Invasive and Noxious Weeds of Rangeland in Santa Barbara County

Transcription

1 Invasive and Noxious Weeds of Rangeland in Santa Barbara County A presentation to the Livestock and Land Program October 22, 2011 Cathy Fisher County of Santa Barbara Agricultural Commissioner s Office 1

2 Noxious and Invasive Weeds not just a pretty picture Invasive weeds can increase maintenance costs for agriculture, homes and roads Contaminated crops, mowing, manual control, and spraying A 1999 estimate put the economic cost of invasive plant in natural areas, agriculture, and gardens at $35 billion per year. Direct competition for resources Prevent seedling regeneration Reduce food sources and habitat for wildlife Disrupt native plant-pollinator interactions Change structure, function, and composition of plant community Alter hydrologic flows and conditions Change soil structure and chemistry Influence frequency and intensity of fires, floods, and other disturbance regimes Change patterns of nutrient cycling

3 Noxious and Invasive Weeds not just a pretty picture Invasive weeds can reduce plant and wildlife diversity Monocultures crowd out natives In the U.S. an estimated 46% of rare, threatened, and endangered species are at risk from invasive plants, animals, and pathogens

4 Noxious and Invasive Weeds not just a pretty picture Invasive weeds can reduce rangeland and habitat value Toxicity or spines - livestock and wildlife don t graze A 1999 estimate put the economic cost of invasive plant in natural areas, agriculture, and gardens at $35 billion per year.

5 Noxious and Invasive Weeds not just a pretty picture Invasive weeds can increase flood risk Clogging creeks River Road Bridge near Norco in Riverside County, was damaged twice in 3 years and was finally knocked off its foundation, causing nearly $1 million in damage. The bridge was eventually replaced at a cost of $8 million.

6 Noxious and Invasive Weeds not just a pretty picture Invasive weeds can increase fire risk Carry fire across the landscape, change the fire season

7 Weed management, natural disasters and gardeners can spread weeds Mowing wrong time Creating bare ground Faster growing weeds can be enhanced by fire Weeds can be spread by floods Contaminated equipment and personnel Planting inappropriate species Weed management, natural disaster and gardeners can spread weeds. Mowing wrong time, when flowers are mature. Seeds or propagative plant parts can be spread. Fires, fuel breaks, and weed control can create bare ground, which can be susceptible to weed invasion Where native vegetation is not fire adapted, faster growing weeds may replace native vegetation after a fire or where the vegetation is slower growing. Contaminated fire fighting equipment and personnel. Dozers, fire vehicle, helicopters, and boots can spread weeds Reseeding or replanting with inappropriate species.

8 California Agricultural Law 403. The department shall prevent the introduction and spread Basically, of injurious noxious insect or weeds animal pests, are plant diseases, and noxious weeds. specifically named weeds detrimental to agriculture 461. The department may conduct surveys or investigations of any nursery, and orchard, habitat vineyard, agricultural commodity, agricultural appliance, farm, or other premises within the state liable to be infested or infected with any pest as defined in Section 5006 or disease, including any infectious, transmissible, and contagious diseases of Agricultural Commissioner has livestock and poultry, for the purpose of detecting the presence of, or authority determining to the status of, the pest or disease. The director and the county prohibit agricultural in trade, commissioner shall consult concerning these surveys or investigations and in the conduct or implementation of any control or eradication to abate, activity when the provisions of this code provide joint responsibilities in connection with the pest or disease. prohibit movement "Noxious weed" means any species of plant that is, or is liable l to be, troublesome, aggressive, intrusive, detrimental, or destructive to agriculture, silviculture, or important native species, and difficult icult to control or eradicate, which the director, by regulation, designates to be i d I d t i i h th t i h ll b The Food and Agricultural Code defines a "noxious weed" as: any species of plant that is troublesome, aggressive, intrusive, detrimental, or destructive to agriculture, or important native species, and difficult to control or eradicate, The California Department of Food and Agriculture designates which plants shall be considered noxious weeds, but cannot name plants as noxious if that designation would be detrimental to agriculture. 8

