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New York Times

Photo

Cherry tomatoes. Researchers found that domesticated tomatoes like these were less resistant to whiteflies than currant tomatoes, a wild species. Credit Dean Fosdick/Associated Press

Whiteflies are the scourge of many farms, damaging tomatoes, peppers, eggplants and other crops. Now, researchers in Britain report that a species of wild tomato is more resistant to the pest than its commercial counterparts.

The wild type, the currant tomato, is closely related to domestic varieties, “so we could crossbreed to introduce the resistance,” said Thomas McDaniel, a biologist and doctoral student at Newcastle University in England and a co-author of the study, published in the journal Agronomy for Sustainable Development. “Another method would be genetic engineering, if we identified the genes.”

The researchers studied Trialeurodes vaporariorum, a species of whitefly that often attacks tomatoes grown in greenhouses. Whiteflies damage tomato plants by extracting the plant’s sap, which contains vital nutrients; by leaving a sticky substance on the plant’s surface that attracts mold; and by transmitting viruses through their saliva.

But currant tomatoes have some sort of mechanism, yet to be understood, that repels whiteflies. “They seemed to move away every time they tried to sample the sap,” Mr. McDaniel said.

The wild plants also produce a chemical reaction that causes the plant sap to gum up the whitefly’s feeding tube.

Growers use a parasitic wasp to control whiteflies. The wasp lays its eggs on young whiteflies, which are eaten by hatching larvae. The treatment is expensive and laborious. As an alternative, farmers use chemical pesticides, but some have been linked to declines in bee populations.

“Genetic diversity is very, very low in domestic crops, so introducing these genes that we’ve lost along the way is probably quite important,” Mr. McDaniel said.

Continue reading the main story

 

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California eradicates the European grapevine moth

Pest first discovered in Napa vineyard in 2009
  • Trap counts quickly surpassed 1,000 in Napa County alone
  • Pest eventually spread to other grape growing regions in California

California agriculture officials report the European grapevine moth (pictured) has been eradicated.

 

In what’s being heralded a  “success story,” California is officially eradicated of the European grapevine moth (EGVM).

The good news means the lifting of quarantine restrictions in several grape-growing regions throughout the state.

The EGVM was first detected in a Napa County Chardonnay vineyard in 2009, the first time ever the pest was discovered in North America. Subsequent detections in the counties of Fresno, Mendocino, Merced, Nevada, Santa Clara, Santa Cruz, San Joaquin, Solano and Sonoma led to quarantine restrictions and a mass effort to determine pest numbers through trapping.

The last EGVM detection in California was June, 2014.

How the EGVM first wound up in Napa County remains a mystery.

“It is no easy feat to eradicate an invasive species, especially one like the European grapevine moth when it gains a foothold in a place as hospitable as California’s prime wine grape growing region,” said Karen Ross, Secretary of the California Department of Food and Agriculture.

Napa Valley wine grape grower Steven Moulds calls the eradication “a hard-fought victory.”

EGVM numbers quickly rose, particularly in Napa County, where trap counts in 2010 exceeded 100,000 moths from 3,800 traps blanketing the county. Quick collaboration between local agricultural officials, state and federal government agencies, and a group of international researchers including University of California wine grape specialists, helped identify the problem and recommend a course of action leading to eradication.

The EGVM, or Lobesia botrana, originates from southern Europe.

First and second generation insects feed on grape flowers and developing berries. By the third generation, larvae can cause great damage by feeding on grape berries, contaminating the fruit and exposing it to Botrytis and other infections.

Over the years, growers in the San Joaquin Valley and elsewhere outside of the Napa and Sonoma wine regions were able to quickly eliminate moth counts. As this happened, quarantines covering 2,334 square miles in 2013 fell to 446 square miles in 2014.

The Napa wine region took a mating disruption approach to eradication, while those in the San Joaquin Valley took a more direct approach by using labeled insecticides to kill the insect.

Napa County Agricultural Commissioner Greg Clark credits the collaborative effort between all parties involved, from local growers and staff in his office, to local and international university researchers, to the state and federal government, with the success achieved.

At the end of the day, Clark says the success of the eradication efforts needs to be pinned on local efforts.

“Eradication of the EGVM is an important accomplishment in itself, but this program is perhaps even more valuable as an example of what we are capable of as a community,” Clark said.

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Reprinted from PestNet

This article is obviously a promotion by the company Biobet, but it might be of interest to members nevertheless. We are putting it out as leafminers can be a serious pest, and there maybe members interested in these Diglyphus wasps

Obviously, this comes with no endorsement by Pestnet which has no involvement in the company or the report.

