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Please Document Invasive Species Under Your Garden Pots!

Updated: Dec 12, 2022

Land planarians, snails, slugs, insects, arachnids, worms, oh my!

A guest post by Robin Agarwal

This year, for the first time, Bioblitz Club is participating in Invasive Species Action Week, organized by the California Department of Fish and Wildlife. The goal is “to increase public awareness of invasive species issues and promote public participation in the fight against California's invasive species and their impacts on our natural resources,” according to Dr. Elizabeth Brusati, Senior Environmental Scientist (Specialist) for the CDFW’s Invasive Species Program.

Isopod Iridescent (Virus Invertebrate iridescent virus 31): this is one of the organisms you might find while looking under potted plants. Not too many ways to observe viruses on iNat, but this is one! Perhaps because land isopods congregate closely together under pots, there appears to be a higher likelihood of seeing infected isopods in this setting. This particular virus causes isopods to turn a striking violet-blue color. Photo: Robin Agarwal.

Get involved! Between Saturday, June 4 and Sunday, June 12, 2022, Bioblitz Club members, friends and families are encouraged to photo-document the worldwide diversity of life lurking underneath your plant pots and other garden containers. Urban or rural, native and non-native species are welcome. No garden pots? No problem! Visit your local plant nursery, greenhouse or public garden!

Once you’ve taken a bunch of photos, upload them to’s Pot Fouling Project. In order to add your observation to the project, you would need to join the project first, and then add your observations manually.

This project will help scientists track non-native species in your area, so nice job.

You may even spot a first record of an invasive species! In only a few months, The Pot Fouling Project has turned up several first county records (invasive snails), a SF Bay area first record (European Gazelle Beetle) and an unconfirmed first state record (land planarian). You can learn more about the non-native flatworms in this Bay Nature article.

At the end of the week, we will report back with a summary of our stats.

Thanks for looking under those pots!

Scroll down for some interesting findings from the Pot Fouling Project:

Blue Garden Flatworm (Caenoplana coerulea): Native to Australia and now well established in California, Blue Garden Flatworms are one of over a dozen species of introduced land planarians found in California. Photo: Robin Agarwal.

Shovel-headed Garden Worm (Bipalium kewense): the Shovel-headed Garden Worm is the most common, and most distinctive-looking, introduced land planarian in the SF Bay Area. It can grow up to 20 cm long, and produces a neurotoxin in its mucus to subdue its prey. Photo: Robin Agarwal.

Southern Flatcoil (Polygyra cereolus): now with first records in two Bay Area counties, Southern Flatcoil snails were first reported in the SF Bay Area via The Pot Fouling Project. Photo: Robin Agarwal.

European Gazelle Beetle (Nebria brevicollis): How to make a beetle scientist really happy. Dave Kavanaugh of the California Academy of Sciences identified citizen scientist observations of an invasive European beetle he’s been looking for in the SF Bay Area for 20 years. Photo: Robin Agarwal.

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