9 Invasive vs. Noxious Not regulated Unless also noxious Non-native native Might be sold in trade Regulated Might be invasive Most are non- native Prohibited in trade Weed management practitioners have specific definitions for the terms invasive and noxious. (Frequently, though the terms are used interchangeably.) Invasive weeds are not regulated, unless also noxious, are non-native and might be sold in trade Noxious weeds are regulated, are usually but not always invasive, most are nonnative, and are prohibited in trade

10 Weed Increase Over Time and Control Potential Acres Infested Eradication simple Introduction Eradication feasible Eradication unlikely, intense effort required Detection Local control and management only Public awareness typically begins Control Costs Plant absent Scattered locations Numerous locations At or near biological potential Time This graph illustrates the importance of controlling an introduced weed early - a concept known as Early Detection and Rapid Response. As time goes by, after a plant is introduced it begins to naturalise. If the plant is found at this time eradication costs would be low, but detection is difficult. An introduced plant may be found in scattered locations and eradication is still feasible. This is the ideal time at which to attempt an eradication. Otherwise costs begin to exponentially increase and eradications are less likely and become local eradication or management projects. 10

11 Problem noxious weeds of Santa Barbara County Artichoke thistle, Cynara cardunculus Purple starthistle, Centaurea calcitrapa Onionweed, Asphodelus fistulosus Pampasgrass, Cortaderia selloana & Cortaderia jubata Yellow starthistle, Centaurea solstitialis Fountaingrass, Pennisetum setaceum These are the most problematic invasive and noxious weeds on the Gaviota Coast: Carnation spurge Artichoke thistle Purple starthistle Giant reed Onionweed Pampasgrass Yellow starthistle Fountaingrass Some of these weeds are widespread, some are rare, some are limited to riparian areas. Most are limited to some ecological niche. Because of this there is a need to strategize management and prioritize eradication.

12 Rare noxious weeds Early Detection Targets Punagrass, Achnatherum brachychaetum Skeletonweed, Chondrilla juncea Yellowspine thistle, Cirsium ochrocentrum Russian knapweed, Acroptilon repens Silverleaf nightshade, Solanum elaeagnifolium Carnation spurge, Euphorbia terracina These are the most problematic invasive and noxious weeds in Santa Barbara County: Punagrass, Achnatherum brachychaetum Skeletonweed, Chondrilla juncea Yellowspine thistle, Cirsium ochrocentrum Perennial sowthistle, Sonchus arvensis Russian knapweed, Acroptilon repens Silverleaf nightshade, Solanum elaeagnifolium Scotch broom, Cytisus scoparius French broom, Genista monspessulana Some of these weeds are widespread, some are rare, some are limited to riparian areas. Most are limited to some ecological niche. Because of this there is a need to strategize management and prioritize eradication.

13 Punagrass Achnatherum brachychaetum Here are some of my primary targets. My priorities are the uncommon weeds or niche limited weeds where I feel I have a chance at making a long-lasting impact. We have 4 A rated weeds in Santa Barbara County Punagrass an A rated weed that is known from 4 counties in California. First found 1987 in Happy Canyon in the Santa Ynez Valley. Eradication attempted. Never fully eradicated I am currently assisting the ranch owner with herbicide treatment.

14 Punagrass Location

15 Punagrass Achnatherum brachychaetum Found near Happy Canyon Rd, Santa Ynez Horses, cattle won t eat it Tough to mow Densely tufted perennial with stiff pointed leaves Reproduces by seed from cleistogamous and aerial flowers The grass blade is a sharply pointed rolled leaf. When you place your hand on the plant the sharpness is apparent, and you can understand why horses and cattle won t eat it. Besides being spiky it is very tough to chew, mow or pull out. But the root crown is shallow and generally easy to pop out with a shovel. Several native needlegrass (Achnatherum, Nassella) species resemble punagrass. However, native needlegrasses do not produce cleistogamous seed within the leaf sheaths at the bases of plants. And are not as weedy.

