Division of Agriculture and Natural Resources
Division of Agriculture and Natural Resources
Division of Agriculture and Natural Resources
University of California
Division of Agriculture and Natural Resources

UC blogs

Saving the Mojave desert tortoise

Saving the declining populations of Mojave desert tortoise is a big challenge. But scientists think that raising newborn “hatchling” tortoises in a controlled environment in the Mojave National Preserve for a year, then releasing the juvenile tortoises into the wild, may help save this threatened species.

The protected tortoises — which live up to 80 years and can go without water for a year — have existed for eons, but are now being decimated by habitat loss and predation. Professor Brian Todd, in the Department of Wildlife, Fish and Conservation Biology at UC Davis, worries that the increasing use of Southern California deserts for solar and wind energy, will add to the loss of tortoise habitats, and add further pressure to regional wildlife habitats. While developing renewable energy to combat climate change is a good thing, in this case it impacts desert species and their habitats.

Professor Brian Todd, UC Davis, with a Mojave desert tortoise.
Stepping up to the plate to save the Mojave desert tortoises is a triad of academics, government agencies, and corporations, who recently created the Ivanpah Desert Tortoise Research Facility. The new facility, located in the Mojave National Preserve, was designed for scientists to conduct research on juvenile tortoise survival. It was constructed largely by Chevron and Molycorp, and is managed by the National Park Service. Scientists from the University of California, University of Georgia, and elsewhere, are conducting a 15-year study to see if hatchlings released into the wild and/or relocated elsewhere can survive and reverse the population decline.

We can all keep our fingers crossed that this research will preserve desert tortoise populations, and serve as a model for conserving biodiversity.

Additional information:

  • “Protecting the desert tortoise,” video of UC Davis researchers and desert tortoises.
  • “Habitat selection, space use, and factors affecting recruitment of desert tortoises in the Mojave National Preserve”; Brian Todd website, UC Davis
  • “Baby desert tortoises get a headstart in the Mojave,” by Andy Fell and Kat Kerlin, Egghead blog, UC Davis. With a video of tortoises and scientists.
    A hatchling Mojave desert tortoise.
  • “Tortoise territory,” by Robin DeRieux, CA&ES Outlook magazine (see pages 2 and 10), UC Davis, spring/summer 2012.
  • “Mojave National Preserve celebrates dedication of Ivanpah desert tortoise,” Mojave National Preserve website.

Desert tortoises are well camouflaged in the California desert.

Posted on Tuesday, September 16, 2014 at 9:44 AM

A disheartening new pest invades California vegetable gardens

Bagrada bugs feeding on a tomato. (Photo: Jennifer Evangelista, San Luis Obispo)
California gardeners harvesting their summer produce may encounter a new pest – the bagrada bug. The native of Africa made its first California appearance in Los Angeles County six years ago and has been moving eastward and northward ever since.

“Citizen scientists have been instrumental in reporting the occurrence of bagrada in various counties and are helping map its current distribution,” said Surendra Dara, UC Cooperative Extension advisor in San Luis Obispo, Santa Barbara and Ventura counties. “This is a very serious pest. It is wiping out gardens, and is of great concern for small-scale and organic growers.”

Bagrada bugs are major pests of cruciferous vegetables, such as cabbage, kale, cauliflower, Brussels sprouts and broccoli, but they don't appear to be picky eaters. They have been known to feed on a wide variety of garden vegetables in California, including green beans, cantaloupe, corn, peppers, potatoes, tomatoes and sunflower. Even landscape plants are not immune. Bagrada bugs have been found feeding on ornamental plants in the mustard family, like sweet alyssum, stock and candytuft.

Bagrada bugs congregating on sunflowers. (Photo: Larry Adcock, Arroyo Grande)
The adult bagrada bugs are about the size of watermelon seeds and have shield-shaped black backs with white and orange markings. Young bagrada bugs – with their red, black and white markings – are sometimes mistaken for ladybugs. But bagrada bugs have piercing and sucking mouthparts which cause dead spots on plant leaves and stems when they feed, and result in stunted growth, plant deformities and plant death.

Dara said scientists had hoped cold winter temperatures in northern counties of California would limit the bagrada's northward march, but that hasn't been the case so far.

