A Desperate Mission to Eradicate the Extremely Invasive New Zealand Mud Snail

This past sunday, I embarked on a desperate mission to eradicate the extremely invasive New Zealand Mud Snail.

According to the Center for Invasive Species Research in Riverside, California, the color of the snail shell is variable, and can range from gray and dark brown to light brown. The snail is usually 4-6 mm in length in areas that have been invaded, but snails can grow to almost twice this size, up to 12 mm, in New Zealand where populations are much lower. New Zealand mud snail is a nocturnal grazer that feeds on plant and animal detritus, algae, and diatoms. Invasive populations have an unusual mode of reproduction. New Zealand mud snails can reproduce asexually and female snails are born with developing embryos inside them. Consequently, all populations consist of genetically identical clones. In New Zealand, native mud snail populations consist of sexually reproducing populations (the males make up less than 5% of the populations) and asexually reproducing females. Each snail can produce around 230 offspring a year, and reproduction typically occurs during the spring and summer.

Snails can live for 24 hrs without water, and for up to 50 days on damp surfaces. The snail is . . . tolerant of estuarine conditions and can live at depths of up to 45 m on solid and silty substrates. Once introduced into a new area, New Zealand mud snails can reach densities exceeding 500,000 per square meter. (http://cisr.ucr.edu).

Upon my discovery as to what the snails in my bin were, I set to figuring out how to get rid of them. After discussing things on a couple of different forums, I decided that the only way would be to get rid of all of my bedding, wash my bin with the hottest water I could stand, and rinse off my worms and cocoons the best that I could. Then I put them in fresh bedding and left them alone for several days. The best way to kill the snails is to put them in salt water, so I took all of my contaminated bedding and dumped it in salt water and then disposed of it.

Today I checked my worms to make sure that I did have a few at least, that survived the stress. They were happily munching away on the rotting food and bedding I had provided for them. Hopefully there are no remnants left of the snails so I won't have to put my worms through that again.