16 Skeletonweed Chondrilla juncea Plants exist as basal rosettes until flowering stems develop at maturity and rosette leaves whither. Rosettes produce 1 or more flowering stems with numerous branches. Stem leaves often absent or bract-like, but when present resemble reduced rosette leaves. Upper stems mostly lack hairs, but typically have dense, bristly, downward pointing hairs at the base. Pointed hairs are characteristic. Asteraceae: Limited distribution, 16 counties, just north of SY Mts Live Oak Camp Herbaceous perennial or biennial, with rigid, wiry flowering stems to 1 m tall, milky sap. Plants exist as basal rosettes until flowering stems develop at maturity and rosette leaves whither. Persistent flower stems can hinder harvest machinery. Plants are highly competitive for water and nutrients. Reproduces only by clones produced vegetatively from adventitious buds on roots and asexually by apomictic seed Seeds primarily disperse with wind, but also by water, animals, and human activity Disturbed soils of roadsides, croplands, especially irrigated grain fields, semi-arid pastures, rangelands, and residential properties. Grows best on well-drained, sandy or gravelly soils in climates with cool winters and hot, relatively dry summers without prolonged drought. Tolerates a wide variety of environmental conditions, including rainfall less than 250 mm (10 in) to more than 1200 mm (~50 in), cold winter areas, and continental climates. Severe infestations are less common on heavy clay soils. Moderate soil disturbance, such as grain cultivation alternated with grazing on a yearly basis, encourages infestations by dispersing rootstocks. Under moist conditions, shallow burial of seed by hooves of grazing livestock appears to promote seed germination. Increasing nutrient levels of poor soils discourages infestation by increasing competition from other vegetation dandelion has unbranched, leafless, hollow, non-persistent, fleshy flowering stems and seeds without small scales at the apex. In addition, dandelion is typically found in turf and gardens. Chicory (Cichorium intybus L.) is similar to rush skeletonweed and dandelion, but has rosette leaf lobes pointing outwards or forwards and not always opposite, and basal leaves with a few rough coarse hairs. Persistent rigid stems with clusters of flower head bracts (and sometimes seeds) on old stems distinguish rush skeletonweed from dandelion The biocontrol agents skeletonweed gall midge (Cystiphora schmidti), skeletonweed gall mite (Eriophyes chondrillae), and rush skeletonweed rust (Puccinia chondrillina) have been released in California and can control some infestations. All are established in California. Where infestations are present, cattle and sheep will readily graze the rosettes and shoots until the stems become lignified. Grazing will reduce seed production, and few viable seed will pass through a ruminant digestive system.

