Description:
Roots:
Reddish brown that contain pink-colored buds at the crown (top of root, just below surface) when the top growth is removed, new shoots will develop from the buds (1). The roots are thick and corky looking that allow it to survive during drought and periods of chemical treatment (7). They will penetrate to approximately 15 feet horizontally and 40 feet vertically (7). It is a perennial (grows back every year from the roots) (2).
Stems/Leaves:
The stems can be 3/4 foot to 4 feet tall (2); it contains a milky sap that is toxic to many animals (1). The stem growth starts in April (3). The leaves are 1 to 4 inches long, narrow, and bluish-green in color (1), although they turn yellowish or reddish-orange in late summer (3). The leaves are also hairless and have a very thick layer of cutin (waxy substance) on it (7).
Flowers:
The flowers come from petal-like structures called bracts (the cover of the flower that holds it to the stem) (1, 2). The yellow bracts appear in May (3). Three to eight days after its pistil stigmas open up and are available to pollen the glands begin to secrete nectar that is orange and sticky when ripe (7).
Seeds/Fruit:
Seeds grow in the pods on top of the bract (1, 3). The pod is the fruit. When mature, the pods burst open and throw seeds up to 15 feet from its parent plant (3). Each stem can produce 150 to 200 seeds. (7) There can be up to 350 to 1,000 seeds per sq. ft. (7). The seeds can germinate (grow) up to 8 years after thrown from is parent plant (3). For the seeds to grow there must be at least a weeks worth of days that are 78 to 82 degrees (7). They are smooth, oblong, and light gray to dark brown in color (1). To check the maturity of a seed you can break its fruit open and look at the color of it (it is dark when mature) (7).
Methods of Reproduction/Spread:
Reproduction occurs by the regrowth from spreading roots and also by the production of large amounts of seeds spread by birds, wildlife, humans, and rivers and streams (4). They spread from spreading roots, production of large amounts of seeds, and by the shooting of seeds off of its parent plant (1-4). Thus, each year plants can grow up to 15 feet away from the origional patch of spurge; this makes it hard to keep it from spreading and to get rid of it each year (7).
Life Style/Habits/Life Duration:
Leafy spurge begins its growth each year in early spring (5). It grows from the buds on the crown, roots, and from the seeds (5). In late April, in the northern climates, the buds on the roots usually begins to grow. The period of seed germination in the northern climates is late May to early June. 20 to 30 days after flowering the seeds develop (5). It will usually grow where there is the least opposition from native plants (8).
Montana infestation/history:
It occurs in every county in Montana (2).
Environments favorable to infestation:
Both dry and wet climates are homes of leafy spurge (2). It is found in continental Europe to southern countries like Spain, the Balkans, and Italy (7). Montana, Idaho, Wyoming, and North and South Dakota have the most infested US states and with Canada's provinces it infests over 2.7 million acres of land in the Great Plains (7). It will also grow in subtropical to subartic regions (7).
Impacts:
Decreases native plant life, increases erosion, and sap is toxic to animals (2). The milky latex is poisonous to some animals and can cause irritation on skin (4). In cattle it causes scours and weaknesses; if eaten in large amounts it can cause death (4). In 1995, the cost of control in Montana, North and South Dakota, and Wyoming was at an estimated 144,350,000 dollars (6). The average cost per year to battle it is over $110 million (9). In North Dakota it costs $11 million annualy to fix recreational areas and wildlife habitat (9).
Comments:
Leafy spurge is a huge problem that gets bigger all the time (2). It is difficult to kill or control by chemicals and basically impossible to control by cultural or physical methods (4). However, sheep and goats can be taught to eat it and will have an impact on infestations (4).
Native Range/Probable Entry Into N. America:
Native to Europe and Asia (6). It was introduced from Eurasia in 1827 (3). It was found in North Dakota in 1909 (7).
Methods of control:
You will usually want to use these in some sort of combination with one another (8).
Chemical
:
You want to use chemicals that will leave behind the least amount of toxic residue (10). The best long-term control strategy is to use a herbicide treatment program that uses annual applications (5). Fall treatments control well-established leafy spurge plants quite effectively (3). For leafy spurge, Tordon is the most effective herbicide to use (3). For best results, use a gallon of Tordon per acre in the spring, during flowering development (3).
Cultural
:
This type of management is often used on cropland. There are two types of cultivation for leafy spurge, they are intensive throughout the growing season and fall-only cultivation (5). Intensive cultivation programs should begin two to four weeks after leafy spurge emerges, generally in the spring (5). You should till at least four inches deep every three weeks until the soil freezes for one or two years (5). Fall only cultivation should be done when the regrowth of leafy spurge is three to six inches tall for three years (5). You should do this once or twice a year. This allows crops to grow during the season and reduces soil erosion (5).
Grazing:
We also use goats and sheep because they will eat it and not get sick (11). To do this you will want to fence them off where you want them to graze (11). By using this method you out more stress on the plants root system (11). This provides a big risk that the seeds will get into the fur or hooves of the sheep or goats if you are grazing during the mature seed stage (11).
