- (Focus Area) Pest Management
- Author: Kathy Keatley Garvey
Oh, there ain't no bugs on me
There ain't no bugs on me
There may be bugs on some of you mugs
But there ain't no bugs on me
You can hear it on YouTube.
UC Davis distinguished professor James R. Carey of the Department of Entomology and Nematology, drew national news media coverage in 1991 when he declared that the medflies are "established" here, that the "recurring outbreaks" are not caused by tourists continually bringing infested fruit to California in their airline baggage.
Today Carey says that California's fruit fly invasion is in "crisis mode."
The professor will present a Department of Entomology and Nematology seminar on "California's Fruit Fly Invasion Crisis" at 4:10 p.m., Monday, June 3 in Room 122 of Briggs Hall. It also will be on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/9 5882849672.
"After seven decades of near-continuous outbreaks in scores of California cities, tephritid fruit fly invasions (e.g., Mediterranean, oriental, peach, and Mexican fruit flies) are reaching critical mass, with many of the annual eradication programs morphing into below-the-radar, never-ending fruit fly control programs," Carey says in his abstract. "Permanent establishment of any one of these tropical species has the potential to shut down the multi-billion dollar domestic and foreign markets for hundreds of California fruit and vegetable crops."
"I will present an overview of the long-developing crisis, discuss lessons learned from analysis of fruit fly detection databases, and argue that, in order to have any chance at stemming this ever-rising tide, CDFA and the USDA urgently needs to switch from their historic, ad hoc eradication strategy to a new one that is evidence-based and far more scientific."
Carey served on the CDFA's Medfly Scientific Advisory Panel from 1987-1994, testified to the California Legislature "Committee of the Whole" in 1990 on the Medfly Crisis in California, and authored the paper "Establishment of the Mediterranean Fruit Fly in California" (1991, Science 258, 457).
Carey is a fellow of four professional societies: the Entomological Society of America, the American Association for the Advancement of Science, the California Academy of Sciences, and the Gerontological Society of America. He is former director (2003-13) of a 11-university consortium funded by the National Institute on Aging (NIH/P01) on the evolutionary ecology of lifespan.
- Author: Luis Espino
I received several calls and comments about issues with tadpole shrimp this spring. While this pest is well known to growers and PCAs, it can still be difficult to manage during planting time. Mistiming of insecticide application can result in shrimp damage. Tadpole shrimp develop fast, and really fast when it is warm. This spring was warmer than last year during mid to late May, when most of the rice was being flooded and planted. If a field takes long to flood and seed, the shrimp have more time to develop and may injure seedlings as soon as they start germinating in the field. What shrimp size can injure rice? If you can see the shrimp, they can injure rice. However, larger shrimp will cause more injury than smaller shrimp. The figure below shows how, in a field infested with TPS, the stand is reduced more the later the field is seeded after flood (DAF).
Some of the fields where shrimp injury occurred this year are fields where pyrethriods do not control shrimp anymore. In these fields, Dimilin is working well. However, remember that Dimilin may take a few days longer to clear up the shrimp than pyrethroids and copper, especially when the shrimp are large.
When shrimp injury occurs soon after seeding, they will feed on the emerging coleoptile and radicle, completely consuming these tissues. When this happens, seeds won't recover. If only some of the tissue is consumed, seedlings may be able to continue growing once the shrimp is controlled. The picture below shows seedlings where the coleoptile and radicle have been consumed compared to two uninjured seedlings at the bottom of the picture.
If a field is damaged by tadpole shrimp, reseeding is an option. Some trials conducted a couple of years ago by Bruce Linquist showed that the optimum stand is about 25 plants/ft2. Rice plants can compensate when the stand is reduced. For example, when the stand is reduced to 12.5 plants/ft2 (half the optimum), yield is reduced only 10%. In general, reseeding should be considered when the stand is reduced to 10 plants/ft2 or less. Draining the field before reseeding increases the likelihood of establishment of the reseed, but it may not be possible in all cases. When reseeding, use a higher seeding rate to increase the chances of establishment and make sure the shrimp have been controlled. As a grower told me a few years ago, remember that reseeding is a bit of a gamble.
- Author: Kathy Keatley Garvey
"It's really serious," says UC Davis distinguished professor James R. Carey, a noted authority on the invasion of tropical fruit flies.
Professor Carey will discuss his findings at a UC Davis Department of Entomology and Nematology seminar at 4:10 p.m., Monday, June 3 in Room 122 of Briggs Hall. His seminar, titled "California's Fruit Fly Invasion Crisis," also will be on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/9 5882849672.
"After seven decades of near-continuous outbreaks in scores of California cities, tephritid fruit fly invasions (e.g., Mediterranean, oriental, peach, and Mexican fruit flies) are reaching critical mass, with many of the annual eradication programs morphing into below-the-radar, never-ending fruit fly control programs," Carey says in his abstract. "Permanent establishment of any one of these tropical species has the potential to shut down the multi-billion dollar domestic and foreign markets for hundreds of California fruit and vegetable crops."