17 Skeletonweed Location

18 Skeletonweed Chondrilla juncea Found east of Lake Cachuma and in Carpinteria Highly competitive, interferes with harvesting equipment Herbaceous perennial or biennial Reproduces by clones produced vegetatively from adventitious buds on roots and asexually by apomictic seed Known to occur in 16 counties in California. In Santa Barbara County, occurs west of LC and on side of Casitas Pass Rd in Carpinteria. Persistent flower stems can hinder harvest machinery. Plants are highly competitive for water and nutrients. Reproduces only by clones produced vegetatively from adventitious buds on roots and asexually by apomictic seed Seeds primarily disperse with wind, but also by water, animals, and human activity Asteraceae: Limited distribution, 16 counties, just north of SY Mts Live Oak Camp Herbaceous perennial or biennial, with rigid, wiry flowering stems to 1 m tall, milky sap. Plants exist as basal rosettes until flowering stems develop at maturity and rosette leaves wither. Persistent flower stems can hinder harvest machinery. Plants are highly competitive for water and nutrients. Reproduces only by clones produced vegetatively from adventitious buds on roots and asexually by apomictic seed Seeds primarily disperse with wind, but also by water, animals, and human activity Disturbed soils of roadsides, croplands, especially irrigated grain fields, semi-arid pastures, rangelands, and residential properties. Grows best on well-drained, sandy or gravelly soils in climates with cool winters and hot, relatively dry summers without prolonged drought. Tolerates a wide variety of environmental conditions, including rainfall less than 250 mm (10 in) to more than 1200 mm (~50 in), cold winter areas, and continental climates. Severe infestations are less common on heavy clay soils. Moderate soil disturbance, such as grain cultivation alternated with grazing on a yearly basis, encourages infestations by dispersing rootstocks. Under moist conditions, shallow burial of seed by hooves of grazing livestock appears to promote seed germination. Increasing nutrient levels of poor soils discourages infestation by increasing competition from other vegetation dandelion has unbranched, leafless, hollow, non-persistent, fleshy flowering stems and seeds without small scales at the apex. In addition, dandelion is typically found in turf and gardens. Chicory (Cichorium intybus L.) is similar to rush skeletonweed and dandelion, but has rosette leaf lobes pointing outwards or forwards and not always opposite, and basal leaves with a few rough coarse hairs. Persistent rigid stems with clusters of flower head bracts (and sometimes seeds) on old stems distinguish rush skeletonweed from dandelion The biocontrol agents skeletonweed gall midge (Cystiphora schmidti), skeletonweed gall mite (Eriophyes chondrillae), and rush skeletonweed rust (Puccinia chondrillina) have been released in California and can control some infestations. All are established in California. Where infestations are present, cattle and sheep will readily graze the rosettes and shoots until the stems become lignified. Grazing will reduce seed production, and few viable seed will pass through a ruminant digestive system.

19 Yellowspine Thistle Cirsium ochrocentrum On Santa Rosa Island, near the pier Serious spines. Cattle, horses won t eat it Clump- or patch-forming perennial Reproduces by seed and vegetatively from creeping roots A - rated This is an uncommon plant in California known from only 5 counties. In Santa Barbara County, it is only known from Santa Rosa Island. This is a vicious weed very stiff, sharp spines. Cattle, horses won t eat it. Asteraceae: Erect prickly plants with purple, pink, or white flower heads that consist only of disk flowers. Clump- or patch-forming perennials Open disturbed sites, roadsides, fields, pastures, hillsides, rangeland, forest openings. Thistles typically do not tolerate deep shade or constantly wet soils. Often inhabit shallow sandy soils Reproduces by seed and vegetatively from creeping roots Most seeds fall near the parent plants or disperse short distances with wind. Some seeds disperse to greater distances with human activities, water, soil movement, and as seed or hay contaminants. Birds and small mammals can consume and disperse some seeds. Seed dormancy at maturity is variable, depending on environmental conditions and biotype. Heavy grazing and disturbances that create bare soil patches facilitate seedling establishment and survival. several native species are difficult to distinguish from yellowspine and wavyleaf thistles, and plants should be positively identified before an eradication plan is implemented. Only yellowspine and wavyleaf thi tl h ll fth f ll i h t i ti i l ith i

20 Yellowspine Thistle Location

21 Weed Alert! Geraldton carnation spurge Euphorbia terracina Highly invasive Monotypic stands Wide growth range Currently uncommon but potential for spread is high (EDRR target) Toxic sap Temporary blindness Dermatitis Noxious weed B rated HIGHLY INVASIVE Euphorbia terracina forms dense thickets which outcompete native species for space, light and nutrients. Its rapid growth and prolific seeding gives it the potential to invade areas of healthy native habitat. It forms monotypic stands within openings in coastal sage scrub. It has explosive seed dispersal. Resprouts readily when cut, grazed, or burned. Seed production sustained over 3 or more months within a population annually. It can survive in a wide variety of conditions cool, hot, dry, moist, sunny, or shady. Carnation spurge can form dense patches in a wide variety of habitats such as disturbed grasslands, coastal bluffs, dunes, salt marshes, riparian areas and oak woodlands. CURRENT California DISTRIBUTION IS LIMITED Euphorbia terracina is currently relatively rare but spreading in California. A herbarium record of the UCLA Botanic Garden exists from It is established in coastal regions from Malibu to Palos Verdes, inland up Yerba Buena and Mulholland Road, up Topanga Canyon and Old Topanga Canyon roads, over the mountains into Rancho Sierra Vista, and westward to highway 150 in Ventura County. In Santa Barbara County, it has been found at the intersection of Highway 150 and 192 and in the El Capitan region. Also found in Los Angeles County. Fire provides optimal conditions for germination and the establishment of new populations. E. terracina is an aggressive weed, but it does not persist on frequently cultivated soil. It is a serious competitor with pasture plants and is toxic to stock. Stock losses due to hydrocyanic acid have been attributed to the plant in New South Wales, but stock poisoning is rare because the sap makes the plant unpalatable to animals (Parsons and Cuthbertson, 1992). In Western Australia, E. terracina is a serious weed of grazing land (Hussey et al, 1997).

