Spring is finally here, but unfortunately so are the pests!
While doing your spring cleaning or staying indoors due to our recent rain, you may have noticed some insects and spiders have moved in with you. Many pests are emerging from their winter rest, and taking cover from the cool, wet weather.
If you've found tiny brown, white, and black patterned beetles on windowsills, curtains, or walls near entryways, they may be carpet beetles. Adult beetles are about 1/10 inch and feed on pollen and nectar from flowers like crape myrtle and spirea. They can be brought indoors on cut flowers or they may fly in from nearby plants outside. A few adult beetles inside your home are typically not a problem. However, be on the lookout for their larvae or signs of their damage. Carpet beetle larvae feed on natural fibers such as wool, silk, leather, fur, and pet hair. They can damage rugs and carpets, yarn, clothing, and leather book bindings. Larvae will not feed on synthetic fibers like polyester. You can reduce sources of food for larvae by cleaning up lint, hair, dead insects, or debris. Adults can be relocated to the outdoors, but larvae are more difficult to control. See Pest Notes: Carpet Beetles for management strategies.
Spiders often end up inside while looking for food and if the right conditions are present–dark, dusty, hidden areas–they may stay a while. Some people may not mind the occasional spider, as they feed on other pests like flies, moths, and beetles. It is uncommon for most California spiders to bite you, contrary to what many people think. This includes the brown recluse spider, which does not exist in California. To identify the various spiders you might come across, see the Pest Notes: Spiders.
There are many other household pests you might encounter now and throughout the year. Fortunately, UC IPM has tons of great information on what they are and how to control them! See Pests of homes, structures, people, and pets for more information, or watch UC IPM's webinar recording on Springtime Household Pests.
Spring into the following free webinars from the UC IPM Urban & Community Program! Held every third Thursday from 12:00-1:00pm PDT, these informative webinars will help you identify, prevent, and control pests in and around the home, garden, and landscape!
April 20, 2023: Aphids, Scales, and Mealybugs, Oh My!
Insects such as aphids, certain scales, mealybugs, and others can produce a sticky substance called honeydew that can create a big mess around gardens and landscapes. Learn how to identify, prevent, and control these honeydew-producing insects and their damage to plants. This presentation will be given by Karey Windbiel-Rojas, UC IPM Associate Director for Urban & Community IPM/Area IPM Advisor. Register for this webinar.
May 18, 2023: Birds: Friends or Foes?
Birds are sometimes considered pests around homes, buildings, and in gardens, but they can also help to control other pests. This webinar will cover pest bird biology, identification, monitoring, and common types of damage; in addition to predatory birds and ways to enhance their control of pests. This presentation will be given by Breanna Martinico, Human-Wildlife Interactions Advisor, Napa, Lake, and Solano counties. Register for this webinar.
June 15, 2023: Summertime Household Pests
This webinar will cover identification, prevention, and management of common household pests that can be a problem in the summer months. Dr. Andrew Sutherland, Area Urban IPM Advisor for the San Francisco Bay Area, will present the webinar. Register for this webinar.
July 20, 2023: Natural Enemies & Beneficial Bugs: What are they?
While some insects can be damaging pests, many others are actually useful and keep pest species in check by parasitizing them or preying on them. These beneficial bugs are known as natural enemies and are vital to help keep pests from getting out of control. In this webinar, learn about natural enemies, how to identify them, and how they can help you out in your home and garden. This presentation will be given by Eric Middleton, Area IPM Advisor for San Diego county. Register for this webinar.
Can't make a webinar? Don't worry, all presentations are recorded and posted on the UC IPM YouTube channel! More webinars will be announced in the late summer. Follow us on social media @ucipmurban for the latest IPM content and news.
Webinars from the IPM Institute of North America
From April 10-14, Midwest Grows Green and Green Shield Certified will host Green Shield Week, a series of webinars discussing sustainable landscaping and pest management practices, strategies and policies. The webinars include:
- Monday, April 10th – Barry Draycott from Tech Terra Environmental discusses how to protect our water resources while maintaining a healthy and resilient lawn. Register for free at bit.ly/GreenLawns23.
- Tuesday, April 11th – Bradley Herrick from the University of Wisconsin Madison Arboretum focuses on best management practices, control methods and latest research of jumping worms. Register for $10 at bit.ly/InvasiveJumpingWormsWebinar.
- Thursday, April 13th– Dr. Doug Richmond from Purdue University's Soil Insect Ecology Laboratory presents a systems approach for integrating cultural, biological and low impact chemical tools to reduce the ecological footprint of managing turf pests. Register for $10 at bit.ly/SustainablePest23.
Termite Awareness Week is a campaign created by the National Pest Management Association to call attention to the damage termites can cause to structures and to make sure residents and professional pest managers understand how to prevent and deal with termite infestations.
Did you know?
