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Posts Tagged: stink bug

Let's Hear It for Biocontrol, Integrated Pest Management

An assassin bug drills a pest, a spotted cucumber beetle. (Photo by Kathy Keatley Garvey)

Let's hear it for biocontrol. You've seen lady beetles, aka ladybugs, preying on aphids. But have you seen an assassin bug attack a spotted...

An assassin bug drills a pest, a spotted cucumber beetle. (Photo by Kathy Keatley Garvey)
An assassin bug drills a pest, a spotted cucumber beetle. (Photo by Kathy Keatley Garvey)

An assassin bug drills a pest, a spotted cucumber beetle. (Photo by Kathy Keatley Garvey)

A lady beetle, aka ladybug, snares an aphid. (Photo by Kathy Keatley Garvey)
A lady beetle, aka ladybug, snares an aphid. (Photo by Kathy Keatley Garvey)

A lady beetle, aka ladybug, snares an aphid. (Photo by Kathy Keatley Garvey)

A crab spider munches on a stink bug. (Photo by Kathy Keatley Garvey)
A crab spider munches on a stink bug. (Photo by Kathy Keatley Garvey)

A crab spider munches on a stink bug. (Photo by Kathy Keatley Garvey)

A great blue heron engages in a little pest management: it catches a rodent, a meadow vole, at Bodega Bay. (Photo by Kathy Keatley Garvey)
A great blue heron engages in a little pest management: it catches a rodent, a meadow vole, at Bodega Bay. (Photo by Kathy Keatley Garvey)

A great blue heron engages in a little pest management: it catches a rodent, a meadow vole, at Bodega Bay. (Photo by Kathy Keatley Garvey)

The great blue heron gets its prey, a meadow vole, in position before swallowing it whole. (Photo by Kathy Keatley Garvey)
The great blue heron gets its prey, a meadow vole, in position before swallowing it whole. (Photo by Kathy Keatley Garvey)

The great blue heron gets its prey, a meadow vole, in position before swallowing it whole. (Photo by Kathy Keatley Garvey)

Posted on Friday, August 23, 2019 at 3:37 PM
Focus Area Tags: Agriculture, Environment, Food, Innovation, Pest Management, Yard & Garden

UCCE advisor addresses severe brown marmorated stink bug damage in Turlock orchard

Last May, a Turlock almond grower noticed nearly all the nuts on a row of trees in his orchard had fallen to the ground.

“It looked like we shook this row,” he said. “I was scared. I thought the whole orchard was going to go.”

He called UC Cooperative Extension.

UCCE Integrated Pest Management advisor Jhalendra Rijal addresses farmers, pest control advisers and UC Master Gardener volunteers in a Turlock almond orchard. (Photo: Michael Rosenblum, UCCE Stanislaus County)

UCCE Integrated Pest Management advisor Jhalendra Rijal, who serves Stanislaus, San Joaquin and Merced counties, determined the cause was an infestation of brown marmorated stink bug (BMSB), an invasive pest from Asia. For years, BMSB had only been found in urban areas of California – most notably a 2013 infestation in midtown Sacramento.

With few natural predators and a wide host range – including apples, pears, cherries, corn, tomatoes, grapes and a variety of landscape trees – the population eventually moved into agricultural areas, first appearing in crops in 2016 in Stanislaus County. Rijal has been doing BMSB research since then.

Rijal set up a microscope with an oversized monitor in the field to show participants insect details.

Rijal hosted a gathering of farmers and pest control advisers Aug. 13, 2019, in the Turlock almond orchard to give them a first-hand view of the pest and the problems it causes.

BMSB are hard to find in orchards. They lay greenish colored eggs on the underside of leaves, typically in a cluster of 28 eggs. The majority of damage is caused by adults, which sting the hull with a needle-like mouth part to get to the nut. The sting can even penetrate the almond's hard shell when the fruit is mature.

This photo of the BMSB's underside shows the long, needle-like mouth part.

Globs of clear sticky sap appear on the damaged almond hulls, typically indicating nut loss inside. Early season (March-April) infestation leads to the most severe yield loss when the nuts drop to the ground. The best way to confirm the damage is caused by BMSB is to use a trap.

“I recommend growers and pest control advisors put BMSB traps in orchard edges if they suspect BMSB damage or if the orchard is located near potential overwintering structures or host crops,” Rijal said. “BMSB are good flyers and active throughout the season, damaging nuts from April through the fall. But the most substantial damage happens in the spring through early summer."

A sticky trap in the Turlock almond orchard contains a BMSB near the middle of the right side. The trap is placed next to trees, not in them, four feet off the ground. A commercial BMSB pheromone lure attracts the pest into the monitoring trap.