22 Carnation Spurge Locations

23 Geraldton carnation spurge Carnation spurge is a relatively new pest in California, having been discovered in California in the 1980s, and in Santa Barbara County in So far, in Santa Barbara County it has only been found in Carpinteria and at El Capitan. For this reason, it is an EDRR target, and I ask that you be on the lookout for this weed and report it to the Agricultural Commissioner when found.

24 Geraldton carnation spurge

25 Artichoke thistle March 2005 March 2010 Artichoke thistle, the wild relative of the edible globe artichoke, occurs on the Gaviota Coast. Artichoke thistle can create monocultures and is extremely spiny. Cattle, horses, and wildlife don t eat it and thus rangeland value is significantly reduced. I am trying to eradicate the weed on three contiguous properties. Here are pictures. Two consecutive years, 2009 and 2010, of treatment with aminopyralid and/or glyphosate.

26 Artichoke thistle March 2005 March 2010

27 Purple starthistle Purple starthistle is a vicious, spiny plant with a bitter taste, that cattle, horses and wildlife avoid grazing. In Santa Barbara County, it can be found as a rangeland pest from Las Cruces to Lompoc. It has been recorded near Santa Maria and Summerland and was found in Los Alamos in the early 1950s. Purple Starthistle Asteraceae: Centaurea calcitrapa CDFA B rated; CalEPPC B rated Purple starthistle is a vicious, spiny plant with a bitter taste, that cattle, horses and wildlife avoid grazing. The species name, "calcitrapa", is derived from the word caltrop, a weapon used to hinder the movement of tanks and calvary in ancient and modern times. In Santa Barbara County, it can be found as a rangeland pest from Las Cruces to Lompoc. It has been recorded near Santa Maria and Summerland and was found in Los Alamos in the early 1950s. Purple starthistle is biennial thistle, but may be an annual or short-lived perennial under some conditions. It has a mounding growth habit with purple flower heads with sharp, stiff spines. The plant can break at ground level, dispersing the seeds much like a tumbleweed. Small infestations can be controlled by grubbing or digging -- cutting the plant, two inches below the soil surface, early in the growing season. Clopyralid, glyphosate, 2,4-D and dicamba have been effective in controlling this weed. Mowing is not effective.

28 Russian knapweed A noxious perennial species that exhibits allelopathic effects and is aggressively competitive, facilitating rapid colonization and development of dense stands. Infestations can be extremely long-lived due to extensive root and rhizome systems. Like yellow starthistle [Centaurea solstitialis L.], Russian knapweed is toxic to horses, causing nigropallidal encephalomalacia or "chewing disease" when sufficient quantities are consumed. Under most circumstances livestock will avoid grazing Russian knapweed because of its bitter taste.

29 Before and after pics

30 Silverleaf nightshade Toxic to livestock, people. Able to create dense patches. Reduces rangeland production.

31 Onionweed Onionweed is an unpalatable invasive plant that can reduce rangeland value. This plant occurs along the sides of Hwy 101 and 154 and is just starting to show up on Hwy 1 between Gaviota and Lompoc. It is important to not use contaminated mowers on uninfested roadsides.