- Of the 23 species of termites in California, only 3 are considered pests. The three pest species are dampwood, drywood, and subterranean termites.
- Subterranean termites are the most common in California. They live in underground nests and can be found infesting wood that is in contact with the soil, including structural lumber in homes and landscapes, as well as fallen trees, tree stumps, or other dead wood.
- If you come across groups of insects on the ground that appear to be winged termites, they may actually be winged ants. For help distinguishing ants from termites, see the UC IPM Ant Key.
- Dampwood termites are larger than subterranean and drywood termites. They are most common in cool, humid areas along the coast and are attracted to lights at dark.
- Termites play a very important role in California forests, woodlands and deserts by helping to break down woody organic matter which helps return nutrients to the soil. And contrary to popular belief, termites rarely injure or kill healthy trees.
If you suspect you might have a termite infestation in your home, contact a professional. Do-it-yourself insecticide treatments are not recommended and are often not effective. To learn more about termites and available management strategies for professionals, read the Pest Notes: Subterranean and Other Termites and the Pest Notes: Drywood Termites.
- Author: Randall Oliver
Reposted from UC ANR news
Early detection increases the chances of eradicating pests
Trees provide shade to keep us cool, produce oxygen for us to breathe and calm our nerves. Numerous studies have demonstrated that even brief contact with trees and green spaces can provide significant human health benefits such as reductions in blood pressure and stress-related hormones. Trees also reduce noise and visual pollution, help manage storm water runoff, reduce erosion and provide habitat for birds and wildlife. Trees naturally capture carbon, helping to offset the forces of climate change. They also increase the value of our properties and communities. In short, trees are essential to our well-being.
Unfortunately, invasive pests pose an ongoing threat to California's forests in both urban and wildland settings. Invasive insects such as goldspotted oak borer and invasive shothole borers have killed hundreds of thousands of trees in Southern California and are continuing to spread. Meanwhile, other pests and diseases such as Mediterranean oak borer and sudden oak death are killing trees in Northern California.
While the situation may sound dire, it is not hopeless. Of course, the best way to stop invasive pests is to prevent them from entering the state, as the California Department of Food and Agriculture has done on many occasions. For example, several months ago, CDFA border inspectors seized a load of firewood containing spotted lanternfly eggs (a pest that is causing extensive damage on the East Coast). When pests do sneak in, the next defense is to catch them early before they become established. Finally, even if pests do become established, they can be managed if not completely eradicated.
A few examples may help to illustrate why invasive tree pests deserve action, but not panic.
Red striped palm weevil eradicated in Laguna Beach
When red striped palm weevil, a highly destructive palm pest native to Indonesia, was discovered in Laguna Beach in October 2010, a working group was quickly formed to develop a management plan. The small but diverse group included international palm weevil experts, research scientists from University of California Riverside, CDFA and U.S. Department of Agriculture, UC Cooperative Extension personnel from San Diego, Orange and Los Angeles counties and county entomologists from the agricultural commissioner's offices in Orange and San Diego counties.
The resulting response included a pheromone-based trapping program, public advisory and targeted insecticide treatments. Within two years, additional trapping and inspections could not find any signs of continued infestations. Early detection was key to the success: the infestation in Laguna Beach was identified early, so the weevil population was still relatively small. In addition, Laguna Beach is geographically isolated, the local climate is much cooler than the weevil's place of origin, and the eradication effort was well funded by state and federal agencies. Eliminating invasive pests where such conditions are not present may prove more difficult.
Invasive shothole borers attack Disneyland
The Disneyland Resort in Anaheim contains 16,000 trees and over 680 different tree species. When park officials identified an infestation by invasive shothole borers in 2016, their initial attempts at vanquishing the insects with pesticides produced mixed results. Then, they consulted with experts from UC Riverside and UC Cooperative Extension and together designed and followed an integrated pest management program that included monthly ground surveys, a trapping program that helped to detect infestation hot spots and find and remove the source of beetles, and occasional pesticide treatments on selected trees. The park went from a large number of beetles in 2017 to very low levels today. There are still some beetles, but resulting damage is extremely low, and although monitoring programs continue, the park's landscape team has been able to turn its focus elsewhere.
Goldspotted oak borer spotted in Weir Canyon
When goldspotted oak borer was confirmed in Orange County's Weir Canyon in 2014, a team from Irvine Ranch Conservancy, the organization that manages the area on behalf of Orange County Parks, sprang into action. UC Cooperative Extension and the US Forest Service assisted IRC in developing a management program, and over the ensuing years, IRC has actively collaborated with OC Parks, The Nature Conservancy, OC Fire Authority, and CAL FIRE to control the existing infestation and stop its spread. IRC has surveyed the oaks in the area yearly to monitor the infestation and guide each year's management actions.
