Purple Starthistle Fact Sheet

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Purple Starthistle Fact Sheet Centaurea calcitrapa Asteraceae Family Barry Rice, sarracenia.com, Bugwood.org D. Walters and C. Southwick, Table Grape Weed DPI Victoria Disseminule ID, USDA APHIS ITP, Bugwood.org Distinguishing Features: Flowers: The flowers are purple and 0.6 to 1 inches in diameter. Twenty-five to 40 florets (small flowers) make up each flower head. Underneath the flower are spine-tipped bracts that are greenish or straw-colored. Seeds: The seeds are oblong and 2.5-3.5 mm long. They are white and often streaked with brown. Leaves: The leaves are alternate, with deeply divided lower leaves and narrow and undivided upper leaves. The leaves are five to eight inches long and have dots of resin on their surfaces. Flowering Time: The plant produces long stems in spring and early summer. It flowers from June through November. Life cycle: Purple Starthistle can live as an annual in extremely favorable conditions, but most often lives as a biennial. Impacts: ➢ Purple Starthistle can quickly displace native flora in disturbed areas due to its rapid growth and seed production. ➢ Purple Starthistle is unpalatable to grazing animals and rapidly degrades the forage quality in any infested areas. ➢ With thicker and stronger spines than its relatives, Purple Starthistle poses a threat of injury to both humans and animals moving through infested areas. K. Mosbruger, SLCO Weed Control Program Control: ➢ Small infestations of Purple Starthistle can be effectively controlled by manually pulling and disposing of plant remains. Plants should be cut at least 2 inches below the surface. ➢ There are no effective biocontrol agents currently approved for use in the US to control Purple Starthistle. ➢ Chemical control can prove effective on Purple Starthistle if applied in early spring. Multiple treatments Salt Lake County Weed may be needed for best control. Control Program www.slco.org/weeds/ 385-468-4035 [email protected] *Please visit our website for references sourcing this information. .

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Caution Restricted Use Pesticide
RESTRICTED USE PESTICIDE May Injure (Phytotoxic) Susceptible, Non-Target Plants. For retail sale to and use only by Certified Applicators or persons under their direct supervision and only for those uses covered by the Certified Applicator's certification. Commercial certified applicators must also ensure that all persons involved in these activities are informed of the precautionary statements. DOC ID 551929 June 23, 2017 For control of annual and perennial broadleaf weeds, woody plants, and vines on CAUTION • forest sites, conifer plantations • non-cropland areas including, but not limited to, Agricultural Use Requirements airports, barrow ditches, communication transmission Use this product only in accordance with its labeling and with lines, electric power and utility rights-of-way, fencerows, the Worker Protection Standard, 40 CFR part 170. Refer to label gravel pits, industrial sites, military sites, mining and booklet under "Agricultural Use Requirements" in the Directions drilling areas, oil and gas pads, parking lots, petroleum for Use section for information about this standard. tank farms, pipelines, railroads, roadsides, storage For additional Precautionary Statements, First Aid, Storage and areas, substations, unimproved rough turf grasses, Disposal and other use information see inside this label. • natural areas (open space), for example campgrounds, parks, prairie management, trails and trailheads, Notice: Read the entire label. Use only according to label recreation areas, wildlife openings, and wildlife habitat directions. Before using this product, read Warranty Disclaimer, Inherent Risks of Use, and Limitation of Remedies at end and management areas of label booklet. If terms are unacceptable, return at • including grazed or hayed areas in and around these sites once unopened.
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Squarrose Knapweed EXOTIC Centaurea Virgata Ssp
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Weed Risk Assessment: Centaurea Calcitrapa
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Thistle Identification Referee 2017
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Proceedings of the X International Symposium on Biological Control of Weeds 747 4-14 July 1999, Montana State University, Bozeman, Montana, USA Neal R. Spencer [ed.]. pp. 747-751 (2000) Population Buildup and Combined Impact of Introduced Insects on Yellow Starthistle (Centaurea solstitialis L.) in California MICHAEL J. PITCAIRN1, DALE. M. WOODS1, DONALD. B. JOLEY1, CHARLES E. TURNER2, and JOSEPH K. BALCIUNAS2 1California Department of Food and Agriculture, Biological Control Program, 3288 Meadowview Road, Sacramento, California 95832, USA 2United States Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, USA Abstract Seven exotic seed head insects have been introduced into the western United States for control of yellow starthistle. Six are established; three are widespread. Preliminary evaluations suggest that no one insect species will be able to reduce yellow starthistle abundance in California. Rather, a combination of the current, and possibly, future natu- ral enemies may be necessary. Studies were initiated in 1993 to evaluate the population buildup, combined impact, and interaction of all available biological control insects on yellow starthistle. Three field sites were established in different climatic regions where yellow starthistle is abundant. Four insects, Bangasternus orientalis, Urophora sirunase- va, Eustenopus villosus, and Larinus curtus, were released at each site in 1993 and 1994 and long-term monitoring was initiated. The accidentally-introduced insect, Chaetorellia succinea, was recovered in 1996-98 at these sites. Four years after the first releases, we have evidence that these biological control agents are having an impact on yellow starthistle seed production that may translate into a decline in mature plant populations.