32 Pampasgrass Pampasgrass is an invasive weed that can create monocultures and reduce habitat and rangeland value. It can dominate a landscape and increase the fire risk.

33 Pampasgrass Cortaderia selloana Common garden escape Reduces habitat quality Fire hazard Reproduces from seed, wind-blown Soon spreading to your area, pampas grass is an example that is still being sold in nurseries but is causing problems as a common garden escape. Pampas grass should be propagated by division. The grass is dioecious and the female plant is the showier plant. Unfortunately, some nurseries have propagated it from seed and male plants, which are very difficult to distinguish, have also escaped into the environment. Reproduction and Spread Pampas Grass Pampas grass is typically propagated for ornamental purposes through division of mature plants. In recent years some nurseries have propagated pampas grass from seed. Since it is impossible to distinguish male from female plants before they flower, the result is an increase in the proportion of male plants in the population. Consequently, there has been an increase in the amount of viable seed produced, and this species has escaped to become an invasive weed along the California coast. The species is considered gynodioecious, that is, flowers of some plants consist of both male and female parts on the same flower, but only the male parts are functional. Other plants bear only female flowers. Thus, this species is functionally dioecious. Over the years, selection for ornamental plants in California has been for the showier plumes of the female plants. can also reproduce vegetatively from fragmented tillers that produce adventitious roots in moist soils. Jubata Grass all plants produce only female flowers. numerous seeds produced apomictically (without pollen transfer). An individual inflorescence can produce 100,000 minute seeds, and large clumps can produce a million or more seeds. Like Cortaderia selloana, jubata grass can also reproduce vegetatively from fragmented tillers that produce adventitious roots in moist soils. Spread occurs by wind-blown seed or by humans using mature inflorescences in decorative arrangements or using plants in landscaping. Seeds have been reported to disperse over twenty miles under windy conditions. Movement throughout the state also occurs when nurseries mistakenly sell this weedy species instead of Cortaderia selloana. Problems Although the more aggressive Cortaderia jubata is often called pampas grass, true pampas grass (C. selloana) can also be weedy in California. In other areas of the world, particularly New Zealand and Australia, C. selloana is an important weed problem in forestry operations and conservation areas (Gadgil et al. 1984, Harradine 1991). In forests it competes with seedling trees and can slow their establishment and growth. Pampas grass creates a fire hazard with excessive build-up of dry leaves, leaf bases, and flowering stalks. In addition, heavy infestations can block access to plantations and pose a significant fire hazard. In conservation areas pampas grass competes with native vegetation, reduces the aesthetic and recreational value of these areas, and also increases the fire potential.

34 Some of you may travel Las Positas Rd frequently. Caltrans recently assisted me in a project I conducted in the area. A backhoe is an effective way to control pampas grass.

