Invasive Species

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The letters "CISAW" animated as invasive species organisms.
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Protect California from Invasive Species

June 5, 2025
Invasive species. What does that mean? Invasive species are non-native pests that harm California’s natural areas, public health, and economy. To raise awareness about these pests, UC IPM joins other state agencies to promote the annual California Invasive Species Action Week (CISAW), which goes from June 7…
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Pests

Learn about garden pests, including insects like aphids and earwigs, and wildlife like gophers and deer. Learn how to manage them.
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Cross section of a tree trunk that has trellis-like tunnels throughout. The tunnels are dark stained and go deep into the wood.
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Mediterranean Oak Borer: Questions & Answers

May 28, 2025
The Mediterranean Oak Borer (MOB) is an invasive ambrosia beetle that infests several species of white oaks in California: valley oak, blue oak, and Oregon oak. The beetle is spreading rapidly in Northern California counties and there is considerable potential for the beetle's range to expand as they…
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An adult emerald ash borer beetle on a leaf damaged by its feeding.
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Emerald Ash Borer Awareness Week 2025

May 15, 2025
By Lindsey Hack
Tiny but destructive, the emerald ash borer (EAB) is an invasive beetle that has killed millions of ash trees across North America. In some cases, infested regions have lost nearly 100% of their ash trees to this pest. Though EAB has not yet been found in California, it was detected on the West Coast for the…
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Brown shield-shaped stink bug with brown mottling on the body on a green leaf.
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2025 Invasive Species Mini-Series

Brought to you by UC IPMs' Urban and Community TeamInvasive species are reshaping California’s natural and urban landscapes. This mini-series explores the many fronts of invasion, from harmful garden pests and aquatic hitchhikers to destructive tree pests, invasive weeds, and the policies that guide…
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Tree-of-heaven growing over a sidewealk in a neighborhood.
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Invasive Pest Spotlight: Tree-of-Heaven

May 7, 2025
By Cherie Shook
Tree-of-heaven, Ailanthus altissima, was originally from China and became a popular landscape shade tree in the 1800’s. However, its rapid growth, aggressive spread, and native habitat disruption have made it a global problem. Reproducing rapidly through dense root suckers and wind dispersal of its “winged”…
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A smiling UC Master Gardener volunteer in an orange hat and green apron stands with arms raised in a garden setting, surrounded by people and plants.
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Top 5 Ways Gardeners Can Help Stop Invasive Species

April 25, 2025
By Lauren L Snowden
Did you know that your backyard, balcony, or community plot is more than just a space for flowers and veggies? It's also a frontline defense against invasive species! As gardeners, we’re uniquely positioned to protect local ecosystems, and the good news is—it doesn’t take a lot to make a big difference.Here…
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Bermuda buttercup infesting a bed of landscaped plants.
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Spring is in the Air, and Oxalis is Everywhere

April 17, 2025
By Lindsey Hack
Bermuda buttercup (Oxalis pes-caprae), also called buttercup oxalis or sourgrass, might be a familiar sight in winter and spring, particularly to those who live in coastal regions or the Sacramento Valley. Some people enjoy seeing this plant’s cheerful yellow flowers pop up in their spring gardens, but for…
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