There are other companies that sell these wasps

FreshPlaza
http://www.freshplaza.com/article/161430/Complete-leafminer-control-strategy-available-for-tomatoes

Complete leafminer control strategy available for tomatoes

Biocontrol options to control leafminer include two well-known natural enemies Diglyphus isaea and Dacnusa sibirica. “Biobest ’s UK team has developed valuable experience in tomato on how to use these two parasitic wasps in a robust combination strategy. As leafminer pressure increases in tomato crops in the Netherlands, France and other Western European countries, more growers are adopting this highly effective control strategy, taking advantage of Biobest’s advice and broad product offering” says Biobest’s Product Manager for Macrobials, Yann Jacques.

Several species of Lyriomyza genus occur in commercial crops: most importantly the tomato leafminer (Lyriomyza bryoniae), the serpentine leafminer (L. trifolii) and the pea leafminer (L. huidobrensis). Leafminer has become a serious pest in European tomatoes. The main issue is the damage done by larvae tunneling through the leaf. These mines reduce the plants’ photosynthetic capabilities, slow down the production of flowers and ultimately affect fruit yield. Leafminer is particularly damaging for sweet tomato varieties where it develops faster.

Phil Walker, General Manager of Biobest UK: ”In UK tomato crops we have developed quite some expertise using a combination of two complementary parasitic wasps – Diglyphus isaea and Dacnusa sibirica. We were able to develop robust strategies, capitalizing on the complementarity between the biological characteristics of these two parasitic wasps.”

Yann Jacques explains: “Effective early in the season, Dacnusa comes in first to manage and slow down the pest build up. To identify when to start introductions we recommend yellow Bug-Scan sticky traps to detect adults, plus regular inspection of the crop to look for the tell-tale stings.”

Dacnusa has a very high search capacity and, hence, can already establish at very low pest densities. Dacnusa is an endoparasite. It lays eggs directly in leafminer larvae tunneling through the leaf. Dacnusa females looking to oviposit distinguish non-parasitised from parasitised leafminer larvae. Dacnusa is very well adapted to early season conditions, less to conditions prevailing later in the season or in the south. That is where Diglyphus has complementary strengths.

Diglyphus, explains Yann, is an ecto-parasite. “The female punctures a leafminer larva to paralyse it, before depositing an egg next to it. Diglyphus not only parasitizes leafminer larvae, it also host feeds on young larvae. Capable of fast population build up, this wasp can rapidly gain control of a rising leafminer population.”

For more information, please visit www.biobestgroup.com.

Publication date: 8/1/2016

Grahame Jackson
24 Alt street
Queens Park
NSW 2022
Australia

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Farm Press Blog

It was interesting to read the commentary from my colleague Hembree Brandon quoting Mike McCormick, president of the Mississippi Farm Bureau Federation, on the impact of the boll weevil.

That’s because my family has its own boll weevil story. In 1926, my grandfather left St. Francis County, Ark., and moved 50 miles north to get away from the pest. No one knew how to control it, and it was literally eating them out of house and home.

They returned two years later after someone determined they could kill the boll weevil by spraying or “dusting” with insecticides such as calcium arsenate, also known as Black Annie.

McCormick’s comments about the dispersal of families in his part of Mississippi due to the pest came at a meeting of the Mississippi Boll Weevil Management Corporation and Farm Bureau Cotton Policy Committee where they celebrated another weevil-free year.

 

Those familiar with the industry know cotton farmers raised millions of dollars and coupled that with government funding to eradicate the boll weevil from all but the southernmost part of the Cotton Belt.  (It’s too bad we can’t build a wall to keep the boll weevil south of the border.)

The irony is that if the boll weevil was as prevalent today as it was in the 1980s, there’s no guarantee cotton producers and entomologists could eradicate the pest.

For openers, the political will needed to unite all the disparate elements of agriculture and government to fund such a program may no longer exist. And there’s the possibility malathion, the insecticide that was the workhorse of the boll weevil eradication effort, would not be available to complete it.

EPA is currently conducting a review of several organophosphate insecticides, including chlorpyrifos (Lorsban). There are concerns the use of EPA’s “water model” to determine the impact of chlorpyrifos rather than real-world scientific data could spill over into reviews of other OPs such as malathion.

Public health officials are worried about the latter because malathion is used extensively in mosquito abatement programs. Canceling the registration for a product that could be critical to battling the Zika virus would be a significant loss to fearmongering by environmental activists.

