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From the UC Blogosphere...

New Online Course Available on Pesticide Resistance

There is a new online course from UC IPM designed primarily for PCAs and licensed pesticide applicators.  This course is based on a series of pesticide resistance workshops held in Davis, Fresno, and Kearney in 2014.

The course explains how resistance has developed among fungi, insects, and weeds and how it can be managed.

2.0 "Other" CEUs are available from the Department of Pesticide Regulation.

The course contains:

 You can find this course on our web site at:

As a reminder, this course does NOT run on Internet Explorer 9 (IE9) or later versions of IE and will not accurately track your scores in those browsers. Please use IE8, Firefox, Safari, or Chrome. Sorry for any inconvenience this may cause.

Posted on Friday, October 31, 2014 at 7:29 AM

Scientists search for an odor Asian citrus psyllids cannot resist

New chemical attractants could make a better Asian citrus psyllid trap.
UC Agriculture and Natural Resources scientists based at UC Riverside are honing in on odors that might lure Asian citrus psyllids into traps, and other odors that will keep them away from citrus trees, reported Mark Muckenfuss in the Riverside Press-Enterprise.

Anandasankar Ray, professor in the Department of Entomology at UCR, along with two other researchers, published results recently that Ray believes are promising enough they may soon be adapted for grower use.

Ray and his team tested three attractant odors in El Monte backyards using yellow sticky traps. More than twice the number of psyllids were found in the scented traps compared to unscented traps, the article said. In time the researchers will also test chemicals that can mask odors that are pleasant to Asian citrus psyllids and some that repel the insects.

Other research projects underway at UC Riverside to combat Asian citrus psyllid and the disease it can spread were also noted in the Press-Enterprise article. They are: biological controls, including a tiny wasp imported from Pakistan that feeds on the psyllids; insecticides; developing resistant strains of citrus trees; finding a way to kill the bacteria spread by psyllids once it is in the tree; and discovering ways to identify diseased trees earlier.

Posted on Thursday, October 30, 2014 at 2:19 PM

My Favorite Bee: The Carpenter Bee

First, I want to say that I have never had an infestation of carpenter bees. I just enjoy seeing them in my front yard. If my home or any of my fences were suffering from an infestation of carpenter bees, I might have to rescind this post. If you think you might have an infestation of carpenter bees, please check out this link.

I think most, if not all, home gardeners have heard about the plight of the honeybees in the past few years. But did you know that there are most than 25,000 species of bees around the world? The United States is home to about 4,000 species. Both honey bees and bumble bees (family Apidae) are what are called "social" bees - meaning that they create colonies (hives) and work as a team. I was surprised to learn during my training to become a Contra Costa County Master Gardener that most native bees are solitary bees - I did not know that any bees were solitary! Carpenter bees fall into this category - a solitary bee.


Just because carpenter bees are solitary and do not belong to a colony does not mean that they are not good pollinators. The carpenter bees that I see most often are buzzing around my front yard - specifically around the Hot Lips Sage that grows in the front corner of my front yard

Now, you might wonder, why are these bees called carpenter bees?They make their nests in old wood - in fence posts and eaves most commonly in developed areas. Digger bees are similar in appearance and size to carpenter bees, and they make their nests in bare soil.

I do not know why, but I have always enjoyed seeing one or two of these big, black beauties buzzing around my yard. In researching for this post I learned that male carpenter bees, which are the solid black ones I see most often, cannot sting. So yes, I enjoy them even more now! So keep you eyes open, and the next time you see one of these beauties thank them for the solitary hard work they do in pollinating our plants!



Posted on Wednesday, October 29, 2014 at 7:00 AM

California pest invasion rate increasing

Introduction of new invasive pests into California seems to be increasing, reported Todd Fitchette in Western Farm Press. The story was based on presentations at the recent professional crop advisors convention in Anaheim by UC Cooperative Extension specialists Mark Hoddle and UC Riverside entomology professor Richard Stouthamer.

Before 1989, Hoddle said, California saw about six new pest invasions per year. The number has risen to about 10 per year, and the cost amounts to about $3 billion annually.

