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Wings for Integrated Pest Management
Falcons and owls and bats….oh my! Unless you are a starling, a rodent, or an insect, these winged critters may not seem as scary as lions and tigers and bears. To starlings, rodents and insects, however, this scary trio of winged critters represents a potentially deadly “tool” of Integrated Pest Management (IPM). The Napa Sustainable Winegrowing Group (NSWG) and the Napa RCD, in their efforts to support sustainable watershed management, have hosted several workshops with a focus on these winged critters and the benefits they can provide to agricultural communities.
On August 13, 2001, the Napa Sustainable Winegrowing Group (NSWG) hosted falconer Tom Stephans to demonstrate how falcons can be used as a tool for integrated pest management (IPM). According to Stephans, “falconry is a low-tech, non-toxic and highly effective means of pest control. In viticulture, falcons can be used to reduce crop damage caused by non-native starlings.
Falcons instill a deep-seated terror in starlings and other birds. When a falcon is released, one can hear small birds in the surrounding trees sending out warning calls. The falcon does not need to kill the birds to get the desired result. The birds need only see the dive-bombing, swooping falcons, and they begin to scatter,” says Tom.
Tom owns one of only five falconry businesses in the country. He resides in Ramona, California and has been employed by the US Air Force and a variety of vineyards. His services are frequently used to clear Air Force runways of birds and to protect starling-infested vineyards. He can be contacted at (760)789-1493, (760)801- 2207 or falconair4s@home.com.
Owls are another winged critter that can be used as an IPM “tool. NSWG and the Napa RCD have promoted the distribution of barn owl boxes in vineyards for the past few years. The idea of utilizing owls to manage pests is becoming widely accepted in the Napa Valley and owl boxes can be seen in many vineyards.
Barn owls are one of the most skillful rodent hunters in North America. Their dish shaped face, in conjunction with their asymmetrical ears, gives them the ability to triangulate on their prey like radar. On average, a barn owl will eat 155 gophers per year.
Installing a barn owl box provides a place for the barn owls to roost in the fall and a safe place to nest and raise a family of owlets in the spring. Napa’s “Habitat for Hooters” (HFH) will build, install and clean owl boxes for a small fee that includes membership. Local high school students build HFH owl boxes and the money raised from owl box sales goes towards scholarships.
The HFH program director, Janet Barth, can be reached at (707)224-3464.
Over the past two years, the Napa RCD has hosted three presentations about bats and the role that they can play in IPM. Bats are also the latest IPM “tool” that NSWG is promoting for use in vineyards. UC research has confirmed that Mexican free-tailed bats and Yuma myotis bats, both common in Napa County, prey upon night-flying insects which include serious farm and urban pests such as moths, beetles, flies, midges, mosquitoes and plant bugs.
Bats help keep the insect population in balance. A typical colony of 150-200 bats will eat 5 pounds of insects per night or several million insects each season. The key to the bats’ insect gathering ability is echolocation, which serves as a form of personal sonar. Their vocal squeaks, mostly above human hearing range, bounce off an insect and are picked up by their super sensitive large ears. The skin between the bat’s legs is then used as a basket to scoop up the insect and the bat does a belly tuck to lower its head down to eat.
Bats are the second largest mammal group in the world, comprised of roughly 950 species. All of the species found in Northern California are insect eaters that eat both flying and ground insects. However, in spite of their benefit to farms and the environment as a whole, little effort has been made to protect the roosting and foraging habitat needed by bats. More than half of American bat species are in severe decline or are already listed as endangered, according to Merlin Tuttle, president of Bat Conservation International (BCI). In California, at least 10 of 24 species are designated “of special concern” by the State Department of Fish and Game, meaning their numbers are in decline and they require special management to prevent further losses.
Installation of bat houses and enhancement of roost habitat are two ways to attract bats. Please note that, like owls and falcons, bats may not be legally captured. For a handbook detailing bat house construction or for general information about bats, contact Bat Conservation International at (512)327-9721 or by mail at PO Box 162603, Austin, TX 78716.
The RCD Continues to Study Sediment in the Watershed
The first year’s field work under the Farming in a Watershed Context grant has been completed and presented to the project’s Technical Advisory Team. Under this program, paired watersheds with contrasting vineyard management practices were selected for measurement of several environmental parameters, including flow and suspended sediment concentration. Data from the study will help to determine the effectiveness of various erosion control practices.
Despite some problems with equipment and lab work, we had a good year and believe that our concept is sound. For the coming wet season, we have made several equipment-related changes that should give us better flow information and will maximize the number of suspended sediment samples.
Many thanks to the people at Spring Mountain Vineyards and Domaine Chandon. Thanks also to those who have helped with our Technical Advisory Team for volunteering their time to make this work possible and to the Regional Board for funding the necessary lab work.