For more information on cotton issues, visit www.cotton.org.

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Food security is an issue of major concern with climate change, as water supplies become scarce and the world’s population continues to grow.

Combined, these factors are expected to stress the world’s agricultural capacity. But one solution may be right underfoot, so to speak. Insects are easy to digest and grow. They may even provide global food security in the future. But while human beings have eaten them for thousands of years—and two billion people still include bugs in their daily diet—for many, there’s a “yuck” factor to contend with. UCLA professor Andy Rice explored the delights of entomophagy (bug eating) with L.A. Laker Metta World Peace and students in his “Food: A Lens on Environment and Sustainability” class. Many first-timers were dubious about partaking in fresh roasted crickets, with reactions varying from the purely squeamish “like salty regret in my mouth” to “it’s like eating shrimp.” For his part, Metta described his first roasted cricket as “not bad, tastes like an end piece of bacon, crispy… and a little bit scary.”Despite such mixed reactions, Rice believes bugs will be a great source of protein in a world affected by climate change. Many experts believe that global warming and human development will reduce agricultural lands. Insects could be a smart alternative to resource-intensive foods such as beef. They are hardy and thrive in warmer temperatures, which are expected to be stressors for traditional livestock. The infrastructure for insects is also simpler and requires less space, making it easy for families to raise certain species at home. Watch and learn…

 


The video was made by Dr. D. Andy Rice, ASPIRE Fellow in Socially Engaged Media in Undergraduate Education Initiatives and co-instructor for the freshman cluster “Food: A Lens on Environment and Sustainability,” in collaboration with the freshmen enrolled in the 2015-16 class. The Healthy Campus Initiative also provided funding and support for the project.

 

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2010-2015: Impact of bagrada bug on desert cole crops

  • PCAs have adopted effective management programs to protect seedling crops from the bagrada bug during stand establishment.
  • Insecticide usage to control this pest remains high, and the percentage of acreage treated in 2015 was consistent with previous years.

With the 2015-2016 winter produce season finally finished, now is a good time to reflect on pest issues last fall.

The bagrada bug, Bagrada hilaris, first occurred on desert cole crops at damaging levels in Fall 2010 and has since been an established pest.

In an attempt to document the severity of bagrada bug infestations on direct seeded and transplanted cole crops, and the intensity of chemical management, we have annually surveyed growers and pest control advisers from Yuma, Imperial, and Maricopa counties since 2010.

We recently conducted our annual survey in April.

 

Last fall was the lightest year we’ve seen to date. Based on seasonal population abundance studies of adults infesting non-treated broccoli plants at the Yuma Agricultural Center, bagrada bug infestations were lower than what we had observed since the pest first showed up in the desert.

Estimates of stand losses from bagrada bug infestations at stand establishment in both direct seeded and transplanted crops have decreased by more than 50 percent over the last five years. The lower losses reported last fall were likely due to the lighter bagrada pressure experienced last season.

Plant injury, defined as plants with multiple heads, forked terminals, and/or blind terminals resulting from bagrada feeding, was also lower in 2015 compared to previous years.

These data suggest that PCAs have adopted effective management programs to protect seedling crops during stand establishment. Insecticide usage to control this pest remains high, and the percentage of acreage treated in 2015 was consistent with previous years.

Pyrethroids remain the primary product used to control bagrada bug adults either via chemigation or with foliar spray applications. Based on survey results, products that have contact activity appeared to provide the most effective control against bagrada adults on both direct seeded and transplanted cole crops.

However, more neonicotinoid products (Venom) are beginning to be implemented into PCA’s IPM programs.

Overall, the results of the PCA survey are consistent with results obtained in research trials conducted at the Yuma Agricultural Center over the past four years.

A summary of the 2010-2015 survey results can be found in this report – Impact of Bagrada Bug on Desert Cole Crops, 2010-2015.

Note: This article is from the May 25, 2016 issue of the University of Arizona’s “Vegetable IPM Updates’ e-newsletter and is reprinted with permission from Dr. Palumbo. 

Latest news in western agriculture – Western Farm Press Daily e-news blast – delivered free to your inbox.

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UF/IFAS Expert: Whitefly Species Likely to Cause Growers’ Problems

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Newswise — GAINESVILLE, Fla. — A University of Florida Institute of Food and Agricultural Sciences expert predicts the Q-biotype whitefly discovered in April in Palm Beach County will likely cause problems for growers.

