Dispersal and control of the banded wood snail, Cepaea nemoralis.shell

Merritt Gillilland
Department of Zoology
Michigan State University
  
    My doctoral research was focused on using harmonic radar (see pics below) to better understand the dispersal ecology of banded wood snail, Cepaea nemoralis, in southern Michigan.  I used harmonic radar to track the daily movements of snails in their natural environment. 
    
    The banded wood snail is an exotic, invasive, and pest species from Europe.  It was brought to North America in 1857 by Dr. W.G. Binney and released in New Jersey.  It is slowly spreading throughout the U.S.  The most likely form of long-distance dispersal responsible for the spread of this organism is anthropogenic (human) dispersal.  Very little is known about the natural short-distance dispersal of Cepaea nemoralis.  I can correlate the detailed movements of Cepaea nemoralis to many abiotic (temperature and relative humidity) and biotic factors at the microhabitat level.  It is also possible to compare the dispersal of Cepaea nemoralis in high quality and low quality habitats. 

    All about Cepaea nemoralis.
   
    CONTROL:  Cepaea nemoralis has a very spotty distribution in Michigan and has only once been reported as a pest species by an ornamental flower grower in Lapeer County.  If C. nemoralis were to become more widespread in the state it may become necessary to control damaging populations.  Currently, no effective strategy is known to control a large pest population of C. nemoralis.  I am using a commercially manufactured molluscicide (SLUGGO®) that is intended to control pest snails and slugs in small flower and vegetable gardens.  It is not known how useful this molluscicide would be for controlling a large population of C. nemoralis in their natural environment.  My research will offer insight into the successful management of C. nemoralis.  Iron phospahte is much less toxic to wildlife than metaldehyde or carbamates and seems to be a good choice where household pets and children play.  

    PARASITOLOGICAL APPLICATIONS:  This tracking technique may also be used to better understand the spread of a disease causing organism (helminth "parasitic worm") through human populations.  Many exotic snails that are introduced to the United States harbour helminths that may pose a serious health risk to humans.  An example would be the giant African land snail, Achatina fulica, which is host to the nematode parasite, Angiostrongylus cantonensis, which in the human host can cause eosinophilic meningitis.  Understanding natural host snail dispersal may help to manage and control the spread of a potential disease causing organism.  Cepaea nemoralis does not harbour any knownfulica organisms that are a health risk to humans it is primarily an agricultural pest.  The picture to the right is Achatina fulica.


Reference:  Shigesada, N., and K. Kawasaki.  2002.  Invasion and the range expansion of species: Effects of long-distance dispersal.  Pages 350-373 in Dispersal Ecology: The 42nd Symposium of the British Ecological Society.  Edited by J.M. Bullock, R.E. Kenward, and R.S. Hails.  Blackwell Publishing.   




Other Cepaea Pictures

diode1   photo by M. Gillilland
Cepaea nemoralis fitted with a monopole or single wire transponder (note that the diode
is attached directly to the shell).   This transponder allows for the tracking of snails
with harmonic radar.


transponder photo by M. Gillilland
Cepaea nemoralis fitted with a double wire transponder (note that the diode
is between the two wires).  This design allows for tracking at much greater
distances (> 10 meter). 

diode2   photo by M. Gillilland
Several snails fitted with transponders.


x13   photo by M. Gillilland
Snail X13 recaptured using harmonic radar (note the Poison Ivy).

b1 photo by M. Gillilland
Cepaea nemoralis climbing in the grapes.


Updated 06/29/2005 by Merritt Gillilland   

MAIN PAGE