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Summer heat is supressing 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

Precipitation and wildfire impacted by climate change

A new study out of UC Riverside projects an increase in rain and snow in California due to climate change, reported Matt Smith on Seeker.com. Anthropogenic impacts on climate are expected to produce a chronic El Niño-like weather pattern off the Pacific coast of the U.S., leading to about 12 percent more rain and snow by 2100.

The study used a newer computer model and relied on other models that have a better record of simulating precipitation and the effects of an El Niño on the state. El Niño, the cyclical warming of the Pacific Ocean near Earth's equator, typically produces warmer temperatures across much of the United States and more rainfall over California.

More rain and fire predicted for California due to climate change.

Meanwhile, an article by Joshua Emerson Smith in the San Diego Union-Tribune presented less-welcome climate change news. It concluded that wildfires are expected to get longer and more intense in California due to climate change.

“We will need some very new approaches to deal with both the increasing hazard of fire and our increasing exposure to it,” said Max Moritz, UC Cooperative Extension specialist in fire ecology and management at UC Berkeley's College of Natural Resources. “The situation we have created is dangerous, and without a major shift in perspective it will only get worse.”

There are ways to limit the ignition of the wildfires. The article said about 95 percent of all wildfires are caused by people, so it's important to be aware of fire-safe practices pertaining to home maintenance, campfires, target shooting, vehicle use and other outdoor activities. 

Here are a few examples of fire-safe best practices:

  • Mow lawns in the morning before it gets too hot. Never mow when it is windy or extremely dry. Avoid rocks when mowing; metal blades can cause sparks when they hit rocks.
  • Don't drive a vehicle on dry grass or brush. Don't allow vehicle brakes to wear thin, as thin brakes can cause sparks. Carry a fire extinguisher in the car.
  • Maintain 100 feet of defensible space around homes in fire-prone areas. UC ANR experts recommend a five-foot zone immediately adjacent to the home be completely devoid of plants and anything combustible.

 

Posted on Friday, July 14, 2017 at 10:16 AM
Tags: climate change (37), Max Moritz (14), rain (6), wildfire (70)

South American palm weevil stars in a Hollywood horror film

One of Los Angeles' quintessential icons - palm trees - are being threatened by an invasive pest from overseas - the South American palm weevil. KQED Science produced a clever overview on the life and times of this devastating pest, punctuating it with a surprise ending that features UC Cooperative Extension specialist Mark Hoddle

The story outlines the pest's life cycle, which starts when a female lays its eggs in the crown of a palm. They hatch and larvae eat the plant from the inside out, eventually killing the palm. The larvae pupate, complete metamorphosis, then fly off to find another palm to attack.

Hoddle conducted an experiment to determine how far the weevils can fly. He glued the pest on a sort of insect treadmill and let it fly in circles. He found that they can travel up to 15 miles a day, enough to easily hopscotch from palm to palm on their own and spread widely.

The biocontrol scientist demonstrates one way to get rid of South American palm weevils. If you're not squeamish you can view the video on the KQED website.

South American palm weevil adult. (Photo: Center for Invasive Species Research)
Posted on Tuesday, June 20, 2017 at 2:41 PM

Great Plains' wildfires have tripled since 1985

Wildfires used to be rare in the Great Plains, but that is no longer the case. A new study shows the average number of large fires grew from about 33 per year in 1985 to 117 per year in 2014, reported Chris Mooney in the Washington Post.

The study's lead author, Victoria Donovan of the University of Nebraska, Lincoln, said the increasing number of wildfires is consistent with climate change and an incursion of more invasive plant species that could be providing fuel.

UC Cooperative Extension specialist Max Moritz said the study's results align with his observations. However, he added that he suspects that they reflect not so much human-caused climate change, but rather, changing human behavior. Humans have been found to be overwhelmingly responsible for lighting U.S. wildfires over the past 20 years, according to research he cited. But these facts should not downplay the importance of dealing with anthropogenic climate change.

"It does highlight the importance of human ignitions and where/how we build our communities on the landscape," Moritz said. "Wildfire is not going away anytime soon. We must learn, as a society, to coexist with wildfire."

 

The Great Plains in Nebraska, where wildfire is striking more frequently. (Photo: Wikimedia Commons)
Posted on Monday, June 19, 2017 at 1:32 PM
Tags: Max Moritz (14), wildfire (70)

Salmonella infections resulting from backyard chickens

The Centers for Disease Control and Prevention is investigating a surge in human Salmonella infections linked to contact with live backyard poultry, reported Macy Jenkins on CBS Sacramento News.

The story included interviews with several chicken owners. One small girl said she loves to cuddle her chickens because "They're so cute." The owner of three specialty chickens said he allows the animals to "sleep inside with me in my bed." Both of those practices run counter to guidelines set by the CDC.

Jenkins spoke to UC Cooperative Extension specialist Maurice Pitesky, who said poultry owners should never let the birds inside of the house. His reason: "Always assume that any bird is a Salmonella carrier."

To prevent Salmonella infection, the CDC recommends:

  • Always wash hands thoroughly with soap and water right after touching live poultry and anything in the area where the live and roam.
  • Never allow poultry in the house, especially not in bathrooms and kitchen.
  • Do not snuggle or kiss the birds.
  • Stay outdoors when cleaning poultry equipment, such as cages, feed or water containers.

Read more on the CDC website.

The most common symptoms of Salmonella infection are diarrhea, fever and abdominal cramps. The illness usually last 4 to 7 days, and most people recover without treatment. 

Posted on Monday, June 5, 2017 at 2:48 PM
Tags: chickens (7), Maurice Pitesky (3), Salmonella (6)

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