If the orchard is close to BMSB-favored host plants, more damage is seen. A particularly troublesome neighbor plant is tree-of-heaven.

“Tree-of-heaven is a magnet for BMSB,” Rijal said, pointing to an abandoned farmhouse site on an adjacent property. “Tree-of-heaven has a nice fruiting structure that can support a lot of BMSB.”

Adjacent to the BMSB-infested almond orchard, an abandoned home site is surrounded by an unmanaged grove of tree-of-heaven, an invasive plant from Asia that is attractive to BMSB.

Also an Asia native, tree-of-heaven was brought to California by Chinese immigrants during the Gold Rush. The roots, leaves and bark are used in traditional Chinese medicine. But its rapid growth and ability to clone itself to develop thick groves make it a noxious weed.

BMSB isn't a serious pest in its homeland because it is controlled by a natural enemy. Charles Pickett, the California Department of Food and Agriculture biological control scientist, shared a mounted sample of a Samurai wasp from Asia, Trissolcas japonicus, which lays its eggs in BMSB eggs.

“The parasite attacks most of the eggs in the field in eastern Asia,” Pickett said. “It's our goal to release the wasp in California. We first need a special permit to make sure it won't harm our environment and doesn't attack any beneficial stink bugs.”

The Samurai wasp has already found its own way to some BMSB infestation sites in the Eastern U.S. and in Los Angeles.

“We hope to someday release the parasitic wasp,” Pickett said. “It won't eradicate BMSB, but it will help.”

An insect display enables field day participants to compare insects commonly found in orchards. BMSB males and females are in the center.
 
A 2013 photo shows a tree in midtown Sacramento where BMSB aggregated. Established populations have been found in residential areas of 16 California counties from Butte and Glenn counties in the north to Fresno in the south. A population has also been found in Siskiyou County.
 
In the one-minute video below, Rijal explains the scope of BMSB infestation in California:

Posted on Monday, August 19, 2019 at 8:28 AM
Focus Area Tags: Pest Management

Summer heat is suppressing brown marmorated stink bug

The sweltering summer of 2017 has a silver lining. When the temperature rises above 104, brown marmorated stink bug population growth is significantly slowed, reported Debbie Arrington in the Sacramento Bee.

An invasive pest from Asia, brown marmorated stink bugs showed up in midtown Sacramento in 2013. Their spread to commercial crops has been a concern. The stink bugs feed on dozens of California crops, including apples, pears, cherries, peaches, melons, corn, tomatoes, berries and grapes, said Chuck Ingels, UC Cooperative Extension advisor in Sacramento County. Feeding on fruit creates pock marks and distortions that make the fruit unmarketable. In grapes, berries collapse and rot increases.

In 2014 and 2015, the bugs' numbers continued to rise. In early 2016, Ingels feared a population explosion, but a heat wave in July, with seven days at 100 degrees or higher, plus two days at 104, wiped them out.

“This year, BMSB started off at historic lows (since 2013),” Ingels said. “Then, the June heat wave hit and the population that was there plummeted. Most of our trap counts for the last few weeks have been at or near zero, whereas there's usually a peak in June. So, it seems to be proof that temperatures over 100 for extended periods reduces the population – probably especially eggs and nymphs."

Ingels and UC Davis entomologists are studying the connection between high heat and stink bugs in the lab, where the pest is exposed to extreme temperatures. One hour at 113 degrees killed all the bugs, but mortality was also high over 104 degrees.

Brown marmorated stink bugs aggregate on a midtown Sacramento tree.
Posted on Monday, July 24, 2017 at 10:43 AM

Please Eat a Stink Bug!

A praying mantis at the Bohart Museum of Entomology, UC Davis, dines on a stink bug. (Photo by Kathy Keatley Garvey)

Oh, if we could just engage in some menu planning and preparation! How often have you thought of that after watching praying mantids dine on honey...

A praying mantis at the Bohart Museum of Entomology, UC Davis, dines on a stink bug. (Photo by Kathy Keatley Garvey)
A praying mantis at the Bohart Museum of Entomology, UC Davis, dines on a stink bug. (Photo by Kathy Keatley Garvey)

A praying mantis at the Bohart Museum of Entomology, UC Davis, dines on a stink bug. (Photo by Kathy Keatley Garvey)

UC Davis entomology graduate student Charlotte Herbert, who is seeking her doctorate, takes a selfie with a praying mantis eating a stink bug. (Photo by Kathy Keatley Garvey)
UC Davis entomology graduate student Charlotte Herbert, who is seeking her doctorate, takes a selfie with a praying mantis eating a stink bug. (Photo by Kathy Keatley Garvey)

