Michigan State University Invertebrate Collections



EXOTIC, INVASIVE, & PEST SNAILS AND SLUGS

OF MICHIGAN


            The following is a gallery of snails and slugs of Michigan that are not native to the State. We will add to this gallery as we accumulate more photos and as new immigrants come to our notice. The intent is to provide a series of reference photos that will help others identify some of the snails and slugs they may encounter as they explore the state of Michigan. These photos, however, are not a substitute for diagnosis by a competent professional. Therefore, we urge you to consult directly with members of the MSU Snail Lab or members of the malacology staff at the University of Michigan in Ann Arbor. If you find a snail or slug you wish to identify, always record exactly where and when you found it. We are pleased to add specimens to our collection of snails and slugs of Michigan and will include the collector’s name in our records.

            The links listed at the bottom of this page are just a few of the web sites that are concerned with exotic, invasive and pest species.


First some definitions:

         Exotic - these are organisms that are not native to the area but occasionally are found in the State- usually brought into the State by human activity. They have not, as yet, established themselves in the area.


         Invasive - these are exotic organisms that have established themselves in the State and exist as one or more populations in which individuals have successfully reproduced and appear to be spreading into new localities either by their own movement or human activity.


         Pests - these are organisms, either exotic, invasive, or native that have an economic impact on the State in that they interfere with some human activity such as agriculture and fishing, or serve as the vector for a disease causing agent, or have a detrimental effect on the survival of native species or their environment within the State.

 

 

 

 

 

 

The Giant African Land Snail, Achatina fulica, is an exotic species that is known to be a very serious pest world wide. It has not become established in Michigan but has been found in school rooms and homes as a pet. It is not lawful to own a live snail of this species!. In recent years the US Department of Agriculture has been confiscating these animals. If they were to become established, they could have very serious economic impact on Michigan's agriculture. If you have one of these snails, please kill it by boiling it or freezing it for several days. You may dispose of the animal by bringing it to the MSU Snail Lab on campus in East Lansing or giving it to your local extension agent and asking the agent to transmit it to us. If you find one for sale in a pet store or a school supply company, please let us know and we'll pass the information on to the USDA.

 

 

 

 

 

The banded wood snail or banded grove snail, Cepaea nemoralis, is an invasive species that has established populations in Gratiot, Ingham, Lapeer, Oakland and, perhaps, Wexford Counties in Michigan. A native of Europe this snail has been established in the Eastern United States for many years. It pest status is still open to some debate. It has proven to be a harvest contaminant in vinyards in upstate New York and Southern Ontario, Canada. There have been no other reported cases of this snail acting as an agricultural pest in North America. Its impact on native species has not, as yet, been evaluated.

 

 

 

The gray fieldslug, Deroceras reticulatum, is an invasive garden pest familiar to nearly everyone who plants a vegetable garden in Michigan. Although not native to North America it has been established here nearly as long as we have.

 

 

 

The heath helicellid, Xerolenta (=Helicella) obvia, has recently been found in a couple of locations in the Detroit area associated with railroad yards. This suggests that it may have arrived via freight train. It appears to be establishing itself on nearby foliage. So it is an exotic that may be becoming invasive. It has been considered an agricultural pest in Europe especially of grains.Many of its relatives are known to be serious pests in several locations, thus, there is a good chance it could become a pest in Michigan. Attempts are underway to eradicate the populations found so far.

 

These two bannana slugs, Ariolimax columbianus are exotics in Michigan having arrived in a shipment of Salal to a florist shop in Birmingham. They are native to the state ofWashington. We do not know whether they could establish themselves as invaders if released into the Michigan environment nor if they would develop pest status (they are not pests in Washington).

 

 

 

Helix aspersa (now called Cantareus aspersus) the common browngarden snail is a notorious pest in California and now world wide. Not yet established in Michigan it is easily introduced and is not legal to possess. If you find one in Michigan please notify us immediately

photo courtesy of Brian Sullivan USDA, APHIS

 

 

Hygromia cintella, an exotic with a serious pest potential given its history in other locations small population found in Wayne County appears to have been erradicated. However, this snail may easily be accidently reintroduced. photos courtesy of Brian Sullivan, USDA, APHIS

 

Monacha cartusiana an exotic with serious pest potential, two populations found in the Detroit area are currently under treatment. photo courtesy of Brian Sullivan USDA, APHIS

Candidula intersecta another exotic that has been a serious pest elsewhere a population found in Wayne County is currently under treatment. A potential harvest contaminant. photo courtesy of Brian Sullivan, USAD, APHIS

 

 

 

Helix pomatia, the escargot snail introduced in Jackson County in the 1930's has established a population, i.e. has become invasive but has not spread very widely. This particular individual, however, was recently found in Ingham County. photo by Barb Brevick

 

 

Other snails or slugs not yet pictured:. Arion subfuscus, Arion fasciatus, invasive slugs well established in hardwood forests across the state. Usually not agricultural pests, they may be having a detrimental effect on native species of slug.

 

links:

U.S. Government invasive species site

 

MSU Landis Lab

 

Garlic mustard site

 

invasive marine invertebrates

 

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