The Q-biotype whitefly – not to be confused with the B-biotype, which came to Florida in the mid-1980s – is now being seen outside greenhouses and nurseries and poses a threat to ornamental plants and agricultural crops. After the B-biotype was found in Florida in the 1980s, scientists saw big increases in the diversity and frequency of whitefly-transmitted viruses in many Florida crops, said Jane Polston, a UF/IFAS plant pathology professor. Crops like beans, tomato, watermelon and squash were hit hard by these viruses after the appearance of the B biotype.

“This Q-biotype is a pest that damages crops and resists many of the insecticides that are effective on the B-biotype, the whitefly that is common in many ornamental and vegetable crops,” Polston said. “And like other whiteflies, it is capable of transmitting viruses from one plant to another.”

But because the Q-biotype whitefly feeds for longer periods on some plants, it has a greater chance of acquiring a plant virus, Polston said. The more time a whitefly spends feeding on a plant, the more likely it is to acquire a virus from an infected plant. Only a few studies have been conducted on the host plants that Q and B feed on, but those few studies indicate that Q and B do have different preferences, she said.

Because these whitefly species feed differently, vegetable and ornamental crop growers may see different viruses in their crops, as well as how many plants become infected each season, Polston said.

“And because it’s harder to manage with pesticides, we may see higher populations of this new whitefly, and that can mean high numbers of virus-infected plants,” Polston said.

Viruses may show up in plants that were not infected before, Polston said. Scientists and Extension faculty also should be prepared to see changes in the percentage of infected plants on farms, she said.

In other words, the Q-biotype whitefly is not simply an insect management issue; the insect also transmits viruses, she said.

This whitefly can transmit many different plant viruses, such as Tomato yellow leaf curl virus, Squash vein yellowing virus, Tomato infectious chlorosis virus, Cowpea mild mottle virus, and many others, according to a 2013 paper that Polston co-wrote.

Known scientifically as Bemisia tabaci, the Q-biotype or Mediterranean whitefly is a light-colored, flying insect slightly less than 1 millimeter in length.

When the whitefly was reported this spring, it marked the first time the Q-biotype of Bemisia tabaci had been found outside a greenhouse or nursery in the United States since it was found on an ornamental plant in a greenhouse in 2004-2005, said Lance Osborne, a UF/IFAS entomology professor.

Researchers with UF/IFAS are working with the U.S. Department of Agriculture, Agricultural Research Service and the Florida Department of Agriculture and Consumer Services to manage the whitefly.

Here are some helpful hints regarding the Q-biotype whitefly:
The following measures are recommended to control the spread of Q-biotype whitefly:

• Homeowners who suspect they have a whitefly infestation should contact their UF/IFAS Extension county office. Office locations may be found at http://www.bit.ly/1Q8wguw.

• For identification purposes, infested leaves and dead insect specimens should be brought to local Extension offices. Wrap in a dry paper towel and place in a seal-able plastic bag and then in an envelope. Freezing the specimen overnight before transport is highly recommended. Live insects should not be transported.

• The collection information should be included with the sample. Date, location, what type of vegetation is affected, number of suspected whiteflies, and any information about whether a pesticide has been used on the plant, is helpful information to managing the pest. For steps on how to submit a sample to FDACS DPI, visit http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Business-Services/Submit-a-Sample-for-Identification.

• Because new populations have built up resistance to chemicals, it is recommended that suspected whitefly infestations be confirmed before chemically treating the insects, as it may be needless to spray pesticides.

• Landscapers and pest control operators should inspect for signs of whitefly pests, communicate with neighboring properties and homeowners associations, employ good management and growing practices, and implement whitefly management guidelines available at http://www.mrec.ifas.ufl.edu/lso/bemisia/bemisia.htm.

• Nurseries that suspect whitefly infestations should contact the FDACS Division of Plant Industry at 1-888-397-1517.
• Here are some helpful links about the issue:
http://www.bit.ly/1WD6CmM, http://www.bit.ly/1Tm5iBm and http://www.bit.ly/1XxxG6D
• The Whitefly management plan for Growers: http://www.mrec.ifas.ufl.edu/lso/bemisia/DOCUMENTS/WhiteflyManagementProgram_1-15-15.pdf
• The list of materials for landscapers:
http://www.mrec.ifas.ufl.edu/lso/bemisia/DOCUMENTS/LANDSCAPE-Active-Ingredients.pdf.

-30-
By: Brad Buck, 352-294-3303, bradbuck@ufl.edu
Source: Jane Polston, 352-273-4627, jep@ufl.edu

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