"I will present an overview of the long-developing crisis, discuss lessons learned from analysis of fruit fly detection databases, and argue that, in order to have any chance at stemming this ever-rising tide, CDFA (California Department of Entomology and Nematology) and the USDA (U.S. Department of Agriculture) urgently need to switch from their historic, ad-hoc eradication strategy to a new one that is evidence-based and far more scientific."
Carey served on the CDFA's Medfly Scientific Advisory Panel from 1987-1994, testified to the California Legislature "Committee of the Whole" in 1990 on the Medfly Crisis in California, and authored the paper "Establishment of the Mediterranean Fruit Fly in California" (1991, Science 258, 457).
Carey is a senior scholar in the Center for the Economics and Demography of Aging at UC Berkeley and former vice chair of the UC Davis Department of Entomology. He focuses his research on insect biodemography, mortality dynamics, and insect invasion biology. He joined the Department of Entomology in 1980.
Fellow of Four Professional Societies. Carey is a fellow of four professional societies: the Entomological Society of America, the American Association for the Advancement of Science, the California Academy of Sciences, and the Gerontological Society of America. He is former director (2003-13) of a 11-university consortium funded by the National Institute on Aging (NIH/P01) on the evolutionary ecology of lifespan.
He co-authored the book Biodemography: An Introduction to Concepts and Methods (Carey, J. R. and D. Roach. 2020; Princeton University Press) and authored three previous books, Demography for Biologists (Oxford University Press 1993), Longevity (Princeton University Press, 2003), and Longevity Records: Life Spans of Mammals, Birds, Amphibians and Reptiles (Odense, 2000). He has written more than 250 journal articles and book chapters. For any technical issues with Zoom, contact seminar coordinator Brian Johnson, associate professor, at brnjohnson@ucdavis.edu.
Resources:
- The 30?Year Debate on a Multi?Billion?Dollar Threat: Tephritid Fruit Fly Establishment in California, June 8, 2017, American Entomologist
- Behind the Scenes in the California Fruit Fly Invasion, Aug. 6, 2013, UC Davis Department of Entomology and Nematology
- From a Trickle to a Flood: The Large-Scale Cryptic Invasion of California by Tropical Fruit Flies, October 2013, Proceedings of the Royal Society B
- Establishment of the Mediterranean Fruit Fly in California, 1991, Science
- Author: Lauren Fordyce
- Contributor: Roger A Baldwin
In this blog article we answer some frequently asked questions about moles, voles, and gophers and their management.
How can I tell if I have moles, voles, gophers, or something else?
Moles: look for circular or volcano-shaped mounds with the plug in the middle, or a plug may not be apparent. The soil of mole mounds tends to be clumpier than gophers. Moles sometimes leave a raised ridge just beneath the soil surface while hunting for food.
Voles: look for aboveground runways that connect burrow openings. Grass usually covers the burrows. Voles can girdle trees aboveground while gophers girdle trees belowground.
Gophers: look for crescent or horse-shoe shaped mounds with a plug off to one side. Tunnels are 6-12 inches below ground.
Can gophers climb fences or into raised garden beds?
To some extent, yes. It is important to have an above-ground exclusionary device in place to keep them out of desired areas. Usually 12 inches of fencing is sufficient since they are not great climbers.
Should I use gopher baskets or underground fencing?
Gopher baskets can be used to protect individual plants. Underground fencing might be justified for valuable ornamental shrubs, landscape trees, or garden beds. Keep in mind metal wire will rust and disintegrate after several years to prevent plant roots from being strangled. Galvanized wire, and especially stainless-steel wire, will last much longer. Read more on gopher exclusion. For voles, wire fences or aluminum flashing around gardens can be effective. Learn more about vole exclusion. Installing a vertical underground barrier may provide temporary relief for moles. Read more about mole exclusion.
Should I treat the soil to remove insects or grubs to prevent moles, voles, and gophers from feeding?
Treating the soil with an insecticide would have no impact on gophers or voles because they feed on plant material, not insects. Doing so might reduce mole activity, but the effectiveness of this approach has not been proven.
What plants deter these pests?
Plants, including Euphorbia lathyrus, castor bean, Ricinus communis, and garlic have not proven through conducted research trials to be effective at protecting plantings from moles, voles, or gophers.
Are there any natural repellents that work?
Repellents containing castor oil have shown some repellency for moles in the eastern U.S., but their effectiveness against moles in CA is unknown. No other repellents have proven effective at protecting gardens or other plantings from moles, voles, or gophers. They are also not practical as you must apply them before damage occurs and some products may not be labeled for use on edible plants.
What traps are most effective?
The most effective trap is going to depend on which animal is present.
For gophers, 2-pronged pincer traps, such as the Macabee, Cinch, or Gophinator, can be used. Another popular type is the choker-style trap, such as the Gopherhawk. Learn more about gopher traps. For voles, a standard mouse trap can be effective. Learn how to place traps correctly. Harpoon, scissor-jaw, and pincer-style traps can be used for moles. Learn more about trapping moles.