The work of Farming in a Watershed Context will be continued and expanded upon under an upcoming project, Sediment and Stewardship , funded by the State Water Resources Control Board. RCD staff have been busy working on the final Scope of Work for our contract and expect to receive funding in January 2002. The $200,000 awarded to the Napa RCD by the State Board provides us with an opportunity to expand our monitoring of sediment in the Napa River watershed. We will establish sediment stations on the Napa River, and/or on key tributaries of the river, and monitor both turbidity and suspended sediment.
Our intention is to use turbidity as a predictor of suspended sediment load, using techniques pioneered by the Redwood Sciences Laboratory in Arcata. There will be plenty of opportunity for volunteer monitors to help in this endeavor, which will produce information that is desperately needed and not otherwise available.
Northern Watershed Habitat Assessment
Funded by the California Department of Fish and Game (DFG), the RCD recently completed fish habitat assessments on the northern portion of the Napa River and eight of its tributaries. Four interns were hired to work in the field this summer to walk the creeks and inventory fish habitat. All of the interns were college students studying biology or restoration ecology. We enjoyed having them around this summer and hope that they and others will join the RCD in future projects.
Following DFG fish habitat protocols, the interns braved the blackberries and yellow jackets and collected information such as: stream classification, availability of instream shelter, substrate composition, percent canopy, bank composition and vegetation, temperature, pool depth, presence of large woody debris and cobble imbeddedness.
The data is currently being entered into the DFG database and will be analyzed to assess habitat for steelhead trout. The RCD hopes that the data and information garnered from this project will lead to future restoration opportunities in the area. Future projects could include the planting of native riparian plants, installation of instream habitat structures, and/or removal of fish passage barriers.
Overall, the habitat assessment project was a success. Many young of the year fish, perhaps steelhead or resident rainbow trout, were found in the pools along with a few larger fish. The dry year left stream flows at lower than normal levels but the project gave us a good picture of the present state of fish habitat in the northern watershed.
Local Education Consortium Reaching Out to Teachers
The Napa RCD has entered into a partnership with several public, private, and non-profit agencies in Napa County that provide environmental education services to the teachers and children of Napa County. The newly formed consortium is currently developing an environmental education manual that will be distributed to every school in Napa County. The manual is intended to acquaint teachers with a variety of environmental education services and activities available in the county. Information such as the curriculum standards met by each service, the intended grade level for each activity, and a general description of each program will be included .
The consortium hopes to make it much easier for teachers to get their students involved in the many wonderful environmental education opportunities available in Napa. Presently, the group is trying to secure funding for the manual and hopes to increase its membership to include additional environmental education agencies. For more information about the work of the consortium or to donate funds for the manual, please contact Michael Champion at 252-4188 or michael@naparcd.org.
NSWG Draws a Crowd of Spanish-Speaking Vineyard Workers
On July 13, 2001 the Napa Sustainable Winegrowing Group (NSWG) held its 2nd annual Spanish-speaking workshop. By offering the Spanish-speaking workshop, NSWG reaches out beyond vineyard owners and managers and is targeting the farm workers who implement conservation work in the field.
The seminar focused on erosion control issues and drew over fifty participants from local vineyards. Vineyard workers discussed and shared ideas about sustainable farming, creek protection, water quality issues, winter erosion control preparation and the proper installation of erosion control measures, such as silt fences and straw bale dikes.
For the past four years, NSWG has received funding from the USDA-NRCS under the EQIP (Environmental Quality Incentives Program) to educate the Napa community on sustainable farming practices. This year’s English speaking workshops included: Ecology for the New Millennium and Water Use and its Place in Sustainable Farming. Ecology for the New Millennium invited members of the non-farming community to learn about sustainable vineyard practices that are being implemented in Napa County. Water Use and its Place in Sustainable Farming focused on the use of water in the vineyard including the use of dry-farming and recycled water.
Many Thanks to the Redwood Creek Clean-up Crew
On Saturday July 21, six dedicated volunteers spent their morning pulling debris out of a stream reach on Redwood Creek.Michael Champion noted that, “Most of the creek appeared to be in good shape but areas along the road with turn-outs needed the most work.” The Napa RCD, with assistance from the Hess Collection Winery, organized the creek clean-up event at the request of a local landowner.
In order for the project to take place and be successful, landowner access agreements were obtained and announcements were published in the Napa Register. Volunteers met at the Hess Collection Winery on Redwood Rd. at 9 am and worked until 1 pm.
As is the case with most creek clean-ups, volunteers found some unusual items in the creek. Among the more notable things found were a jet ski, a dishwasher, tables and chairs, and parts of a pick up truck.
