introduction: HypothesisIf crickets use olfactory cues to detect a

predator, then they would prefer habitats without the predator.

Prediction: When crickets are given a choice between two habitats, one with the presence of predator olfactory cues and one without, they will choose the habitat without the cue.

Methods:November 16, 2008 at Illinois State

UniversitySampled 30 male and 30 female decorated

crickets that were previously isolated into male and female containers for 1 week.

Trials were conducted during the dark phase of the photoperiod under red light illumination.

Feces was collected from 2 leopard geckos at University High School which are fed mainly meal worms, and sometimes crickets.

Methods:12 shoebox sized plastic containersSolution of Leopard gecko feces- 90 ml of tap

water and approximately 2 grams of crushed feces.

Cotton ballsOne zero sampling in 30 second intervals for

a total of 15 minutes

Display of Containers and Cotton Ball Positioning

Lab Set UP

Under Red Light

Methods: CalculationsStatistical analysis using a one – tailed t-test,

with a significance level of α = 0.05Calculations were done using proportions

Intervals spent on the side ÷ total number of intervals

Results: Male: t58= 1.51, P > 0.05Not Significant

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Male Crickets Habitat Preference

No Cue

Cue (Gecko Feces)

No Cue vs Cue

Pro

port

ion o

f T

ime

Results:Female: t58 = 4.79, P < 0.05 Significant

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Female Crickets Habitat Preference

No CueCue (Gecko feces)

No Cue vs. Cue

Pro

port

ion o

f T

ime

DiscussionOur hypothesis was not supported, male and

female decorated crickets did not spend a larger proportion of time on the side without the feces olfactory cue.

Both spent a larger proportion of time on the side with the feces olfactory cue.

Only significant in females

DiscussionPredator avoidance is less common in

invertebrates (Brettschneider & Bateman 2004).

In another experiment, Platygryllus primiformis, preferred shrew feces-treated habitat to a water treated habitat(Brettschneider & Bateman 2004)

Discussion:Females use olfactory cues for mating(Ivy et

al., 2005). Crickets raised in captivity, never exposed to

predatorsNovel smell, curiosity

DiscussionError: Geckos did not consume crickets

before feces samples were collectedPredator feces give off olfactory cues based

on the prey they consume. The prey can chemically label these cues as a high risk predator. (Madison et al., 1999).

Larger sample size and increase total time of experiment.

Discussion:Future experiments

Possible differences in the development of male and female sensory organs.

Test different sensory cues visual and auditory.

References: Brettschneider, H. & Bateman, P. 2004. Differential shelter selection in

response to predator chemical cues by two orthopterans: Libanasidus vittatus(Anostostomatidae) and Platygryllus primiformis (Gryllidae). Journal of Insect Behavior, 18: 381-387. 

Ivy, T. M., Weddle, C.B., Sakaluk, S.K. 2005. Females use self-referent cues to avoid mating with previous mates. Proceedings of the Royal Society of London

Series B, 272: 2475–2478.

Kortet, R. & Hendrick, A. 2004. Detection of the spider predator, Hololena nedra by naïve juvenile field crickets (Gryllus integer) using indirect cues. Behaviour 141: 1189-1196.

Madison, D.M., Maerz, J. C., and Mcdarby, J. H. 1999. Optimisation of predator avoidance by salamanders using chemical cues: Diet and diel effects. Ethology 105: 1073-1086

Sakaluk, S.K. & Belwood, J.J. 1984. Gecko Phonotaxis to cricket calling song: A case of Satellite Predation. Animal Behanivor, 32: 659-662.