To reduce the spread of the infestation, IRC removed more than 100 severely infested oaks in the first few years of management (no severely infested oaks have been found in the last few years of surveys). Additionally, more than 3,000 tree trunks have been sprayed annually in the late spring to kill emerging adult beetles and newly hatched offspring.
In the most recent survey of the oaks in Weir Canyon, the IRC team found only 12 trees with new exit holes, and most of those had just one to two exit holes per tree, which is an extremely low number. With the situation well under control, IRC is now considering modifying its annual spraying program and adapting other less aggressive treatment options. Finally, IRC has been actively planting acorns to mitigate losses due to the removals as well as the Canyon 2 Fire of 2016.
As these brief examples demonstrate, insect pest infestations can be managed or even eradicated if caught early enough. Early detection not only increases the chances of success, but also minimizes the cost of pest management efforts.
What you can do to prevent infestation
While management actions will vary depending on the insect or disease, species of tree and location, there are a few steps that will lead to greater success in fighting tree pests and diseases.
- Keep your trees healthy. Proper irrigation and maintenance go a long way toward keeping trees strong and resistant to pests and diseases.
- Check your trees early and often for signs and symptoms of tree pests and diseases. These may include entry/exit holes, staining, gumming, sugary build-ups, sawdust-like excretions, and branch or canopy dieback. Use available tools like the UC IPM website to determine probable causes of the problems.
- Talk with experts (arborists, pest control advisers, researchers and advisors from the University of California and other institutions), and report pest findings to your county Agricultural Commissioner.
- Evaluate the extent of tree damage and determine a management plan. Remove severely infested branches and trees that may be a source of insect pests that can attack other trees.
- Properly manage infested wood and green waste. Chip wood and other plant materials as small as possible. Solarization or composting can further increase the effectiveness of chipping. It is generally best to keep those materials close to where they originated, but if you absolutely need to move them, first make sure the facility where they will be sent is equipped to process them. Always tightly cover materials while in transit. If working with a tree care professional, insist that proper disposal is part of the job requirements.
- Many invasive tree pests can survive in down wood for long periods. When buying or collecting firewood, always obtain it as close as possible to where you are going to burn it and leave leftover firewood in place.
- Author: Karey Windbiel-Rojas
- Editor: Lauren Fordyce
Invasive pest species threaten California's natural environment and can have an impact on public health. Help spread the word about these invasive species and how to limit their introduction, spread, and harm. Learn to recognize these pests and distinguish them from look-alikes. If you suspect you have found any of these species, contact your local County Agricultural Commissioner or report it to the CDFA Report a Pest Hotline.
Emerald Ash Borer
The emerald ash borer (or EAB) is an invasive insect that has been found for years in numerous states across the country, but until recently had not been found on the West Coast. In June 2022, EAB was detected in Oregon. This insect feeds on all species of ash trees and has the potential to devastate whole communities of trees.
See the California Department of Food and Agriculture website for information about its biology and national distribution.
Spotted Lanternfly
In California, we've been on the lookout for the spotted lanternfly (SLF) for several years. In July 2022, a truck carrying firewood into California from New Jersey (silly, I know!) was inspected at a CDFA Border Inspection Station in Truckee and the wood was found to be carrying egg masses of SLF. The wood was destroyed but this is a significant detection.
Understand the danger of moving firewood from place to place within the state and especially across state borders. Firewood can harbor many types of invasive pests including SLF but also invasive shothole borers, gold-spotted oak borers, and other very hard to see invasive insects AND diseases.
Jumping worm/crazy worm
The invasive jumping worm (Amynthas agrestis) has many common names: Alabama jumpers, Jersey wrigglers, wood eel, crazy worms, snake worms, Asian jumping worm, and crazy snake worms. The jumping worm has been found in Napa and Sonoma Counties. It is similar-looking to the common earthworm but thrashes wildly and is said to jump as much as 1 foot off the ground.
Like other earthworms, jumping worms eat fallen leaves and other natural material on the ground. However, these worms are voracious eaters. They eat so much of the soil “litter” layer that they nearly clear the top soil of all life. Many plants can't grow or spread without this layer of leaf litter, plus this disrupts the ecosystem of the leaf litter.
Read more about this worm in this article by Oregon State University. UC IPM is compiling information about the worm and where it has been found in California and will publish and announce this information once finished.
Stay Informed
There are many other invasive species in California being monitored for state agencies and many others receiving management efforts. Be sure you are subscribed to the UC IPM Home & Garden Pest Newsletter and social media platforms (@ucipmurban) to ensure you are receiving timely updates and news.
Other useful resources for these invasive pests and many others:
UC IPM Invasive and Exotic Pests web page
Center for Invasive Species Research at UC Riverside
Urban & Community IPM webinars https://ucanr.edu/sites/ucipm-community-webinars/
CDFA target pest web page https://www.cdfa.ca.gov/plant/PDEP/target_pests.html