The Napa RCD would like to thank the dedicated volunteers, the staff at Hess Winery for their cooperation and donation of pick-up trucks, and the County Public Works Department for removing the collected debris.
If you are interested in helping in a local creek clean-up, you will have an opportunity on September 15th. See related volunteer opportunities on page 3.
Volunteer Opportunities
Annual Napa Creek Clean-Up
September 15, 2001—8:30 am to 12:00 pm
Napa Creek Manor—1300 Jefferson
In conjunction with the California Coastal Commission’s Annual Coastal Clean-up, the Napa RCD and the City of Napa are sponsoring a clean-up of Napa Creek from California Boulevard to the Napa River. Debris will be removed from the creek before the rainy season in an effort to decrease the potential threat of flooding and to enhance the beauty and health of Napa Creek. Volunteers will meet at 8:30 a.m. in the lobby of the Napa Creek Manor located at 1300 Jefferson St. Contact Michael Champion at 252-4188 or michael@naparcd.org for more information.
Get a free Rain Gauge
Sign up Now to Become a Rainfall Monitor
We need more volunteers to collect daily rainfall data. It’s quick, it’s easy and we will provide you with your very own rain gauge, data forms and three minute training. Rainfall within the Napa River watershed varies dramatically depending on the topography and meso-climates of any given area. The amount of rainfall in an area, per storm and per rainy season, can significantly affect the amount of runoff into streams, erosion, vegetative cover, groundwater recharge, stream water chemistry, and runoff of nonpoint source pollution. A few minutes of your time in the morning to jot down how much rain fell the previous night will provide valuable information. If you are interested, please contact Kathleen Edson at 252-4188 or kathleen@naparcd.org.
Streamgagers with a Sense of Adventure Needed
Ever wonder how much water is in your local stream or creek, how fast it's going or if it is approaching flood stage? So do we, which is why the RCD maintains a network of streamgaging sites throughout Napa Valley. During
the winter, RCD staff members and volunteers venture out in the field to take a number of stream velocity measurements at each streamgaging site. With this data, we can establish what the discharge, or flow rate, is at different water levels. But we can’t do it alone. The RCD depends on
volunteer support to assist with streamgaging efforts. So, if you are interested in local natural resources, have an adventurous spirit, and don’t mind getting a little wet - then you’re the volunteer we are looking for. Please contact Blaine at 252-4188 or blaine@naparcd.org.
Educational Insert: Sudden Oak Death in Napa County
Sudden Oak Death: Background:
Sudden Oak Death (SOD) is a disease that is killing large numbers of tan oaks, coast live oaks and black oaks in eight of California’s coastal counties, including Napa County. Most recently, it has been found in the southwest corner of Oregon, near Brookings. The disease is caused by a previously unknown species of Phytophthora (Phy-TOFF-thoruh), a member of a group of fungi also known as water molds or brown algae. The new fungus-like organism has recently been classified as phytophthora ramorum, derived from the Latin “ramus” meaning branch and indicating that the disease affects twigs and branches. This educational insert addresses some of the questions commonly asked by homeowners and is based on the current understanding of Sudden Oak Death and information garnered from other disease complexes that involve the phytophthora species.
First seen on tan oak in Mill Valley in 1995, SOD has now been confirmed in eight central coast counties: Napa, Marin, Sonoma, Mendocino, Santa Cruz, Monterey, San Mateo and Santa Clara. The name Sudden Oak Death is used because of the rapid color-change of leaves from green to brown. However, the disease is not as ‘sudden’ as it may appear; a tree may be infected with P. ramorum for a year or more before exhibiting the sudden change in foliage color. P. ramorum also infects, but does not usually kill, a number of other woody plant species found in California including rhododendron, huckleberry, California bay laurel, madrone, and buckeye. The pathogen has been found to exist on manzanita in a laboratory setting. These ‘host’ plants allow P. ramorum to reproduce rapidly on their leaf surfaces and may allow for the build-up of spores and serve as a source of infection. The pathogen may be spreading from the leaves of the host plants to the trunks of the oaks through the soil, water, and air.
SOD has the potential to cause significant decline in a number of California’s native plants and mortality in a number of California oaks. The most recent confirmed findings in California have been in Mendocino County just outside of Boonville and in Skyline Wilderness Park in eastern Napa County. Other areas in Napa County where SOD has been confirmed are in the western hills of the Napa Valley along Mt. Veeder and Partrick Road. A recent reported finding at Westwood Hills Park is in the process of being confirmed.
