- Author: Anne Schellman
Beetles are the most plentiful of all insects on the planet, so it's understandable to get a few of them confused. Let's compare photos and other details about each of these beetles, and also mention the green June beetle, a beetle that is commonly mistaken for the Japanese beetle.
Japanese Beetles
Japanese beetles do not have an established population in California. The California Department of Food and Agriculture* (CDFA) maintains traps for detecting this pest throughout the state. When Japanese beetles are found in California, they are targeted for eradication (complete elimination). Read more about this invasive species on the UC IPM website at https://ipm.ucanr.edu/Invasive-and-Exotic-Pests/Japanese-Beetle/
Green Fruit Beetles
Green fruit beetles are a dull green color and much larger than Japanese beetles. You may notice them in late spring and summer as they zoom around your garden. Fortunately, they are rarely a pest. https://ipm.ucanr.edu/PMG/GARDEN/FRUIT/PESTS/grfruitbeetle.html
Rose Chafer Beetles
The rose chafer beetle resembles the hoplia beetle, however, this pest is not found in California. You can read more about these beetles on this informational page from University of Minnesota https://extension.umn.edu/yard-and-garden-insects/rose-chafers
Hoplia Beetles
Hoplia beetles are small, brown, and their undersides look like they've been dusted in gold. If you hold one in your hand, they will “play dead” and not move, making it easy to examine them.
You can read more details about managing hoplia beetles in the UC IPM Pest Notes: Hoplia Beetles.
*it's important that we help prevent invasive pests from taking hold in our communities and threatening agricultural crops. You can help by saying "yes" when trappers from the Agricultural Commissioner's Office ask if they can place traps in your landscape tree.
Anne Schellman is the Coordinator for the UC Cooperative Extension Master Gardener Program.
This article was originally published on May 8, 2023.
/h3>/h3>/h3>/h3>- Author: Karey Windbiel-Rojas
Originally posted August 26, 2016; edited July 10, 2018
Have you seen big green beetles in your California yard or garden? Or beetles feeding on your roses or other plants? There are many kinds of beetles commonly found in our landscapes, but the Japanese beetle is not one of them.
Japanese Beetles
Many people think they've seen the Japanese beetle, a small scarab beetle with metallic green wings with white spots on the margins. However, Japanese beetles are generally not found in California.
Green Fruit Beetles
Green fruit beetles are large beetles commonly found during spring and summer in California. While green fruit beetles are much larger than Japanese beetles and have different markings, these two beetles are frequently mistaken for each other. Adult green fruit beetles feed on ripe and overripe stone fruits, but damage is typically negligible so no control is necessary.
Beetles
Hoplia beetles are small, reddish-brown oval beetles that feed primarily on roses. They occur between March and May in California and tend to prefer feeding on light colored rose petals. For more information about hoplia beetles, see the Pest Notes: Hoplia Beetles.
Masked chafer grubs feed on the roots of turfgrass. Damage appears in late summer or fall as irregular patches of brown, dying grass.
When full grown, white grubs are about 1-inch-long, much bigger than some other lawn beetles. Read more about masked chafers and other lawn pests at http://ipm.ucanr.edu/PMG/PESTNOTES/pn7476.html
Be a Part of the Solution
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Hoplia beetle adults are small, reddish-brown scarab beetles that are often found resting inside a blossom. If you hold one in your hand, you'll notice that most of the body is a beautiful, iridescent silvery green color in the sunlight.
These beetles may also occasionally be found feeding on other plants with light-colored petals.
Some people believe they have the rose chafer or Japanese beetle in their landscape, however neither of these pests have populations in California.
Hoplia beetles are best managed using nonchemical controls such as handpicking. For more information on identification and management, see the UC IPM Pest Note: Hoplia Beetles.
- Author: Andrew Mason Sutherland
Insect pests, though actually quite rare in well-managed lawns and turf, can sometimes jeopardize a flawless appearance, potentially sending people running to their local nursery or garden center for help.
The recently revised UC IPM Pest Note: Lawn Insects can prepare you with answers to keep lawns pest-free and BBQ ready this summer. This resource contains a wealth of information about lawn insect prevention and management, including coverage of most insecticides for use in residential lawns and an updated treatment table with many new IPM-compatible active ingredients.
Early Prevention and Monitoring
Often times, damage due to lawn insect pests only becomes apparent during late summer and fall, when low soil moisture and heat stress take a visible toll on areas with damaged roots or tattered blades. Unfortunately, it is difficult, or even impossible, to reverse the damage at this point since pests may already be gone or dormant and because grasses are no longer vigorously growing. For example, the larvae of masked chafers (the most common and most damaging of the ‘white grub' species, having only one generation per year in California (Figure 1)) have largely stopped eating roots and stopped growing in size when the damage they cause is most observable (autumn). The most effective treatments should have been made in June or July, when grubs were small and damage had not yet appeared. Considering such delays in damage, remember that prevention and monitoring are the most important management tactics for lawn pests and that you may have to plan ahead for the future if your goal is a pest-free lawn.
In fact, pest management for lawns and turf areas should begin during design and installation of the site, with species selection, proper grading and drainage, appropriate irrigation systems, and a maintenance plan. Choosing the appropriate turf species for the site by considering regional climate and water availability is the single best way to reduce overall stress and to ensure longevity and resiliency of the grasses planted.
UC IPM's online resources such as the UC Guide to Healthy Lawns can help you choose appropriate turf species based on tolerance to key stressors such as temperature, salinity, drought, and foot traffic.
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