- Author: Ben Faber
UC Riverside is testing whether a sesame seed-sized wasp can control a pest that could seriously damage California crops including wine, walnuts, and avocados.
The pest, a sap-sucking spotted lantern fly, is originally from China and was first detected five years ago in Pennsylvania. Since then, large populations have spread rapidly to grape vines, apple trees, and other plants in New York, Delaware, New Jersey, Maryland, and Virginia.
Experts believe the lantern fly is likely to make its way to California soon.
Mark Hoddle, director of the Center for Invasive Species Research at UC Riverside, explains why the lantern fly is so harmful.
“It secretes copious amounts of “honeydew,” a waste product that encourages black, sooty mold and damages a plant's ability to grow,” he said. The honeydew also attracts undesirable insects such as ants and hornets.
The impacts could extend well beyond California. According to industry reports, the state is the world's fourth-largest wine producer, selling an estimated $35 billion domestically and exporting $1.5 billion annually.
Around 44% of nonnative insects arriving in California were first established elsewhere in the U.S. Given the speed with which the spotted lantern fly has spread, Hoddle realized the state needed a proactive approach to this predictable problem.
“Normally, when a bug shows up, we try to contain and eradicate it,” Hoddle said. “But by the time the population is found, it tends to already be widespread and hard to handle.”
The state Department of Food and Agriculture recently granted Hoddle $544,000 to test whether a tiny parasitic wasp, also originally from China, could be the solution to the looming problem. Hoddle explained that the wasp has a needle-like appendage it uses to lay its own eggs inside the lantern fly's eggs. While developing, the wasp larvae eat and kill their hosts, and then emerge after chewing escape holes through the lantern fly eggs.
These wasps pose no threat to plants or people, but before they can be used to control the lantern fly, Hoddle must prove they won't cause unnecessary harm to other native insects. “We can't just release a Chinese parasite into the wild in California,” Hoddle said. “Chances are low it will harm the wrong targets, but we have to be sure.”
Safety testing will be conducted in a highly secure quarantine facility at UC Riverside. Native lantern flies, the subjects of safety testing, will be collected from natural areas in California and southern Arizona this summer.
Though the wasp is now being evaluated as a biological control on the East Coast, populations of lantern fly there have already grown large enough to cause significant concern for the grape industry, Hoddle said.
A spotted lantern fly's wingspan is about 1.5 inches, and at most they can fly a few hundred feet at a time if they're assisted by the wind. The lantern fly has spread so fast in part because the females lay eggs on nonbiological materials, such as train cars, motor homes, wooden pallets, and trucks that inadvertently move them into new territories.
“Anyone on the East Coast driving to California should be especially vigilant about checking their vehicle for egg masses before they make the journey,” Hoddle warned. “Failing to notice them could have serious consequences.”
Hoddle's testing will take roughly three years, and he estimates that this may be around the time when the wasps will be needed in California. “We hope to be ready to release these wasps immediately when the spotted lantern fly shows up, giving us a really strong head start on the invasion,” he said.
reposted from: https://news.ucr.edu/articles/2019/06/17/looming-insect-invasion-threatens-california-wine-and-avocados
Great video of Lantern Fly life stages from Penn State
https://www.youtube.com/watch?v=Wumtju2_0JM
Photo: Lantern fly egg mass
/article>- Author: Ben Faber
Biological control is the management of pests and their damage by the beneficial action of parasites (parasitoids), pathogens, and predators. These beneficial organisms, collectively, are named natural enemies.
Conserving (or protecting) and releasing natural enemies are important components of integrated pest management (IPM). In most situations, employing practices that conserve natural enemies is more effective, and less expensive and time consuming, than purchasing and releasing them.
Learn about the specific situations where purchasing and releasing parasites and predators can increase the effectiveness of biological control. Before purchasing natural enemies, consult the University of California (UC) IPM Pest Management Guidelines for that crop to learn whether UC research has shown that releasing them is effective. Some natural enemies on the market have never been demonstrated to effectively control any agricultural pest in California.
Obtaining Natural Enemies
Natural enemies can be purchased directly from various producers (companies that rear them) and suppliers (companies that purchase from producers and repackage and resell them). Some sources of parasites and predators are members of the Association of Natural Biocontrol Producers (ANBP). All ANBP members formally agree to a code of ethics and standardized methods.
Natural enemies purchased by users are commonly delivered via shipping services. Purchase parasites and predators only from in-state providers. It is illegal to obtain insects and other arthropods outside of California and carry or have them shipped across state lines without a permit from agricultural officials. Some pest control advisers and pest scouts will procure and release natural enemies as a service for growers.
