- (Focus Area) Pest Management
- Author: Kathy Keatley Garvey
Two USDA forest entomologists will be presenting in-person and virtual seminars at the University of California, Davis on Tuesday, Jan. 31 and Wednesday, Feb. 1. If you're around UC Davis, drop in and hear the seminars, sponsored by the UC Davis Department of Entomology and Nematology. They'll take place at 4:10 p.m. in 122 Briggs Hallon Kleiber Hall Drive, located near the UC Davis police and fire departments.
Or, you can access the seminars on Zoom.
The first speaker is Justin Runyon, who will deliver his seminar at 4:10 p.m., Tuesday, Jan. 21 on "Secrets of a Long Life: Chemical Defense of Bark Beetles by Bristlecone Pines." The Zoom link:
https://ucdavis.zoom.us/j/
Next is Chris Fettig, who will speak at 4:10 p.m., Wednesday, Feb. 1 on "Bark Beetles: How Tiny Insects Are Transforming Western Forests with a Little Help From Climate Change." The Zoom link:
https://ucdavis.zoom.us/j/95882849672
Host for both seminars is UC Davis doctoral student Crystal Homicz, who is advised by Fettig. She began her studies with forest entomologist and chemical ecologist Steve Seybold (1959-2019). Her dissertation research focuses on western pine beetle and red turpentine beetle interactions with forest disturbances, such as drought, wildfire and prescribed fire.
"Bristlecone pines are iconic species that can live to be thousands of years old," Runyon says in his abstract. "Secrets to their great longevity include a stable environment, sectored architecture, and avoidance of fire. However, to survive thousands of years, these trees must also avoid getting attacked by tree-killing bark beetles."
"Only in the last few years have we begun to uncover how bristlecone pines do this," he related. "We use field work, chemical ecology and laboratory assays to understand interactions between long-lived bristlecone pine species (Great Basic Bristlecone pine and foxtail pine), co-occurring limber pine, and the mountain pine beetle (MPB). I will talk about recent and going research examining (1) the plant volatile cues used by host-searching MPBs, (2) the terpene-based phloem defenses used against MPB larvae, and (3) tradeoffs between constitutive and induced defenses across these pine species. Understanding these interactions provides insight into the longevity of bristlecone pines, the implications for these species under climate change, and development of management tool to protect trees from bark beetles."
Runyon, based on the Montana State University (MSU) campus in Bozeman, received his bachelor's degree in biology and mathematics in 1998 from the University of Virginia's College at Wise, Va.; his master's degree in entomology from MSU in 2001; and his doctorate in entomology in 2008 from Pennsylvania State University Park, Pa.
In 2014, at a ceremony in Washington, D.C., he received the Presidential Early Career Award for Science and Engineering (PECASE), the highest honor bestowed by the U.S. government on science and engineering professionals in the early stages of their independent research careers.
Chris Fettig
"Bark beetles are a major disturbance in western forests," Fettig says in his abstract. "Several recent outbreaks of species such as mountain pine beetle, spruce beetle, and western pine beetle are among the most severe in recorded history. There is strong evidence that climate change has increased the impacts of bark beetles. For example, in California warming and exceptional drought resulted in mortality of more than a 100 million trees from 2014-2017. Much of this mortality was attributed to western pine beetle colonizing drought-stressed hosts. I will discuss observed and projected changes in climate, the direct and indirect effects of climate change on bark beetles and forests, and management actions that increase the resilience of forests to bark beetles and climate change."
Fettig received his bachelor's degree (1993) and a master's degree (1996) from Virginia Tech University, and his doctorate in forest entomology in 1999 from the University of Georgia.
Winter Seminars. Note that the Justin Runyon seminar is a specially scheduled seminar. The Chris Fettig seminar is part of the UC Davis Department of Entomology and Nematology's series of winter seminars, held on Wednesdays at 4:10 p.m. in 122 Briggs Hall. Urban landscape entomologist Emily Meineke, assistant professor, coordinates the weekly seminars. (See schedule.) She may be reached at ekmeineke@ucdavis.edu for any technical issues. A coffee social precede each seminar in158 Briggs from 3:30 to 4:10 p.m.
For general information about bark beetles, read the UC Statewide Integrated Pest Management Program's "How to Manage Pests in Gardens and Landscapes":
"Bark beetles, family Scolytidae, are common pests of conifers (such as pines) and some attack broadleaf trees. Over 600 species occur in the United States and Canada with approximately 200 in California alone...California now has 20 invasive species of bark beetles, of which 10 species have been discovered since 2002." The UC IPM information includes a chart of bark beetles common in landscapes.
- Author: Kathy Keatley Garvey
Fettig's seminar also will be virtual. The Zoom link:
https://ucdavis.zoom.us/j/95882849672
UC Davis doctoral student Crystal Homicz will host him.
