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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- Author: Kathy Keatley Garvey
Nematologist and plant pathologist Shahid Siddique, assistant professor, UC Davis Department of Entomology and Nematology and coordinator of the department's seminars for the 2021-22 academic year, has announced the list of fall quarter seminars, which begin Sept. 29 and conclude Dec. 1.
All will be held at 4 p.m. on Wednesdays, Pacific Time, and will include both in-person and virtual seminars.
"We we have an exciting list of seminars that includes both national and international speakers," Siddique said.
The in-person seminars will take place in Room 122 of Briggs Hall, located off Kleiber Hall Drive. These seminars will be recorded for later viewing.
Three of the seminars will be virtual. "Virtual seminars will be accomplished using the Zoom meeting software package," Siddique related. A Zoom link will be provided a week before the seminar.
First on tap will be the exit seminar of doctoral candidate Hanna Kahl of the lab of UC Davis distinguished professor Jay Rosenheim. She will speak on "Herbivory of Citrus Fruit by European Earwigs in California" at 4 p.m., Wednesday, Sept. 29. This will be an in-person seminar.
No seminar will be held Nov. 3, which conflicts with the annual meeting of the Entomological Society of America (ESA), set Oct. 31-Nov. 3 in Denver, Colo. Many faculty attend the annual meeting.
The seminars are open to all interested persons.
Siddique joined the UC Davis Department of Entomology and Nematology in July 2019 after serving as a research group leader for several years at the University of Bonn, Germany. Research in the Siddique lab focuses on basic as well as applied aspects of interaction between parasitic nematodes and their host plants. "The long-term object of our research is not only to enhance our understanding of molecular aspects of plant–nematode interaction but also to use this knowledge to provide new resources for reducing the impact of nematodes on crop plants in California."
For further information on the seminars, contact Siddique at ssiddique@ucdavis.edu.


Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client: Help!!! I'm a relatively new vegetable gardener. I just planted my summer vegetable garden seedlings this week. Within the week I'm finding severely damaged zucchini seedlings with holes in the leaves and for some of them the entire seedling is gone. What is doing this? And what can I do to prevent such damage?
Control of these pests in the garden is usually a combination of methods. Hand picking at night with a flash light can be a quick and easy way to control the population. As you pick them off your plants or off the ground you can drop them into a container of mild soapy water. I personally like to wear garden gloves for this task. The water can be drained off in an out of the way spot in your yard and the snails and slugs disposed of in your trash bin.

The fourth possibility is birds. Pesky birds can do a lot of damage to your tender young plants. However, they are also your "friend" for all the garden pests they feed on as well as being protected by law. If birds are the "problem", to control the birds you will need to get some "bird netting" over your plants. Half-inch diameter PVC pipe works well for making an arch or tent over your plants. The method would be to drive 24" pieces of ¼ inch re-bar into the ground about 2 to 3 feet apart along BOTH sides of your plants (and opposite one another) far enough apart so that the PVC can be readily bent into an arch and slide over both of the opposite re-bars,. Stretch your bird netting over the arches and secure it in place with clips, string or twist-ties. You can also find some other methods of making these arches on YouTube videos at https://www.youtube.com/watch?v=vEn-XQ5nA4k
Free UC Guidance on Snail & slug Management in the garden
(includes videos on identification of pest, applying bait, etc.):
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7427.html
Free UC Guidance on Earwig Management in the garden:
http://ipm.ucanr.edu/PMG/PESTNOTES/pn74102.html
I would do the nighttime check for snails and slugs first and try some of the trapping methods before I went to the trouble and expense of putting up bird netting. With a little effort I believe you can get the problem under control. However, the sad news is it looks to me like the zucchini plant will need to be pulled out and replanted as there does not seem to be enough leaf material left to sustain the plant. There is some good news here though, it's early in the growing season and the new zucchini will catch up in no time.
Help Desk of the UC Master Gardener Program of ContraCostaCountyf (BHD)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/).