- Author: Mackenzie Patton
Eucalypt trees have become abundant in the California landscape, but so have the many invasive eucalypt pests that have arrived in California in the last couple decades.
In the fall of 2022, yet another invasive pest was added to the hoard of beetles, psyllids, and gall wasps that attack eucalypt trees. The dotted paropsine leaf beetle (Paraopsis atomaria) was found on a lemon scented gum tree (Corymbia citriodora) in Los Angeles County. It was the first report of the dotted paropsine leaf beetle in North America, and it has since become more problematic throughout Southern California. Currently the extent of the spread is unknown.
Like eucalypt trees, the dotted paropsine leaf beetle is...
- Author: Mackenzie Patton
The Invasive Pest Spotlight focuses on relevant or emerging invasive species in California. In this issue we are covering brooms, a group of invasive shrubs.
Invasive Broom facts
Brooms are upright shrubs in the legume family that typically produce small, yellow, pea-shaped flowers. Shrubs range from 3 to 10 feet tall. They produce flowers from mid spring to summer and produce seed pods in late summer. All brooms are prolific seed producers, with a single shrub producing as many as 2,000 to 3,500 pods containing up to 20,000 seeds.
While brooms are attractive plants, they grow in dense stands that outcompete many native plants. These dense stands are highly...
They may seem too tiny to do much damage to a mature, healthy tree, but invasive shothole borers (ISHB) are responsible for the deaths of tens of thousands of trees in Southern California. These beetles bore into trees and infect them with Fusarium dieback, a fungal disease that kills the trees. Many native California trees like California sycamore, valley oak, and arroyo willow can be killed when invasive shothole borers attack them.
While these pests are currently only found in Southern California, they could spread to many other parts of the state. Limiting the infestation will reduce their impact. Controlling the beetles is difficult but includes regular monitoring of trees to quickly identify sources of...
Although all cockroaches in California are considered pests, the Turkestan cockroach is of particular concern. This cockroach has become increasingly common in California's residential outdoor areas because it has faster growth and higher reproduction rates compared to other cockroaches that live outdoors. Like other cockroaches, the Turkestan cockroach is considered both a nuisance and a public health issue.
What does the Turkestan cockroach look like?
Adult Turkestan cockroaches are about 1 inch in length. Females are slightly larger than males, dark-colored, flightless, and have distinct pale stripes right below their heads on their wing buds. Males are light brown with fully developed wings....
There are several flatheaded boring beetles in California, however only a few are of particular concern. The goldspotted oak borer (GSOB), Agrilus auroguttatus, is a metallic wood-boring beetle that threatens our native trees. Since it was introduced to Southern California on contaminated firewood in the early 2000s, this pest has caused extensive damage to woodlands and native oaks.
What does the goldspotted oak borer look like?
Adult GSOB are 0.4 inch long and 0.08 inch wide with bullet-shaped bodies. They are black with an iridescent green sheen and six distinct gold spots on their back.
What damage does the goldspotted oak borer cause?