“Bagrada bugs can survive the winter or cold nights by entering the top layer of the soil around crops,” he said. "They start appearing again in early spring and move from weeds to young vegetables."

For more information on bagrada bugs, see the Pest Note produced by the UC Integrated Pest Management Program. In addition, Dara regularly posts bagrada bug updates on his blog, Strawberries and Vegetables.

Distribution of bagrada bug in California, September 2014.
Distribution of bagrada bug in California, September 2014.

Posted on Friday, September 12, 2014 at 9:28 AM

About that lemoncello

One of the hazards of contributing to a shared blog, is that one forgets to post. So in this case, while I said in my last post that we would re-visit the lemoncello in mid-May, here it is September.  Time flies.

The lemoncello is a huge success, we've been enjoying it on the hot summer afternoons that are plentiful in Davis.  And here's how I got from pith to pleasure . . . .

The first steps in the lemoncello process were documented in this early Spring post.  The recipe calls for 6 weeks of steeping the lemon zest in the alcohol in a cool, dark place; preferably, in a place where it won't be disturbed.  I had placed mine in a place so cool, dark, and undisturbed it took me 45 minutes to find it.

But that resolved, I moved to the next step - filtering.

You can see that the zest from all of those lemons has settled to the bottom of the bottle.  Lemoncello aficionados recommend a 2-step filtering process.  The first step is to get most of the zest out using a fine sieve.

Look at all of this zest!

Quite a bit of solid material is left in the liquid after this process.

To remove these last solids, the liquid is filtered through a paper coffee filter. (Lemoncello purists, like coffee purists, would object to the use of a paper filter, saying it imparts a paper flavor.)

The next step is to add the cooled simple syrup.  The basic simple syrup recipe calls for equal parts of sugar and water, but for lemoncello less sugar is used.  For one 750ml bottle of base alcohol, you need 2-1/2 cups of water and 1-3/4 cups sugar.  Add the sugar to the water in a medium saucepan and heat over medium heat.  Bring to a gentle boil, stirring constantly, until the sugar is dissolved.  Let the mixture cool completely to room temperature before adding to the lemoncello base.

Decant the mixture, and put in a cool, dark place for another 45 days.  The addition of the simple syrup increases the volume, so you can't fit your mixture into the original bottle.

This mixture was moved into two tall glass bottles and set aside until early July.

You can put the finished lemoncello in the freezer or in the refrigerator.  Enjoy it alone or in a cocktail on a hot summer afternoon when you need a little something refreshing!

If you want to make your own lemoncello, an excellent resource is the blog LemoncelloQuest.

Posted on Tuesday, September 9, 2014 at 2:57 PM

Farmers invite visitors with new farm trail maps

The Sacramento River Delta Grown Agritourism Association map brochure invites, “Drive along winding rivers and sloughs in the heart of the California Delta; Visit quaint historic towns, shop at rustic farm stands or pick your own fresh fruit and vegetables; Taste Delta wines, picnic by the river, and enjoy the peaceful pace among generational family farms.”

The Capay Valley Farm Trail Map lists more than 40 farms in the Cache Creek watershed, and explains, “Capay Valley is a remarkable stretch of fertile land and rolling hills, home to a host of small and mid-size farms, natural wonders, and outstanding events…”

The North Yuba Grown Farm Trail Map brochure encourages visitors to “Enjoy the Flavors of North Yuba … Some olive trees in the area are more than 100 years old, and are still producing excellent olive oils. The vines cultivated for wine are forced to dig deep for water and nutrients, resulting in smaller yields but expressing intense flavors.”

As Californians' interest in local food and farming increases, farmers in many parts of the state are finding ways to invite their urban and suburban neighbors out to the farms to taste, tour, play and learn. Three groups of growers, Capay Valley Grown in Yolo County, North Yuba Grown in Yuba and Butte, and Sacramento River Delta Grown in Sacramento County, have just published new farm trail maps that promote agritourism in their unique farming regions. The maps are part of a UC Small Farm Program project, funded by a CDFA Specialty Crop Block grant, called, “Building a Farm Trail: Developing effective agritourism associations to enhance rural tourism and promote specialty crops.”