Can I flood their burrow to kill them?
Flooding mole and vole burrows is ineffective at controlling them. For gophers, flooding can force them out of their burrows but you must kill them when they exit the burrow, otherwise they will return once it dries out. Since their burrows can be extensive and deep, flooding is usually just a waste of water.
What fumigants can I use?
Burrow fumigants with smoke or gas are not effective for moles, voles, or gophers.
The general public cannot use aluminum phosphide. This is a restricted use pesticide and often cannot be used in residential areas. You must have a pesticide applicator license to use it.
Pressurized exhaust machines and carbon dioxide injection devices are expensive and only practical for large infestations.
Are poison baits dangerous for nontarget wildlife and predators? How can they be used safely?
Toxic baits can harm nontarget wildlife, but since baits are placed inside burrows and the pest usually dies inside the burrow, predators and other wildlife are less likely to encounter the toxic bait and poisoned animals. Certain baits, known as first-generation anticoagulants (e.g., warfarin and chlorophacinone) generally require consumption over the course of several days to be effective–making them a potentially safer option. Always be sure to read the product label and make sure it will work against your specific pest, and be sure to understand the potential risks when using these toxicants. Note that not all products are legal for all 3 pests.
Will predatory birds, dogs, or cats control them?
Many predators including coyotes, foxes, badgers, weasels, cats, gulls, and especially hawks and owls eat voles and gophers. However, in most cases predators can't keep their populations below damaging levels. Installing barn owl boxes will likely not be enough to control these burrowing animals in urban settings either.
Do ultrasonic, sound-emitting, or vibrating devices work?
Electromagnetic or ultrasonic devices settings are ineffective against voles. Gophers and moles are not frightened by these devices.
How can you tell if a burrow or mound is active?
For moles and gophers, always look for the freshest activity as indicated by moist soil on the mound. The fresher the mound, the more likely the animal is still using the tunnel. For voles, look for fresh grass clippings and fecal pellets around burrow entrances and along runways.
How do I prevent moles, voles, and gophers from establishing?
Limit dense vegetation including weeds and heavy mulch that provide them protection. They are less common in non-vegetated areas.
How can you dispose of dead moles, voles, or gophers?
Bury them or place in a plastic bag in the trash. Never touch them with your bare hands as they can carry infectious pathogens and parasites.
To learn more about management of these pests, visit the Pest Notes fact sheets below:
Questions for this FAQ collected from the Moles, Voles, and Gophers webinar on May 16th, 2024.
- Posted by: Gale Perez
Sterile Pollen Technique Shows Promise for Palmer Amaranth Weed Control
Newly published research provides a novel and sustainable weed-management strategy
WESTMINSTER, Colorado – 22 May2024 – Recently published research in the journal Weed Science shows that a sterilization technique commonly used to control insect pests can be modified to control weeds that require pollination to reproduce. More specifically, the researchers determined that employing a sterile pollen technique (SPT) could effectively disrupt Palmer amaranth (Amaranthus palmeri S.) reproduction.
Palmer amaranth remains among the most detrimental weeds in North American agriculture, and its resistance to several herbicide groups makes its control a serious challenge. Yet, researchers in this study were able to find a promising new control method for Palmer amaranth and possibly for many other difficult-to-control weeds.
“Our results indicate that SPT, using irradiated pollen, can be a valuable approach for reducing weed-seed production,” says Mohsen B. Mesgaran, Ph.D., a plant sciences assistant professor at the University of California Davis, and the article's corresponding author. “SPT also holds potential for broad-spectrum weed control by mixing sterile pollen from multiple weed species in a single application.”
Additionally, the researchers found that SPT shows promise for managing troublesome herbicide-resistant weeds that have survived in-season control efforts.“We observed the greatest reduction in seed set when irradiated pollen was introduced to the stigma through artificial pollination prior to open pollination,” notes Mesgaran. “It appears that irradiated pollen exerts a preventive effect on naturally occurring pollen that arrives later.”
While the researchers determined that a dose of 300 units of ionizing radiation (Gy) strikes the optimal balance to achieve both efficient Palmer amaranth pollination and seed sterility, challenges still remain. For example, irradiated pollen is currently less competitive than naturally occurring pollen. Thus, field managers may need to employ additional measures to successfully control Palmer amaranth with SPT, such as dispersing irradiated pollen in the field before male anthesis and releasing it multiple times.
More information about SPT and Palmer amaranth control can be found in the article (by Wenzhuo Wu and Mohsen B. Mesgaran), “Exploring sterile pollen technique as a novel tool for management of Palmer amaranth (Amaranthus palmeri).” The research is featured in Volume 72, Issue 3 of Weed Science, a Weed Science Society of America journal, published online by Cambridge University Press.
Original source: Weed Science Society of America (https://wssa.net/2024/05/sterile-pollen-technique-shows-promise-for-palmer-amaranth-weed-control/)
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