Biological:
Fifteen species of European insects have been tested, imported and are being used for leafy spurge control in the United States (6). The most effective biocontrol agents are several species of root- and foliage-feeding beetles with the genus name
Aphthona
and one species of stem- and root-boring beetle,
Oberea erythrocephala
(5). Biocontrol agents will never completely exterminate leafy spurge from an area, but they may reduce weed populations over a period of years (5). Use the links next to the description below to find out more about the insect you are looking for. The types of insects used to control leafy spurge is as follows:
Aphthona abdominalis-
gray to straw colored, measures about 2.0mm long by 1.0mm wide, live up to 40 to 55 days.
http://mtwow.org/Aphthona-abdominalis.html
Aphthona cyparissiae-
are oval and brown, measures 3.2mm long.
http://mtwow.org/Apothona-cyparissiae.html
Aphthona czwalinae-
are black, males measure 2.9mm in length and the females are 3.1mm.
http://mtwow.org/Aphthona-czwalinae.html
Aphthona flava-
coppery looking, male measures about 3.4mm long and the females 3.6mm long
.
http://mtwow.org/Aphthona-flava.html
Aphthona lacertosa-
is black, 3mm long, produce up to 200 to 300 eggs.
http://mtwow.org/Apthona-laceratosa.html
Aphthona nigriscutis-
are brown with a black dot on their thorax, 3mm to 3.5mm long, lay up to 400 eggs a year.
http://mtwow.org/Aphthona-nigriscutis.html
Chamaesphecia crassicornus-
10 to 14mm long, usually dark brown with yellow markings, wings are clear.
http://mtwow.org/Chamaesphecia-crassicornus.html
Chamaesphecia hungarica-
10 to 14mm long, black abdomen,the outer wings are 7 to 10mm, looks like a "cross between a bee and moth."
http://mtwow.org/Camaesphecia-hungarica.htm
Chamaesphecia tenthrediniformis-
black bodies and yellow scaled wings, wingspan 13 to 30mm, resembles
C. empiformis.
http://mtwow.org/Chamaesphecia-tenthrediniformis.html
Dasineura sp. nr. capsulae-
females live up to 3 days when becoming an adult, and the males live up to 2.4 days when becoming an adult, they have reddish yellow bodies with brown hardened parts, females are 2.3mm long and 0.4mm wide, and the males are1.7mm long and 0.02mm wide
.
http://mtwow.org/Dasineura_sp_nr_capsulae_leafy_spurge_gall_midge.html
Hyles euphorbiae-
25 to 30mm long, wingspan 5cm, furry brown and very distinctive wings
http://mtwow.org/Hyles-euphorbiae.html
Oberea erythrocephala-
10 to 12mm in length, have antennae, gray and have a reddish orange head
http://mtwow.org/Oberea-erythrocephala.html
Spurgia esulae-
very small and delicate, lives only a matter of hours, looks like a fly.
http://mtwow.org/Spurgia-esula.html
Other:
Other controls of leafy spurge may be as follows: mowing and burning, pulling by hand, plant competition, reduction, and eradication (11). For reducing leafy spurge infestations, mowing and burning are ineffective. Although, it may provide a more effective herbicide treatment (5). For best results, allow five weeks of regrowth before applying herbicide applications (5). To reduce seed production, mow every two to four weeks during growing season (5). Even for small, isolated patches, pulling by hand is very ineffective because of the deep root system (5). Perennial grass species can effect the supply of moisture and nutrients to the plants (5). Reduction is where you take out the dominance of the plant, but it takes time and money (11). By using the eradication method you get rid of it on your land (11).
How to Prevent Spread
:
Use weed seed free hay, isolate animals for a week that were in an infested area so that all the seeds can go through the animals body, wash the under carriage of vehicles in a commercial area making sure all seedlings; stems; flowers; etc. are washed down the drain, and don't get soil or gravel from an area infested with leafy spurge (2).
Bibliography:
1.) Jackson, M.J., Baker, L.O., Cooperative Extension Service Montana State University Bozeman, Montana, on file at Whitehall High School.
2.) Breitenfeldt, Todd, Personal Interview, Biology Teacher, Whitehall School, Box 1109, Whitehall, Mt 59759. (406) 287-3862. 9-1-99.
3.) Moomaw, R.S., et., al., Ed., Leafy Spurge. [Online] Available http://www.ianr.unl.edu/pubs/Weeds/g834.htm, revised February 1989, 2/3/99.
4.) Rees, Norman, et. al., Ed., Biological Control of Weeds in the West, Western Society of Weed Science, in cooperation with USDA ARS, MT Dept. of Ag, and MT State Univ., Color World Printers, Bozeman, MT, Feb., 1996.
5.) Lujeunesse, Sherry. et., al., Ed., 1995, Leafy Spurge; Biology, Ecology and Management, Pamphlet, EB 134, July 1995, Montana State University, Bozeman, Montana 59759.
6.) Spencer, Neal R., Insects Up-Plants Down: Towards Control of Leafy Spurge,
Euphorbia esula
L. On The Great Northern Plains, [Online] Available, http://ext.agn.uiuc.edu/abstract/145.html, Updated February 1997, 9/29/99.
7.) Messersmith, C.G. "The Leafy Spurge Plant"
Purge Spurge
. 1995 ed. CD-ROM. Bozeman,MT. USDA Agricultural Research Service In Cooperation with Montana State University.1995.
8.) Beck, K.G. "leafy spurge".2005. ext.colostate.edu. 14 January 2006 http://www.ext.colostate.edu/pubs/natres/03107.html
9.) Muller et al., "Damage".2000. efn.org. 13 January 2006 http://www.efn.org/~ipmpa/index.shtml. updated August 20, 2000.
10.) Lajuenesse et al. "Leafy Spurge: Biology, Ecology, and Management". July. 1995: EB 134.
11.) Sedivec et al., "leafy spurge".2000. efn.org., 13 January 2006 http://www.efn.org/~ipmpa/index.shtml .
By:
Sarah Stratton
11/99.
Edited By:
Mike Roylance
11/99.
Updated By:
Bryan Krueger 2-16-2006.
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