Meet the two invasive beetles on top of the unwanted critters list in Southern California.

beetles

What are their names?

The Polyphagous Shot Hole Borer and the Kuroshio Shot Hole Borer are the top two invasive beetles in California.

For a list of all invasive species in California, click Here

Why are they called Cryptic Beetles?

Entomologists, scientists who study insects, have called Kuroshio and Polyphagous beetles cryptic because they look physically identical, although they are genetically different.

For detailed description of the physical and genetic features of the beatles, click Here

What do they look like?

The beetle is the size of a sesame seed. It penetrates ½ to 1 ½ inches into the wood. There are often many exit holes on an infested tree.

For detailed description of the physical and genetic features of the beatles, click Here

Why are they invasive?

The beetle can be traced to two different places: 1)The Kuroshio beetle was hiding in wood packing materials and equipment that were imported from Vietnam and Taiwan. 2) The Polyphagous beetle was found in avocados that came from Israel. The beetle caused so much damage because it thrives in warmer temperatures just as are available in Southern California.

For a history of the invasion, click Here

What harm do these beetles do?

The invasive beetle bores into trees and attracts fungus which it eats. The fungus disrupts the water and nutrients flow and the trees die over time branch by branch.

For detailed description of the damage caused by the invasive beetles in Southern California, click Here

Where did the beetles invade in Southern California?

The beetle can live in 64 different types of trees in 6 Orange County cities. The beetle seems to prefer riverside trees such as sycamores, cottonwoods and willows. Over a million trees was infested by 2019.

For an exhaustive list of affected trees, clickHere

Here is a map that shows infestated regions by type of beetle:

infested regions

Read more about California's plan to cure or suppress diseases caused by the Shot Hole Borer BeatlesHere

Here is a list of trees that are susceptible to Polyphagous Beetles:

trees susceptible to polyphagous

Read more about management plansHere

Here is a list of trees that are susceptible to Kuroshio Beetle:

trees susceptible to kuroshio trees

Read more about management plansHere

Here is a picture of an area that was devestated by the invasive beetles:

an area that faced tree removal after infestation

Read more about tree removalHere