Texas Invasive Species InstituteCornu aspersum
Brown Garden Snail
Synonyms: Cantareus aspersus, Helix aspersa
Class: Gastropoda
Order: Stylommatophora
Family: Helicidae
Photographer: Bill Frank Photographer: Division of Plant Industry
Source: http://entnemdept.ufl.edu/creatures/misc/gastro/brown_garden_snail.htm
Description
The brown garden snail is about 1 inch in diameter with a snail that is 25-40mm wide with 4 to 5 whorls. and has a distinct brown and grey color pattern on the shell. Cornu aspersum is a terrestrial air-breathing snail that is edible. In Britain brown garden snail farming is currently a booming cottage industry. Likewise, this snail has been used for centuries in traditional medicine to treat sore throats. Additionally, this species is an agricultural and garden pest that seems to have a preference for citrus trees and fruits. Brown garden snails exhibit a very strong homing ability that causes them to aggregate in large numbers (pictured above on the right), making them difficult to control.
Ecological Threat: With the brown garden snail having a preference for citrus trees and the ability to aggregate on plants, it is a very large threat to the agricultural community. The brown garden snail has also been observed to destroy vegetable crops, garden flowers and grain plants. Since it has a relatively long life cycle and high reproductive rate it can quickly infest citrus groves and fields of grains, causing harm to the plants, farmers and the local economy.
Biology: Garden snails are hermaphrodites, meaning that one individual possesses both male and female reproductive organs; although they are able to self-fertilize, most snails mate with another snail. Reproduction takes place in early summer, and begins with pairing and courtship. The snails separate, and the sperm is stored internally until the eggs are ripe. After the eggs have been fertilized, the snails dig pits in the soil in which to lay the eggs. Hatchlings have translucent, delicate shells. The hatchlings can take 1 to 2 years to reach maturity.
History: This snail was introduced to many parts of the world intentionally as a food delicacy, accidentally by the movement of plants, and by hobbyists who collect snails. Additionally, it was introduced to California in the 1850s as a source of escargot. It has adapted well to California and is very troublesome as a pest of crops and ornamentals. It has now spread to the states on the Atlantic coast and Gulf of Mexico.
U.S. Habitat: Occurs in in many zones that have climates differing from the original Mediterranean climate in which it first occurred. Anywhere from arid to humid environments and can be found as far North in America as Nova Scotia.
Distribution
Native Origin: Mediterranean, Northwest Africa, Egypt to Asia Minor and the British Isles.
U.S. Present: CA, CO, HI, ID, LA, MA, ME, MI, NM, NY, PA, UT, SC, TX, VA and WA
Management
Management of the brown garden snail is a four-step process that involves pruning tree skirts ; banding tree trunks with copper foil or a basic copper sulfate slurry; putting out poison (metaldehyde) bait to reduce their populations; and making releases of the predatory decollate snail, Rumina decollata. However, this is not without problems, as the decollate snail is just as likely to attack and devour other species that may be important to native ecosystems. At least the first 3 steps can help save trees and other plants the brown garden snail could potentially destroy.
Remove anything snails may hide under: boards, bags, brush and debris. During the night, place a board on the ground near damaged plants. Elevate the board with four stones placed under the corners. The snails will take shelter under the board in the morning and can be removed and then destroyed then by dropping into a jar filled with water and a little rubbing alcohol. Some birds, especially ducks, will feed on these snails.
Due to the brown garden snail, various states in the United States have quarantine restrictions concerning plant materials brought in from other states. States with quarantine regulations include Arizona, California, Louisiana, Mississippi, Oregon, South Carolina, Texas and Washington. However, other states may also have quarantines. Check with each state's Department of Agriculture to be sure before shipping or taking potentially infested materials to other states.
References
Bradley LK. 1999. Snails and slugs in the low desert. University of Arizona Cooperative Extension.
Gunn D. 1924. The brown and grey snails: Two destructive garden pests. Journal of the Department of Agriculture (Union of South Africa) Reprint No. 42: 3-10.
Internet References
http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/genustaxon?id=2793
http://www.molluscs.at/gastropoda/terrestrial.html?/gastropoda/terrestrial/otala.html
http://www.ipm.ucdavis.edu/PMG/r107500111.html
