This week, we put the spotlight on invasive species and how these non-native plants, animals, and pathogens damage California's economy and environment.

You Can Make a Difference

Shot hole borers and the diseases they carry, and Asian citrus psyllid and huanglongbing disease are serious invasive pests of concern. Do your part to help prevent their spread. If you go camping this summer, don't move firewood from your home to the campground. For backyard citrus growers, find out if you are in a quarantine zone for Asian citruspsyllid. You can make a difference. Read the posts above to find out...

Shot hole borers are tiny insects the size of a sesame seed that don't look particularly harmful, but don't let their diminutive size fool you. Two of these borers are invasive—the polyphagous shot hole borer and the Kuroshio shot hole borer. They carry pathogens and are spreading them throughout southern California. Together, the borers and the fungi are a deadly combination that are killing many trees. Trees affected include avocado, sycamore, white alder, box elder, cottonwood, and willow.

The two shot hole borers are nearly identical in appearance, and both have a symbiotic relationship with several pathogenic fungi. The female borers lay eggs which introduces fungi into trees. The fungi grow and provide food for...

It may surprise you to learn that California is home to invasive wild pigs, also called feral hogs or wild boars. Wild pigs can be a major nuisance for farmers, ranchers, and others who live in more rural areas or near wildlands. They will invade fields and eat crops, disturb plantings by rooting through the soil, and defecate in fields leaving behind bacteria and parasites.

How did these pigs become wild?

As is the case with many introduced invasive species, wild pigs were an accidental creation. Spanish missionaries brought domestic pigs to California in 1769 for consumption, but after being released for foraging and not recaptured, they escaped domestication and became feral (wild). These feral pigs...

As part of our coverage of California Invasive Species Action Week, today we focus on a pair of invasive species that “work” together: an insect called the Asian citrus psyllid and the plant disease it can spread, huanglongbing.

Our long-time readers will know that we write about these pests quite a bit. That's because this pest pair has the potential of causing profound economic harm to the California citrus industry. So please read on and found out what you can do to help.

The Basics

The Asian citrus psyllid (ACP) is a very small flying insect that feeds on citrus plants...