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(Centaurea Stoebe Ssp. Micranthos) Biological Control Insects in Michigan
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Valparaiso University The Great Lakes Entomologist Volume 47 Numbers 3 & 4 - Fall/Winter 2014 Numbers 3 & Article 3 4 - Fall/Winter 2014 October 2014 Establishment, Impacts, and Current Range of Spotted Knapweed (Centaurea Stoebe Ssp. Micranthos) Biological Control Insects in Michigan B. D. Carson Michigan State University C. A. Bahlai Missouri State University D. A. Landis Michigan State University Follow this and additional works at: https://scholar.valpo.edu/tgle Part of the Entomology Commons Recommended Citation Carson, B. D.; Bahlai, C. A.; and Landis, D. A. 2014. "Establishment, Impacts, and Current Range of Spotted Knapweed (Centaurea Stoebe Ssp. Micranthos) Biological Control Insects in Michigan," The Great Lakes Entomologist, vol 47 (2) Available at: https://scholar.valpo.edu/tgle/vol47/iss2/3 This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. For more information, please contact a ValpoScholar staff member at [email protected]. Carson et al.: Establishment, Impacts, and Current Range of Spotted Knapweed (<i 2014 THE GREAT LAKES ENTOMOLOGIST 129 Establishment, Impacts, and Current Range of Spotted Knapweed (Centaurea stoebe ssp. micranthos) Biological Control Insects in Michigan B. D. Carson1, C. A. Bahlai1, and D. A. Landis1* Abstract Centaurea stoebe L. ssp. micranthos (Gugler) Hayek (spotted knapweed) is an invasive plant that has been the target of classical biological control in North America for more than four decades.
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DIFFUSE KNAPWEED (Centaurea Diffusa)
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t I:iiW 12.5 I:iiW 1.0 W ~ 1.0 W ~ wW .2 J wW l. W 1- W II:"" W "II ""II.i W ft ~ :: ~ ........ 1.1 ....... j 11111.1 I II f .I I ,'"'' 1.25 ""11.4 111111.6 ""'1.25 111111.4 11111 /.6 MICROCOPY RESOLUTION TEST CHART MICROCOPY RESOLUTION TEST CHART I NATIONAL BlIREAU Of STANDARDS-1963-A NATIONAL BUREAU OF STANDARDS-1963-A I~~SECTS AND FUNGI ;\SSOCIATED WITH (~ARDUUS THISTLES (COMPOSITAE) r.-::;;;:;· UNITED STATES TECHNICAL PREPARED BY • DEPARTMENT OF BULLETIN SCIENCE AND G AGRICULTURE NUMBER 1616 EDUCATION ADMINISTRATION ABSTRACT Batra, S. W. T., J. R. Coulson, P. H. Dunn, and P. E. Boldt. 1981. Insects and fungi associated with Carduus thistles (Com positae). U.S. Department of Agriculture, Technical Bulletin No. 1616, 100 pp. Six Eurasian species of Carduus thistles (Compositae: Cynareael are troublesome weeds in North America. They are attacked by about 340 species of phytophagous insects, including 71 that are oligophagous on Cynareae. Of these Eurasian insects, 39 were ex tensively tested for host specificity, and 5 of them were sufficiently damf..ghg and stenophagous to warrant their release as biological control agents in North America. They include four beetles: Altica carduorum Guerin-Meneville, repeatedly released but not estab lished; Ceutorhynchus litura (F.), established in Canada and Montana on Cirsium arvense (L.) Scop.; Rhinocyllus conicus (Froelich), widely established in the United States and Canada and beginning to reduce Carduus nutans L. populations; Trichosirocalus horridus ~Panzer), established on Carduus nutans in Virginia; and the fly Urophora stylata (F.), established on Cirsium in Canada.
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