Recognizing Sudden Oak Death:
The symptoms of P.ramorum on Coast live oak, California black oak and Shreve oak are similar. Typically, the first sign of infection is a bleeding ooze on the trunk of the tree from ground level to 6 feet or higher. The ooze may be dry and hard or may disappear completely leaving a blackened bark. During rainfall events, the ooze is often washed away and is very difficult to find. Discolored moss may be found in areas around oozing. Chipping away at the edge of the blackened or oozing area will reveal dead patches of the outer bark surrounded by black zone lines. In the early stages of the disease, the crown of the tree may appear healthy.
Not all bleeding on oak stems and limbs is indicative of SOD. Other causal agents may be responsible. Consult with a certified arborist or your UC Cooperative Extension office for confirmation of P. ramorum. Confirmation of P. ramorum is under the jurisdiction of the County Agricultural Commissioner and can currently only be done by two laboratories.
As time progresses, the crown may begin to thin or undergo a complete color change from green to brown in a couple of weeks. The leaves are not usually spotted and do not show other symptoms of the disease until they turn uniformly brown. In later stages of decline, sawdust from bark beetle attack is visible in the bark crevices of the trunk. Hypoxylon fungus, which fruits abundantly on dead portions of the tree, may also be visible during the later stages. This fungus will appear as a carbon-black nodule on the side of the tree.
It is easiest to recognize P. ramorum on living trees. If you find a dead oak, carefully examine the neighboring trees to see if bleeding can be found. In addition, check to see if multiple tree and shrub species in an area all show symptoms of disease (i.e. bleeding oaks next to bay trees with leafspot at the tip.) Identifying P. ramorum on host plants is not easy. Symptoms of other tree diseases may be confused with the symptoms of P. ramorum.
What to do for oaks that do not have the symptoms of Sudden Oak Death
The best defense against a range of plant pathogens and insect pests is to promote tree health. The following are some general guidelines recommended by UC Cooperative Extension Agents.
Avoid frequent irrigation of established oak trees. Oaks are adapted to the dry Mediterranean climate that prevails in central coastal California. Most established oaks do not require supplemental irrigation except under severe drought conditions. A certified arborist, master gardener, or other specialist should be contacted for irrigation advice should extreme drought conditions occur.
The root zone of oak trees, the area under the crown plus 1/3, is the most vulnerable part of oaks and should be treated as a ‘zone of no disturbance.’ Avoid activities such as paving and soil compaction around the root zone. Rather, apply 4 – 6 inches of mulch under the tree canopy leaving a ‘no mulch’ area of at least two feet around the area where the trunk fans out to the roots.
Protect the stem and lower branches from injury and fertilize the tree if it begins to show symptoms of deficiency, such as yellowing of the leaves. Consult a certified arborist to confirm deficiency prior to applying fertilization.
What to do with oaks that have symptoms of Sudden Oak Death
Monitor oaks in urban settings and remnant forests for bleeding symptoms year round. If the bleeding symptom is detected and you suspect the tree is infected with P. ramorum, consult with a certified arborist, pest control advisor, horticulturist or the local Agricultural Commissioner. Professionals can provide you with assistance, but only a lab analysis can truly confirm the presence of the pathogen. Eradication of the pathogen is currently biologically and physically impossible. A number of compounds are being tested experimentally, but current data are insufficient to warrant the recommendation of any pesticide treatment.
Preventing the spread of Sudden Oak Death
Because P. ramorumhas been confirmed in Napa County, the California Department of Food and Agriculture regulates the movement of host plants and woody material out of the county. Do not transport freshly cut firewood or soil off your property.
When oaks and host plants are cut or pruned, chip the branches and split the wood, and leave it on your property. Current regulation requires that these tree parts stay on the property – all host materials, including bay and madrone pruning for example, must stay on the originating property. Where possible, place the trimmings in a sunny location to promote drying.
More Information
The following websites contain up-to-date information about Sudden Oak Death and links to other relevant sites: www.suddenoakdeath.org, cemarin.ucdavis.edu, and camfer.cnr.berkeley.edu/oaks. University of California Cooperative Extension county offices can provide additional information. The local extension office can be reached at 253-4221.
References:
Gasser, Don. August 2001. Personal conversations.
Pramuk, Bill. August 2001. Sudden Oak Death Update: Skyline Park. Out on A Limb. Britton Tree Services, Inc. Volume 11, No. 3.
Svihra, Keirnan, Palkovsky, and Storer. June 2001. Sudden Oak Death: An Update of the Facts. UC Cooperative Extension and UC Berkeley. Pest Alert No. 4a.
Marin County UC Cooperative Extension. Sudden Oak Death. http://www.ucdavis.edu. Information obtained from web in August 2001.
Report to the California Oak Mortality Task Force. July 2001. www.cnr.berkeley.edu/…monthlyreports.html. Information obtained from the web in August 2001.
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