UC Davis entomology graduate student Charlotte Herbert, who is seeking her doctorate, takes a selfie with a praying mantis eating a stink bug. (Photo by Kathy Keatley Garvey)

Posted on Wednesday, November 23, 2016 at 5:26 PM

UC and CDFA researchers make progress in fight against exotic brown marmorated stink bugs

Brown marmorated stink bugs (Photo: USDA)
Scientists are rearing tiny Asian wasps in quarantine and evaluating whether they can be released in California to battle brown marmorated stink bug (BMSB), an invasive pest that poses a serious threat to the state's $54 billion agricultural industry, they reported in the current issue of California Agriculture journal.

The wasp, Trissolcus japonicus, has scientists feeling hopeful, said Chuck Ingels, UC Cooperative Extension advisor in Sacramento County and one of the 10 authors of the article. Ingels and a team of UC and California Department of Food and Agriculture scientists have been closely monitoring BMSB since large populations were found in downtown Sacramento in 2013.

“We hope T. japonicus will render BMSB a much lower threat, to where it might end up a background stinkbug,” Ingels said. “It all depends on how well the parasitoid adapts to our climate if we get to the point of releasing it.”

At the moment, BMSB has not caused significant damage to agricultural crops in California, but UC scientists want to be ready with solutions should it migrate into farms. BMSB – a native of China, Korea, Japan and Taiwan – made its way to the East Coast of the U.S. in the 1990s. By 2010, it caused millions of dollars in crop damages in apples, peaches and vegetables. The pest was first detected in California in 2002. It is now in urban communities in Siskiyou, Butte, Sutter, Yolo, Sacramento, San Joaquin, Stanislaus, Santa Clara and Los Angeles counties.

In urban areas, the pest is a nuisance. Bugs aggregate in late summer on walls and trees, and then seek refuge in the winter inside homes, garages and other buildings. Massive aggregations of BMSB are a disturbing sight and emit a pungent cilantro-like odor. In restaurants, BMSB can alarm patrons when the insects are mistaken for cockroaches, potentially hurting the eatery's bottom line.

“Apartment managers complain that tenants are threatening to move out because of the stink bugs,” Ingels said. “It's an economic issue.”

But BMSB's potential for damage in commercial agricultural crops portends a much greater economic threat. BMSB's host plant range of 170 species includes many valuable fruit, nut, vegetable and ornamental crops. In August and September of 2015, BMSB was found feeding on citrus, persimmons and apples in a Sacramento community garden. In July 2015, BMSB was found for the first time in traps placed close to citrus, kiwi and avocados in Los Angeles County backyards.

Already, several “generalist predators” have been observed feeding on BMSB – such as lacewings, mantids, earwigs, lady beetles, assassin bugs, pirate bugs, big-eyed bugs and spiders. Field research has also found that at least 12 North American species of stink bug egg parasites will lay eggs in BMSB egg masses.

A Trissolcus japonicus female readily parasitizes eggs of BMSB. (Photo: Jesus "Ricky" Lara)
However, because the local species may not be enough to provide adequate levels of population suppression, the researchers are interested in T. japonicus, a natural enemy of BMSB in its home range in China. The wasp can help to control populations of BMSB by laying its own eggs inside BMSB eggs. The researchers say finding and establishing a host-specific natural enemy may significantly increase control and prevent further economic problems.

“The introduction of a beneficial natural enemy like T. japonicus, which co-evolved with BMSB in China, increases our chances of successfully targeting and suppressing BMSB populations in the United States,” said Ricky Lara, a post-doctoral scholar at UC Riverside and lead author of the article. “In California, UC and CDFA researchers will continue to conduct the required safety evaluations with T. japonicus to deliver a cost-effective BMSB biological control program.”

Without being introduced by authorities, T. japonicus have been found in Maryland, Virginia and Vancouver, Wash., presumably having been accidentally introduced via parasitized BMSB eggs from Asia. DNA analyses determined that the T. japonicus collected in the field did not originate from the populations in quarantine, indicating that there have been no accidental escapes from these secure facilities.

The California research was funded with a grant from the CDFA Specialty Crop Block Grant Program, which was awarded to Charles Pickett, CDFA senior environmental scientist specializing in biological control, and Mark Hoddle, UC Cooperative Extension biological control specialist. Funding was also provided by the USDA Farm Bill, the California Pistachio Research Board, the Pear Pest Management Research Fund and the Consolidated Central Valley Table Grape Pest and Disease Control District.

Posted on Monday, February 29, 2016 at 8:49 AM

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