1. Rory McDonnell1, Amy Roda2 and Jocelyn Millar1
 Gastropod attractants: Potential management tool for  Giant African Land Snail Lissachatina fulica? RESEARCH UPDATE
Rory McDonnell1, Amy Roda2 and Jocelyn Millar1
1: Department of Entomology, University of California, Riverside
2: CPHST, USDA-APHIS, Subtropical Horticultural Research Station, Miami

2. Background External attractants e.g. from food sources
Chemical cues play roles in feeding, prey detection, predator avoidance, alarm responses, species recognition & reproduction in gastropods
External attractants e.g. from food sources
Possible pheromones
Sex pheromones
Aggregation pheromones

3. Sex pheromones
Ilyanassa obsoleta
Euhadra peliompha
exoticsguide.org
Photo: Wikimedia Commons
Spawning and breeding in mud snails organized by at least two kairomones and three pheromones
Gland in the head produces a pheromone that elicits courtship and copulation

4. Aggregation Pheromones
Lissachatina oriented towards odor of conspecifics
Source reported to be the pedal mucus gland
Attractant is a pheromone
Source: Chase (1978) 4

5. Why no further work to follow up?

6. Our Approach Attractants produced by conspecifics
Follow up on preliminary work by Chase from 1978, showing attraction of GAS to odors from conspecifics
Attractants from other sources
 Identify and develop attractants from other sources (e.g., food)

7. 1. Pheromones

8. Response of Lissachatina fulica to the odor of conspecifics
X2 = 24.69, P<0.001, n=20

9. Aeration chamber for collecting odors from live snails

10. Odor analysis results
Little difference between snail and control aerations
One compound appeared consistently in snail odor collections
2-diethylaminoethanol

11. Response of Lissachatina fulica to a 0
Response of Lissachatina fulica to a 0.01% solution of 2-diethlyaminoethanol
X2 = 6.14, P<0.05, n = 14

12. 2. Other attractants Fed snails a variety of different foods
With one food item, noticed a distinct oriented mass movement towards the food
Much more pronounced than normal, clearly strong attraction to odors from the food

13. Attraction to food odors
Pronounced oriented movement towards food source

14. Replicated bioassays Two choice bioassay Treatment
1ml of treatment and 1ml control on filter paper
Position of treatment and control switched after each replicate
Snails tested individually to prevent trail-following
Choice made when snail touched the Petri dish or after 45min
Treatment
Control

15. Response to steam distillate
X2 = 6.07, P<0.05, n = 10
Statistically significant attraction
Result: Attractants are extractable and heat stable

16. Response to ether extract of steam distillate
X2 = 6.07, P<0.05, n = 10
Statistically significant attraction
Result: Attractant extractable into organic solvent, easier to work with

17. Response to acid-treated steam distillate
X2 =6.00, P<0.05, n = 10
Statistically significant attraction
Result: Attractant cannot be amine or other organic base

18. Response to base-treated steam distillate
X2 = 7.00, P<0.05, n = 10
Statistically significant attraction
Result: Attractant cannot be organic acid

19. Response to neutralized ether extract of steam distillate
X2 = 20.20, P<0.001, n = 10
Statistically significant attraction
Result: Attractant is one or more neutral compounds in the steam distillate

20. Result: Attractant is a moderately polar compound
Response to methanol elution of steam distillate volatiles trapped on solid phase extraction cartridge
X2 = 8.32, P<0.05, n = 10
Statistically significant attraction
Result: Attractant is a moderately polar compound

21. Conclusion
The attractant is a heat-stable neutral compound(s) that is moderately polar
Some attraction to a partial reconstruction of the compounds in the neutrals fraction

22. Next steps! Pheromone: 1. Continue to analyze the aeration extracts
2. Testing of pedal mucus gland

23. Next steps! Food based attractant:
1. Analysis of the neutrals fraction from the steam distillate
2. Development of a fractionation scheme
3. Reconstruction of the volatiles blend for bioassays

24. Questions?
Acknowledgements:
 APHIS-PPQ-CPHST for funding to date