"Bark beetles are a major disturbance in western forests," Fettig says in his abstract. "Several recent outbreaks of species such as mountain pine beetle, spruce beetle, and western pine beetle are among the most severe in recorded history. There is strong evidence that climate change has increased the impacts of bark beetles. For example, in California warming and exceptional drought resulted in mortality of more than a 100 million trees from 2014-2017. Much of this mortality was attributed to western pine beetle colonizing drought-stressed hosts. I will discuss observed and projected changes in climate, the direct and indirect effects of climate change on bark beetles and forests, and management actions that increase the resilience of forests to bark beetles and climate change."
Fettig advises Homicz, who began her studies with forest entomologist and chemical ecologist Steve Seybold (1959-2019). Her dissertation research focuses on western pine beetle and red turpentine beetle interactions with forest disturbances, such as drought, wildfire and prescribed fire.
Fettig received his bachelor's degree (1993) and a master's degree (1996) from Virginia Tech University, and his doctorate in forest entomology in 1999 from the University of Georgia.
Of his current research, he writes on the USDA website: "My personal research program has three major emphases: (1) determination of short and long-term implications to forest health of prescribed fire and/or mechanical fuel treatments (silvicultural thinning) used in the large-scale restoration of fire-adapted forest ecosystems, (2) development of chemical, silvicultural and semiochemical-based monitoring and management tactics for Dendroctonus and Ips bark beetles, and (3) determination of the role of semiochemicals in the behavior of bark beetle species of economic importance."
Fettig's most recent publication, "Fire and Insect Interactions in North American Forests," co-authored by Homicz and several other colleagues, appears in a 2022 edition of Current Forestry Reports. Abstract: "Fire has both positive and negative effects on insects. Bark beetle and defoliator epidemics have positive and negative effects on wildfires. Additional study of these relationships is warranted given the effects of climate change on forests and forest disturbances, recent declines in some pollinator species in North America, and interests in restoring fire-adapted forest ecosystems."
The UC Davis Department of Entomology and Nematology's winter seminars are held on Wednesdays at 4:10 p.m. in 122 Briggs Hall. All are virtual. They are coordinated by urban landscape entomologist Emily Meineke, assistant professor. (See schedule.) She may be reached at ekmeineke@ucdavis.edu for technical issues.
- Author: Kathy Keatley Garvey
The seminar, hosted by UC Davis doctoral student Crystal Homicz, begins at 4:10 p.m. in 122 Briggs Hall. The Zoom link: https://ucdavis.zoom.us/j/
"Only in the last few years have we begun to uncover how bristlecone pines do this," he related. "We use field work, chemical ecology and laboratory assays to understand interactions between long-lived bristlecone pine species (Great Basic Bristlecone pine and foxtail pine), co-occurring limber pine, and the mountain pine beetle (MPB). I will talk about recent and going research examining (1) the plant volatile cues used by host-searching MPBs, (2) the terpene-based phloem defenses used against MPB larvae, and (3) tradeoffs between constitutive and induced defenses across these pine species. Understanding these interactions provides insight into the longevity of bristlecone pines, the implications for these species under climate change, and development of management tool to protect trees from bark beetles."
Runyon, based on the Montana State University (MSU) campus in Bozeman, received his bachelor's degree in biology and mathematics in 1998 from the University of Virginia's College at Wise, Va.; his master's degree in entomology from MSU in 2001; and his doctorate in entomology in 2008 from Pennsylvania State University Park, Pa.
In 2014, at a ceremony in Washington, D.C., he received the Presidential Early Career Award for Science and Engineering (PECASE), the highest honor bestowed by the U.S. government on science and engineering professionals in the early stages of their independent research careers.
Runyon is also involved in assessing native plants desired by native bees. (See research and news story)
Homicz, advised by research entomologist Chris Fettig of the USDA's Pacific Southwest Research Station, Davis, began her studies with forest entomologist and chemical ecologist Steve Seybold (1959-2019). Her dissertation research focuses on western pine beetle and red turpentine beetle interactions with forest disturbances, such as drought, wildfire and prescribed fire.
The UC Davis Department of Entomology and Nematology's regularly scheduled Wednesday seminars are at 4:10 p.m. on every Wednesday through March 15. They are coordinated by urban landscape entomologist Emily Meineke, assistant professor. (See schedule.) She may be reached at ekmeineke@ucdavis.edu.
[Originally featured in the Winter 2022 Issue of UC IPM's Green Bulletin Newsletter]
Weeds can be a problem in any landscaped areas including around trees, shrubs, flower beds, or lawns and turf. As we move from cool weather to warmer temperatures, you will see winter weeds grow and become a problem in established landscape plantings. Effective control of weeds include hand-weeding, hoeing, mulching, and herbicide applications. Good management depends on early attention to where weeds are establishing and adjusting the conditions that allow them to thrive.