35 Centaurea solstitialis Yellow Starthistle Spiny stage Wildlife, cattle, avoid it. Recreation inhibited. Chewing disease in horses Depletes soil moisture Displaces native plants Crop weed Some of you may be familiar with yellow starthistle, especially if you enjoy hiking in the Los Padres or if you drive up Mountain Rd. YST is considered one of the most serious pests of rangeland and has nearly taken over the West. YST is poisonous to horses causing a neurologic disease called nigropallidial enchepalomalacia or chewing disease. This disease is expressed as a twitching of the lips, tongue flicking, and involuntary chewing. Permanent brain damage is possible, and affected horses may starve to death. Asteraceae: Centaurea solstitialis CDFA C rated; CalEPPC A-1; is considered one of the most serious rangeland weeds in the western U.S. Plants are highly competitive and typically develop dense, impenetrable stands that displace desirable vegetation in especially in rangeland HABITAT: Open, disturbed sites, grasslands, rangeland, open woodlands, fields, pastures, roadsides, waste places. Yellow and Malta starthistle also occur in cultivated fields. typically found in full sunlight and deep, well-drained soils, where annual rainfall is between inches. less commonly encountered in the desert, high mountains and moist coastal sites. Problems - Losses probably occur from interference with livestock grazing and forage harvesting procedures, and lower yield and forage quality of rangelands. Because of the spiny nature of yst, livestock and wildlife avoid grazing in heavily infested areas. Although the nutritional component of yellow starthistle leaves is high during the growing season, its nutrient value declines as the plants mature. Yellow starthistle in the pre-spiny stage contains between 8 to 14% protein. However, an analysis of the nutritional status of cattle manure in the fall indicated that yellow starthistle-infested pastures contain considerably less crude protein and total digestible nutrients compared to uninfested pastures. Chewing disease cumulatively poisonous in horses causing nigropallidial encephalomalacia. Unknown chemical component only affects horses and permanently damages the area of the brain that controls fine motor movements, including mouth and lip movements. Toxicity effects are cumulative. Horses must consume a % of an animal s weight in dry-weight plant material over a period of 1 to 3 months to produce symptoms. Because of its bitter taste, horses usually avoid grazing yellow starthistle, but some horses develop a taste for it. The disease can occur when horses are allowed to graze infested pastures, especially those that lack adequate amounts of suitable green forage, or are fed contaminated hay over a period of time. Once the toxicity threshold has been reached, symptoms occur rapidly. Symptoms include fatigue, lowered head, an uncontrolled rapid twitching of the lower lip, tongue-flicking, involuntary chewing movements, and an unnatural open position of the mouth. Without intervention, affected horses are unable to eat or drink and eventually die from starvation or dehydration Additional detrimental effects: Less nutritional, Crop weed (hay, cereals, orchards, vineyards), Displaces native vegetation, Depletes soil moisture. However, is a good honey plant

36 Seedhead Flies Currently Used for Biological Control of Yellow Starthistle Urophora siruneseva YST gall fly introduced 1984 Chaetorellia succinea False Peacock fly introduced 1991 Chaetorellia australis Peacock fly introduced 1988 As it is so widespread, biological control is the last salvation in many areas. More active management may be called for in areas where it does not occur as widely, like in western Santa Barbara County. Here are three flies that have been released to control YST. These flies feed on the seedheads of YST. They are mostly specific to YST. The false peacock fly is the most effective.

37 Weevils Currently Used for Biological Control of Yellow Starthistle Bangasternus orientalis YST Bud Weevil introduced 1985 Eustenopus villosus Hairy Weevil introduced 1990 Larinis curtis YST Flower Weevil introduced 1991 Here are three beetles that have been released. The hairy weevil is considered the most effective.

38 Fountaingrass Fountaingrass interferes with native plant diversity and fire regimes. It seems to be less prevalent along Hwy 1.

39 How can you help?

40 How can you help? Control noxious and invasive weeds that might exist on your property. Report Early Detection targets Control noxious and invasive weeds that might exist on your property. This weed is known as onion weed or Asphodelus fistulosus. It is a federal noxious weed that is proliferating on roadsides in this area and is rapidly spreading. It is also unique in being a wildland weed being domesticated by those who like the flower.

41 How can you help? Clean your shoes, vehicles and gardening equipment after working in weed infested areas.

42 Thank You! What Can You Do to Help Management Control noxious weeds found in your jurisdiction. Use integrated management techniques to minimize impacts on the environment and public health. Surveillance Assist the Weed Management Area by reporting infestations of exotic weeds. Map the infestations on your property and prevent spreading the weeds to other areas. Prevention Use weed free seed and mulches. Map the current infestations of noxious weeds in your jurisdiction and clean equipment used in those areas before using them in uninfested areas. Train your staff in the recognition of noxious weeds and on the principles of weed management and especially on preventing their spread. We can help you. The Santa Barbara County Weed Management Area exists to help the public deal with the invasive exotic weeds. We will gladly help where we can.

43 To learn more Contact: County of Santa Barbara Agricultural Commissioner California Dept of Food & Agriculture - Encycloweedia The California Invasive Plant Council