- Author: Help Desk Team
Earwigs are one of the most common pests in our gardens. There is a lot to learn about them besides knowing how to prevent the damage they cause.
Fun facts about earwigs:
- Their name probably comes from myths surrounding these insects:
- They sometimes enter peoples' ears when they are sleeping and they sometimes burrow into the brain
- The forceps appendages at their rear ends look like tools to puncture ears for earrings
- The expanded wings of earwigs have the shape of human ears
- The common and abundant earwigs in our gardens weren't even in California 100 years ago.
- Roald Dahl, author of children's books, has a character in George's Marvelous Medicine that urges the grandson to eat a ‘big fat earwig' and tells him how to do it so it wouldn't grab his tongue with the ‘sharp nippers on its back end.
- Roald Dahl also mentions earwigs in James and the Giant Peach where the characters find an earwig inside the giant peach.
- Under their hard, shiny wing covers, they have remarkably large and complex flight wings that spring from folded to flight without muscles. (These wings expand to 10 times larger than when folded.)
- Female earwigs watch over their eggs and newly hatched young, protecting them and keeping them clean until they are old enough to fend for themselves.
Did you know?
- Earwigs are important predators of aphids, mites, nematodes, and other small insects and their eggs.
- Research from Washington State University shows earwigs can be beneficial in apple and pear trees, eating pests but doing minimal damage to the crop.
- They also feed on fungi and decaying plant material.
- They are food for other animals, including birds and lizards.
Tips to control earwigs in your garden:
- Remove their hiding places. Earwigs thrive in dark and moist areas during the day, coming out to feed at night.
- Clean up debris, leaf piles, and decaying plant matter
- Trap them by placing numerous traps throughout your yard.
- Use empty tuna or cat food cans with ½ inch of vegetable oil and a smelly substance such as fish oil or bacon grease. Place these in your garden bed with the top of the can level with the soil. In the morning, dispose of the trapped earwigs.
- Roll up damp newspaper, secure with rubber bands, and place in your garden bed. Next morning, collect them and shake the earwigs into a pail of soapy water.
- Baits such as SluggoPlus can be used, but often they are not effective if the earwigs have other attractive food sources like your tasty garden.
For more information about earwigs, please visit these links:
https://ipm.ucanr.edu/PMG/PESTNOTES/pn74102.html
Ode to an Earwig https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=51351
Earwigs in California (published 1975): https://essig.berkeley.edu/documents/cis/cis20.pdf
Washington State University study: https://www.mdpi.com/2075-4450/14/12/906
Help Desk of the UC Master Gardeners of Contra Costa County (SEH)
- Author: Belinda Messenger-Sikes
During the holiday season, the only creatures you want stirring in your home are your family, friends, and pets. But as temperatures drop, and the rain returns, some pests may seek shelter indoors with you. Rats and mice can be problems all year but in the cold weather, they prefer the warmth of your home to being outdoors and you might see more in your home.
Pests invade homes for varying reasons during autumn and winter. Common outdoor species such as Argentine ants, Oriental (or Turkestan) cockroaches, sowbugs and pillbugs, springtails, and earwigs, may simply be escaping harsh conditions such as freezing temperatures or small-scale flooding. Some insects, especially true bugs (Hemiptera); such as boxelder bug, bordered plant bug, milkweed bug and other seed bugs, false chinch bug, and various stink bugs, naturally seek out dry, protected cracks and crevices to spend the winter. In the landscape, such sites may be beneath loose tree bark or deep within firewood piles, but structural gaps, cracks and crevices may be warmer, drier, and more attractive to these overwintering bugs.
It's generally easier to keep pests out before they become a problem than to try and get rid of them once they infest your home. Exclude pests by sealing up possible entry points around doors, windows, foundations, chimneys, roof joints, shingles, and vents. Install door sweeps and threshold seals to get rid of gaps under and around doors. If you have gaps around windows, you can close them with weather stripping and expanding foam or install new screens.
Clean up the landscape around your home so pests have fewer places to live and breed. Move wood chips and other organic mulches, and firewood piles away from your home's perimeter and entryways. Drain any excess moisture near structural foundations and entryways.
If you spot nuisance pests like boxelder bugs, earwigs, springtails, and centipedes indoors, they can be simply swept up, vacuumed, or taken outside. Other pests like mice and rats need to be dealt with differently.
Ideally, mice and rats should be managed before they get inside. Check the exterior of your home for signs of a mice or rat infestation including droppings, gnaw marks, feeding damage, and rub marks. For mice and rats, tight fitting lids on garbage cans and compost containers will keep these rodents from finding a food source near your home and eventually coming indoors. Thin vegetation between shrubs and buildings and trim back overhanging trees. Roof rats will use climbing vegetation to scale buildings and seek shelter. Seal any cracks or gaps into your home that are larger than 1/4 inch. Screen or block potential entrances under eaves or overlapping roof sections. Use sheet metal or 1/8-inch wire hardware cloth to keep out mice and rats since rodents can gnaw through softer material like plastic or wood.
Snap traps are the safest, most effective, and most economical way to manage rats and mice. You can place traps outside the home to catch rodents before they enter. You can also place them inside if you spot signs of them there. Be sure to use the correct-sized traps and place them in secluded areas along walls, behind objects, in dark corners, and in places where droppings have been found.
Keep pests from ruining your holiday fun by denying them food, water, and shelter in your home. For more details about specific pests and their management, see the UC IPM website https://ipm.ucanr.edu/PMG/menu.homegarden.html.
[Originally featured in the Winter 2023-2024 edition of the Home & Garden Pest Newsletter.]
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.