Methods for Releasing Natural Enemies
Two methods for releasing natural enemies are inoculation and inundation:
- Inoculation—relatively few natural enemies are released. The offspring of these natural enemies provide biological control, not the individuals released.
- Inundation—large numbers of natural enemies are released, often several times over a growing season. The natural enemies released, and possibly their offspring, provide biological control.
The mealybug destroyer is an example of a natural enemy that is only released through inoculation—at relatively low numbers once per year early in the growing season. Aphytis melinus and Trichogramma parasites are released by inundation—at regular intervals over the growing season—to control California red scale and eggs of pest moths, respectively. Both inoculation and inundation can be used with predatory mites, depending on the situation.
Releasing Natural Enemies Effectively
Releasing natural enemies is most likely to be effective in situations where: 1) University of California researchers or other pest management experts have previously demonstrated success and 2) some level of pests and their damage can be tolerated in that crop. Desperate situations are not good opportunities for releasing natural enemies. Pests or their damage may already be too widespread for any release of parasites or predators to prevent economic loss of crop quality or quantity.
Increase the likelihood that natural enemy releases will be effective by
- Accurately identifying the pest and its natural enemies.
- Learning about the biology of the pest and its natural enemies.
- Releasing the appropriate natural enemy life stage and species.
- Releasing when the pests' vulnerable life stage(s) are present and at numbers that can be controlled by natural enemy releases.
Natural enemies are unlikely to be effective when released as if you were applying a pesticide. Instead, anticipate pest problems and begin making releases before pests are too abundant or economic damage is imminent.
- Remember that natural enemies are living organisms that require food, shelter, and water. Protect them from extreme conditions. For example, release them at night or early in the day during hot weather.
- Avoid applying broad-spectrum, residual (persistent) insecticides and miticides, and in some situations certain systemic or other pesticides, before or after releasing natural enemies. When needed, use pesticides selectively. For example, spot spray only where pests are abundant but localized.
Common reasons for the lack of satisfactory biological control after releases include the
- Application of broad-spectrum, residual insecticides, or in some situations systemic or other pesticides, prior to or after a release.
- Incorrect timing of release.
- Release of the wrong natural enemy for the pest situation.
- Release of a natural enemy species that is known to be ineffective.
For information on the use of biological control, see the UC IPM Pest Management Guidelines for your crop and specific pests. Most crops have a table called “Relative Toxicities of Insecticides and Miticides to Natural Enemies and Honey Bees” in the “General Information” section. Use these resources to guide pesticide selection to conserve natural enemies and improve biological pest control.
More Information
- Association of Natural Biocontrol Producers, Clovis, CA
- Grower Guide: Quality Assurance of Biocontrol Products (pdf), Vineland Research and Innovation Centre, Ontario
- Insectary Plants
- Natural Enemies Gallery
- Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control
- Protecting Natural Enemies and Pollinators
- UC IPM Pest Management Guidelines
this is a repost from:
Photo: Adult Aphytis melinus parasite laying her egg in California red scale, Aonidiella aurantii. Releases are most effective when ants are controlled, dust is minimized, and broad spectrum pesticide applications are avoided. Credit: Jack Kelly Clark, UC IPM Program
/h2>/h2>/h2>/h2>- Author: Ben Faber
It seems the humble earwig that can cause so much damage in citrus orchards in some years on some small trees can be a great boon in biocontrol. Read on:
WSU scientists unmask the humble earwig as an apple-protecting predator
By Seth Truscott,
College of Agricultural, Human, and Natural Resource Sciences
https://news.wsu.edu/2019/06/05/wsu-scientists-unmask-humble-earwig-apple-protecting-predator/
Helping Northwest apple growers protect their crops, WSU scientists have found new proof that earwigs are actually valuable predators in apple orchards, rather than the creepy, crawly, apple‑damaging pests they're sometimes assumed to be.
In the May 2019 edition of the journal Biological Control, Robert Orpet, recent doctoral graduate at Washington State University's Tree Fruit Research and Extension Center, details findings from his multi‑year effort to shed light on the European earwig and its role in combating a costly orchard pest.
“Earwigs will eat just about anything, but we've found that aphid pests are high on their menu,” Orpet said. “By dining on pests and reducing growers' need to spray insecticides, earwigs are unappreciated predators that have important benefits for agriculture.”
Shy, invasive omnivore
An invader in U.S. orchards and gardens, the European earwig was first found in Seattle in 1907, spreading across the continent soon after. With their wriggly bodies and scary‑looking tail pincers, earwigs have always suffered from a bad reputation.