Asian citrus psyllid, a relatively recent invader in California, has farmers particularly worried because of the pest's ability to spread the lethal bacterial disease huanglongbing in citrus. In late 2011, Hoddle's lab began releasing a natural enemy of the psyllid he collected in the Punjab, Pakistan, a stingless wasp called Tamarixia radiata.

According to the Western Farm Press article, Hoddle is now studying a second natural enemy of ACP -  Diaphorencyrtus aligarhensis - in quarantine at UC Riverside.

Stouthamer is studying another troublesome invasive pest in California, the polyphagous shot hole borer. The pest attacks many tree species that shade California streets, landscapes and parks; their greatest threat to agricultural production appears to be in avocados.

At the meeting, Hoddle said there is a growing and vocal minority of ecologists who believe invasive species are not such a serious problem, Fitchette wrote.

“They think we should just relax and let them install themselves in the environment and do whatever they like,” Hoddle said. “I think that's a wrong viewpoint to be taking with a lot of these organisms.”

UC Cooperative Extension specialist Mark Hoddle inspects a citrus tree for insects.
Posted on Tuesday, October 28, 2014 at 9:05 AM

Daily Life For Master Gardeners

It's a Recluse?

By Andrea Peck


Spiders are sneakish creatures. They while away the time, creating great lacey homes.  Their constructions are visually delicate, yet determinedly strong.  They are unflappable, unmovable. Are they arrogant as they unapologetically flaunt the fact that they are not insects? As they drape their curtain home across your most-used pathway? Despite those leggy legs they resist running off in a tizzy when they see you. They have 8 eyes. You have been noticed. But, it is not becoming to rush off.  My dear.

Myth and mystery surround them. Misconceptions.

The brown recluse (Loxosceles reclusa) is the master of deception. It holds the gold medal for least understood arachnid, particularly here in California.   We all have a friend of a friend who has been bitten by one. We all know that the brown recluse is the worst, the most treacherous, of the spiky-limbed spider family.


Not exactly.

The brown recluse does not live in California. It does not live here. At all. It has visited on occasion, mostly through media such as boxes which have been shipped here from another state where the shady lynx is actually commonplace.  The reality is that there have been hardly a handful of incidents involving this notorious character in the last 40 years.

While most spiders have 8 eyes, set in 2 groups of 4, the brown recluse differs in this regard. It has 3 sets of eyes, two in each set (called a dyad), for a total of 6 eyes. The spider is brown with a visible violin shape on its cephalothorax, or the portion of the body where the legs attach. It's much bigger than I had ever heard described. It is as big as a quarter. Huge. Somehow I was under the impression that the vicious beast was almost microscopic.

Ninety percent of brown recluse bites are inconsequential and may even go unnoticed by the victim. Basic first aid which includes Rest, Ice, Compression and Elevation (RICE therapy) often does the trick where the bite is significant.  There are the cases where the bite does parlay into a major issue, involving necrotic tissue and/or secondary infection. These cases are those that give the little bugger its fearsome reputation and a visit to the emergency room becomes mandatory. Death, though rare, does indeed occur when the bite proves more than the victim can sustain. For the vast majority of us Californians, it is important to remember that the likelihood of being bitten on our own home turf is practically zero. If you find you have been diagnosed as having a brown recluse bite, you might consider that this is commonly misdiagnosed and that another disorder, such as Lyme disease or Staphylococcus or Streptococcus may be the real culprit. This is important to consider because experts (as in the very funny and highly informative attached link) assert that misdiagnosis is rampant.

Well, that is one spider you can cross off your list, unless, of course, you decide to visit a state where the brown recluse is so prevalent that the average homeowner runs across more spiders per hour than California does in 40 years. That is your choice, though and I'm not going to try to tell you not to visit Aunt Mabel.

I don't feel satisfied leaving spidey yet. Next week I will tackle a more potent threat that actually is alive and well in our state and county. Your job is to guess who she is.

Brown recluse spiders are established in 15 states: Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Ohio, Oklahoma, Tennessee, and Texas.

Posted on Monday, October 27, 2014 at 8:05 PM

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