- Author: Kathy Keatley Garvey
She will deliver her in-person seminar at 4:10 p.m. in Room 122 of Briggs Hall.
“Growers and pest control advisors in California suspect that European earwigs (Forficula auricularia) damage young citrus fruit,” she writes in her abstract. “However, very little is known about herbivory by earwigs on citrus fruit. Our work details characteristics of herbivory by earwigs on citrus fruit and the use of sticky and pesticide barriers to manage earwigs and other citrus pests.”
Kahl, awarded her doctorate in August, focused her research on understanding the role of European earwigs in California citrus; developing a whole systems approach to manage earwigs and other citrus pests; and feeding preferences of fort-tailed bush katydids and citrus thrips on California citrus.
Kahl is now an ecological pest management specialist at Community Alliance with Family Farmers, Davis. She leads projects and extension efforts on sustainable pest management tactics.
She received an ongoing grant in 2019 from the Citrus Research Board on “Characterizing Earwig Damage to Citrus Fruits, and Damage Prevention using Trunk Barrier Treatment.” She also received a National Science Foundation Graduate Research Fellowship, awarded in 2017, and a 2018-19 Keller Pathways Fellowship (for entrepreneurship) from the University of California.
Kahl holds a bachelor's degree in biology from Whitman College, Walla Walla, and a master's degree in entomology from the University of Maryland, College Park. She studied abroad in a six-month School for International Training program in Jaipur, Rajasthan, India in 2010. Her research topic: Village dairy production in Haryana and Orissa.
This is the department's first seminar of the fall series. Many of the seminars will be virtual, said nematologist Shahid Siddique, who is coordinating the seminars. For more information,contact him at ssiddique@ucdavis.edu
(Due to website issues, no photos could be posted. See Bug Squad post for images)
- Author: Kathy Keatley Garvey
“They feed mostly at night and hide during the day,” according to the UC Statewide Integrated Pest Management Program. They hide in the bark crevices, mulch, and “protected compact plant parts such as dried, curled leaves, and under trunk wraps.”
“Earwigs feed on dead and living insects and insect eggs and on succulent plant parts, UC IPM says. "Earwig nymphs and adults will climb trees and feed on flower buds, leaves, and fruit of trees during the spring flush months (March through May). Nymphs tend to feed on plant material more than adults...Earwigs can be very problematic on young trees with trunk wraps or cardboard guards, in which they reside. They climb the trees and feed on the new leaves. Large numbers of earwigs can defoliate trees.”
Enter ecological pest management specialist Hanna Kahl, who recently received her doctorate in entomology from UC Davis, studying with UC Davis distinguished professor Jay Rosenheim. She'll present her exit seminar on “Herbivory of Citrus Fruit by European Earwigs in California” at 4:10 p.m, Wednesday, Sept. 29 in Room 122 of Briggs Hall. This in-person will be the first of the UC Davis Department of Entomology and Nematology's fall seminars. Many of the others will be virtual.
“Growers and pest control advisors in California suspect that European earwigs (Forficula auricularia) damage young citrus fruit,” Kahl writes in her abstract. “However, very little is known about herbivory by earwigs on citrus fruit. Our work details characteristics of herbivory by earwigs on citrus fruit and the use of sticky and pesticide barriers to manage earwigs and other citrus pests.”
Kahl, awarded her doctorate in August, focused her research on understanding the role of European earwigs in California citrus; developing a whole systems approach to manage earwigs and other citrus pests; and feeding preferences of fort-tailed bush katydids and citrus thrips on California citrus.
Kahl is now an ecological pest management specialist at Community Alliance with Family Farmers, Davis. She leads projects and extension efforts on sustainable pest management tactics.
She received an ongoing grant in 2019 from the Citrus Research Board on “Characterizing Earwig Damage to Citrus Fruits, and Damage Prevention using Trunk Barrier Treatment.” She also received a National Science Foundation Graduate Research Fellowship, awarded in 2017, and a 2018-19 Keller Pathways Fellowship (for entrepreneurship) from the University of California.
Active in both the Entomological Society of America and the Ecological Society of America, she won first place in the Student 15-Minute Paper Competition at the 2016 meeting of the International Congress of Entomology; and second place in the Student 10-Minute Paper Competition at the 2019 meeting of the Entomological Society of America (ESA). She served on the Eastern Branch team that won second place in the ESA's 2016 Linnaean Games, now called the Entomology Games. She co-organized a seminar, “Agroecology with Communities: Cross-Disciplinary Collaborations Between Ecology, Agriculture and Social Science,” for the Ecological Society of America at its 2019 meeting.
Kahl received her bachelor's degree in biology from Whitman College, Walla Walla; her master's degree in entomology from the University of Maryland, College Park. At Whitman College, she researched the effects of reservoirs as habitat barriers on song sharing of the birds, dickcissels. At the University of Maryland, she focused her research topics on effects of red clover as a living mulch cover crop on arthropod herbivores, natural enemies, pollination and yield in cucumber; (2) consumptive and non-consumptive effects of wolf spiders on cucumber beetles and (3) effects of red clover living mulch on greenhouse gas emissions. She studied abroad in a six-month School for International Training program in Jaipur, Rajasthan, India in 2010. Her research topic: Village dairy production in Haryana and Orissa.
Her current activities include being the chapter leader for Women in Data (WID), Sacramento.
Kahl's exit seminar will be recorded for later viewing, according to seminar coordinator Shahid Siddique (ssiddique@ucdavis.edu), a nematologist and assistant professor, UC Davis Department of Entomology and Nematology. The seminars take place every Wednesday at 4:10 p.m. Many are virtual.
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