Managing weeds in landscape plantings
Each type of planting bed will have specific techniques that work best. In general, dense plantings will shade out most weeds. Regardless of the type of landscape bed, it's always best to control perennial weeds before planting. Herbicides are effective in many types of landscape plantings. They are most effective when integrated with cultural practices. Many of the herbicide active ingredients available for weed control in landscape plantings are only for use by pest management professionals.
Tree and shrub beds
Landscaped areas made up of trees and woody shrubs don't need as much preplant weed control as other types of beds. Control perennial weeds after planting using methods like mulching, hand pulling, and herbicide treatments. Suppress weed growth by laying down landscape fabric, then adding an inch of mulch on top to thoroughly cover the fabric. If needed, use a preemergence herbicide. Supplement with spot treatments of postemergence herbicides and hand-weeding.
Ground cover beds
Since ground cover is expected to fill the entire bed, landscape fabric is not suitable for weed suppression. Perennial weeds should be controlled before planting. If perennial grasses are encroaching, they can be controlled with selective herbicides like fluazifop, clethodim, or sethoxydim. Spot applications of glyphosate or glufosinate can be used on perennial weeds. Mulch the bed to control annual weeds until the ground cover fills the area. Some hand weeding might be needed.
Annual flower beds
As with other landscaped areas, a dense planting will shade out weeds. Annual weeds can be managed with mulches, frequent cultivation, and hand-weeding. Periodic cultivation (every 3 to 4 weeks) will suppress many weeds. Since nonselective herbicides can't be used after planting annual beds, it's easier to manage perennial weeds beforehand. If cultural methods aren't working to control perennial grasses, you can use grass-selective herbicides with clethodim or fluazifop. Check the product label to be sure that it won't harm the annual flowers in the bed.
Herbaceous perennial beds
Manage weeds in herbaceous perennial beds as you would an annual flower bed. Be sure to get rid of perennial weeds before planting since the bed will be growing for more than one season. Use landscape fabric where possible along with mulches. You might need to supplement with hand-pulling followed by preemergence herbicides. Be aware that fewer perennial plants are included as sites on herbicide labels.
Mixed plantings
A planting bed of a mix of woody and herbaceous plants is a more complex situation. Different areas of the bed might need different treatments. Post-plant herbicide choices are limited so site preparation is critical in this type of bed. Plant woody species first and control the perennial weeds. After the first two growing seasons, add the herbaceous plants. Shade the soil with close planting. Group plants within the bed based on their weed management needs.
Cool weather weeds in landscapes
Some of the most troublesome weeds in planting beds during late winter and early spring are common groundsel, oxalis, mallows, and nutsedges.
Common groundsel
Common groundsel is most prolific in cool weather, germinating from seeds this time of year. This weed produces many seeds and can rapidly infest landscape beds. It is best controlled before it flowers. Mulch is highly effective at controlling common groundsel. Young plants can be hoed out. Diquat or glyphosate-based herbicides will control common groundsel in landscape beds.
Mallows
Mallows are annual weeds that begin growing with the first rains so you may already be seeing these sprouting up in landscape beds. This plant develops a long taproot so it should be pulled when it has four or fewer true leaves. At least three inches of mulch is needed to suppress mallow. Young mallow plants might be managed with 2,4-D products, but this herbicide will injure broadleaf plants growing nearby.
Nutsedges
Purple and yellow nutsedge are perennial plants that sprout in spring from tubers. Remove these weeds as soon as possible to prevent tuber production. Tubers (sometimes referred to as “nuts” or “nutlets”) are key to nutsedge survival. Once established, nutsedge plants are difficult to control. They don't grow well in shade so dense plantings of ground cover or shrubs will suppress nutsedges. Few herbicides are effective at controlling nutsedge.
Oxalis (creeping woodsorrel and Bermuda buttercup)
While Oxalis (creeping woodsorrel) can bloom almost any time during the year, spring is a time of heavy flowering and seed formation. Buttercup oxalis sprouts in fall and is a major weed in ornamental plantings. Hand pulling can control these weeds but be aware that mowing can spread creeping woodsorrel. Landscape fabric with two to three inches of an organic mulch on top can control oxalis. There are no selective postemergence herbicides for creeping woodsorrel in ornamental plantings.
Herbicide injury
Desired plants could be injured when herbicides are used in established landscape beds. Herbicide damage symptoms vary depending on the herbicide and the plant. Symptoms can include yellowing, bleaching, distorted growth, and death of leaves. Avoid herbicide injury by following the label about the site, plant, and application rate. Granular formulations are less likely to damage plants than sprays. When using a nonselective liquid herbicide, apply on a calm day using low pressure and large droplets. Use a shielded sprayer to avoid contact with nontarget plants. If plants are injured from soil-applied herbicides, the damage is often temporary but can cause growth inhibition. Adding organic amendments and keeping the soil moist will help the herbicides to break down faster.