“Apple pickers don't like them, because they have a tendency to hide in apple clusters,” Orpet said. “Farmers often find them inside damaged fruit, and since earwigs feed mostly at night, it's hard to see what they feed on. “Some growers wonder if they cause damage themselves.”
Scientists like Orpet, however, have long suspected that earwigs are an important predator of aphid pests.
Apple trees covered in “snow”
Orpet came to the earwig through his research into the woolly apple aphid, a costly pest of Washington's $2.4 billion apple industry.
Gaining its name from their coat of cottony fibers, woolly apple aphids feed on the roots and branches of apple trees, stealing nutrients and water and causing galls, or abnormal growths. Infestations can decrease tree growth and keep fruit from developing, while the aphid's sticky honeydew secretions can bring on fungal infections.
About the size of a sesame seed, woolly apple aphids can amass in fluffy, meter‑long colonies.
“In bad years, infestations make apple trees look like they're covered in snow,” Orpet said. “That's when growers really take notice.”
Growers have difficulty managing woolly aphids with insecticides, because there are few effective insecticides, and no organic ones, currently available. Well‑known predators like ladybugs and lacewings could take a bite out of the woolly aphid population, but Orpet wanted to know if the earwig makes a difference.
Working with Jessica Goldberger, an agricultural sociologist at WSU's Department of Crop and Soil Sciences, Orpet interviewed 15 orchardists and managers in Washington state, gauging their opinions on the insect's role.
Most growers weren't sure whether earwigs make a real difference for their crops, and some thought of them as minor pests.
At the same time, Orpet was learning what earwigs are really up to in Washington orchards. Working with managers at four different commercial orchards, Orpet set about catching earwigs with cardboard traps.
Aphids: Earwigs' favorite food
Active at night, earwigs hide by day in tight spaces. Corrugated cardboard sheets are a perfect shelter, so he could easily shake them out and count them.
Sectioning off orchards, Orpet removed earwigs in some places, adding them at others. In every site, he counted woolly aphid colonies and checked for fruit damage.
“There was an obvious difference,” Orpet said. “There were fewer aphid colonies in places where I released earwigs.” He found no evidence that earwigs were causing damage themselves, but captured video footage of earwigs eating aphids and destroying their colonies.
Orpet also inspected the contents of trapped earwigs' digestive systems to see what they actually eat. He found that earwigs regularly dine on aphids, even when local aphid populations are small.
“Our results show that earwigs aren't pests, and actually improve biological control,” Orpet said. “Some farmers spray chemicals to knock down their populations, but this research shows they don't have to, and probably shouldn't.
“Growers can reduce pesticide use, save on chemicals and labor, and leave this misunderstood predator to do its beneficial work, protecting their apples from aphids,” he added.
Along with Orpet and Goldberger, co‑authors include WSU entomology professors David Crowder and Vince Jones.
Their research was funded by the Washington Tree Fruit Research Commission, USDA's National Institute of Food and Agriculture, and the Western Sustainable Agriculture Research and Education Program.
Media contact:
- Robert Orpet, doctoral graduate, Department of Entomology, 847‑337‑4480, robert.orpet@wsu.edu
- Author: Ben Faber
If you hang around an orchard long enough something unusual will show up, especially when seasons change and there's more rain than usual and it's cold, but not so cold that it freezes and it's prolonged. So out of San Diego comes a request for an identification of a brown bump on avocado stems. It's a brown aphid. Is it something of concern? Likely not. Over the years there have been reports of several aphids on avocado. Check out Walter Ebeling's "Subtropical Fruit Pests" at Avocadosource.com:
http://www.avocadosource.com/papers/research_articles/ebelingwalter1959b.pdf
These things come and go, and they don't do any damage because once the biocontrol bugs get going, they are fresh meat for them.
- Author: Ben Faber
A local Ojai grower asks why there seems to be more citrus thrips damage to 'Pixie' mandarins this year. Was it because of the extended bloom due to warmer spring last year? The hotter summer up there that was more similar to climate in the Central Valley? Was it due to the Area-Wide Spraying for Asian Citrus Psyllid - ACP? Or is this a remnant of the Thomas Fire that dumped ash all over the county, disrupting biocontrol agents like lady bird beetles?
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=26095
And what else does fire do to citrus?
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=28315
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=26510
This is classic thrips damage. In this area, it is not usually a problem. This year it seems to be more common. It's not always clear what is the main cause of and what all the interactions are that lead up to an outbreak like this. Just that there is damage now that occurred 10 months ago.