Each of the map brochures is a product of collaboration among the region's farmers and vintners, coordinated by the Small Farm Program and supported by a team of marketing, tourism and economic development professionals. The goals of the project include creation of maps, but also, more importantly, training and support for each group of growers in building sustainable and effective collaborative marketing associations that connect with the larger rural tourism community in their regions. Each group is now distributing their new maps, and is also working with a website designer to redesign their websites for clarity and customer appeal.

The Sacramento River Delta group put on their Wine and Produce Passport Weekend in early August to debut their maps. North Yuba Grown is sponsoring the North Yuba Harvest Festival, to be held on September 27 and 28, and Capay Valley Grown is planning an Open Farm Day on October 5 this year. The groups of growers will have a chance to share their experiences with each other at a regional workshop in November, and with other California agritourism operators at a statewide agritourism summit to be held in April 2015.

The California Statewide Agritourism Summit, organized by the UC Small Farm Program as part of the same project, will bring together agritourism associations and others involved in California agritourism from throughout the state to learn from each other. The summit will include planning sessions for the continuation of statewide farm trail and agritourism association networking and skill-sharing. For more information, please click here or contact UC Small Farm Program Agritourism Coordinator Penny Leff, (530) 752-7779.

 

Visitors tour a farm in the Sacramento Delta region during pear harvest season.
Posted on Monday, September 8, 2014 at 2:17 PM

The Clear Lake hitch get new protection

Clear Lake hitch spawning in Adobe Creek. (Photo: Richard Macedo, California Department of Fish and Wildlife)
The Clear Lake hitch, a large minnow found only in Clear Lake and its tributaries, was designated a “threatened species” last month under California's Endangered Species Act.

Introduced predatory and competitive fish species and low water flows in the hitch's spawning grounds have combined with other factors to throw hitch populations into decline, prompting its designation as a threatened species. With the new status, agencies can now solicit funds for stream and habitat improvements and any changes to the shoreline, tributaries and lake may only be made after carefully studying the potential impact on Clear Lake hitch.

“Anytime an animal gets listed, I believe it's an admission of failure on the part of society,” said Greg Giusti, UC Cooperative Extension natural resources advisor in Lake County. “We've been asleep at the switch.”

Giusti is mobilizing efforts to help the local residents, anglers and farmers deal with outcomes of the new designation.

Scientists determined the Clear Lake hitch was a distinct species in 1973. There are hitch in other Northern California lakes and waterways, but differences suggest the Clear Lake hitch took its form after geologic forces separated the lake from the Sacramento River watershed thousands of years ago.

The Clear Lake hitch spawn in creeks and streams in late winter and early spring. Eggs hatch in about seven days and a week later the free swimming young begin moving down stream. For 80 days the fish stay in marshy areas at the mouths of streams, feeding heavily on rice fly larvae. At about 2 inches in length, they move away from the shore into deeper water and, when mature, return to spawn in streams.

Pomo Indians traditionally harvested Clear Lake hitch in large numbers when free-flowing creeks and streams were teaming with spawning adults. The fish were dried and served as an important food source all year. Descendants of Native Americans wish to continue the practice.

According to Peter Moyle, professor in the Department of Wildlife, Fish and Conservation Biology at UC Davis, the fish were among the last native species in Clear Lake to be doing reasonably well until the early 1970s when three alien fishes became abundant in the lake - Florida largemouth bass, Mississippi silverside, and threadfin shad.

“The bass is a terrific game fish,” Moyle said. “The Florida bass was introduced to improve the fishery. However, they became very abundant and are voracious predators of hitch. Likewise, the silverside and shad likely prey on hitch larvae and compete with hitch for their zooplankton food.”

Clear Lake hitch have also been impacted by water extraction from the tributaries upstream, mainly for irrigation, plus the construction of bridges, dams and other structures in their spawning streams.

While in the past there were tens of thousands of Clear Lake hitch spawning in dozens of tributaries, in recent years, population has been reduced to a few thousand and they reportedly spawn in only two streams. Because of the low water flows in current drought conditions, Giusti said, there was virtually no Clear Lake hitch spawn at all in 2014.

Posted on Thursday, September 4, 2014 at 8:57 AM

Next 5 stories | Last story

Webmaster Email: jewarnert@ucanr.edu