For more details and for information about weed management before planting a landscape bed, see Pest Notes: Weed Management in Landscapes.
- Author: Kathy Keatley Garvey
From boring beetles to burying beetles...and beetles from Belize and more...
And you're invited.
The Bohart Museum of Entomology is hosting an open house, themed "Beetles," from 1 to 4 p.m., Sunday, Jan. 24 in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. It's free and family friendly.
A Cal Fire display of bark beetle specimens; children's activities by Project Learning Tree California; and a UC Davis graduate student's display of tree cores and boring tools are among the new additions to the open house.
Also scheduled to participate is carabid beetle expert Kipling "Kip" Wills, associate professor with the UC Berkeley Department of Environmental Science, Policy and Management, announced Lynn Kimsey, director of the Bohart Museum and a UC Davis distinguished professor of entomology.
Cal Fire
Curtis Ewing, a senior environmental scientist with Cal Fire's Forest Entomology and Pathology, will show specimens of "many different invasive and native species that do or could impact forest health in California." They include such specimens as Ips engravers, Western pine beetles, flat-headed borers and various long-horned beetles. Among others on the list: coconut rhinoceros beetles, South American palm weevils, Asian longhorned beetles, emerald ash borers, gold spotted oak borers, Eucalyptus borers, invasive shot hole borers and Mediterranean oak borers.
"I will have a table with displays and a USB microscope hooked up to a screen and specimens," Ewing said, "so people can put different, small, species under the scope."
What should people know about bark beetles and the damage they cause?
"Native bark beetles, roundheaded borers and flatheaded borers are a natural part of our native forest ecosystems," Ewing said. "When our forests receive adequate amount of rain and do not suffer from extreme heat stress, these beetles thin the forest by attacking weakened and diseased trees. During times of high water stress, which is a combination of low rainfall, and often more importantly, high levels of heat stress, these native beetles can kill large forest areas. Trees in our cities and towns are threatened by a number of introduced beetles that attack and kill healthy trees. The beetles are able to attack trees that are otherwise healthy and happy, not suffering from drought or heat, because they lack an effective defense against these new alien."
Project Learning Tree California
Jonelle Mason, a UC Agriculture and Natural Resources (UC ANR) employee and coordinator of Project Learning Tree (PLT) California, an initiative of the Sustainable Forestry Initiative (partnered with the California Department of Forestry and Fire Protection-Urban and Community Forestry Program), will be tabling children's activities in the hallway of the Academic Surge Building. They will include a hands-on peppermint beetle activity.
"We specifically have an activity focused for K-5 called peppermint beetle!" Mason related. "It models how animals use a sense of smell to respond to the environment around them and identifying smells in our daily lives. "This is a super fun activity to present and then bring back to kids! It specifically will focus on bark beetles."
Mason, a master herpetologist and a former zookeeper with a bachelor's degree in biology, worked with exotic animals for 12 years before joining the PLT team to continue "my fierce love for nature and environmental education." As a zookeeper, she worked "with some of the largest animals on the planet" and "used animal training to influence thousands of people throughout the country."
UC Davis graduate student Jennifer Cribbs of the Graduate Program of Environmental Policy and Management, will display tree cores and boring tools. She focuses on restoration, botany and forest dynamics. Cribbs holds a bachelor's degree in psychology from Stanford University. Following her graduation, she worked for the National Park Service, the U.S. Forest Service, and the U.S. Geological Survey where her job duties ranged from tagging endangered sea turtles at Padre Island National Seashore to leading a field crew focused on assessing the health of white pines in Sequoia and Kings Canyon National Park.
Previously announced:
Burying Beetles
Tracie Hayes, a doctoral candidate and burying beetle researcher in the laboratory of Professor Louie Yang, UC Davis Department of Entomology and Nematology, will discuss her work and present a video she created, "A Clearance of Death on Behalf of Life" at https://youtu.be/cGLOE7SrbiU. She will field questions about the insect and her research. (See news story)
Beetles from Belize
Folsom Lake College professor Fran Keller, a Bohart Museum scientist and a UC Davis doctoral alumna of entomology, will discuss the beetles that she and other scientists collected in Belize. (See Bug Squad blog)
Arts and Crafts
The family arts-and-craft activity will be to color a drawing of a carrion beetle, the work of Tracie Hayes.
The Bohart Museum, dedicated to "understanding, documenting and communicating terrestrial arthropod diversity," was founded in 1946 and named for UC Davis professor and noted entomologist Richard Bohart. In addition to its global collection of eight million insect specimens, it houses a live "petting zoo," featuring Madagascar hissing cockroaches, walking sticks and tarantulas; and a year-around gift shop, stocked with insect-themed books, posters, jewelry, t-shirts, hoodies and more.
