PERMFILE128898

• Permit No: C1980001
• IBM Index Class Name: Permit File
• Doc Date: 3/20/2006
• Doc Name: Weed Management Plan
• Section_Exhibit Name: 4.4 Appendix 4.4-G
• Media Type: D
• Archive: No

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Figure 2: Leafy spurge (Euphorbia esula
L.)
Biological control. Sheep or goats can be used to help
control leafy spurge. Research from Montana State University
indicates sheep may consume up to 50 percent of their diet as
leafy spurge. Introduce sheep to leafy spurge in early spring
when the weed is succulent Goats will consume leafy spurge at
almost any time during the growing season.
Rotate pastures to prevent seed production and allow
desirable forage plants to regain vigor. If livestock graze leafy
spurge after seed formation, hold animals in a corral for a[ leas[
seven days before moving them to an uninfected area. This
reduces viable seed passage. Sheep or goats followed by fall
herbicide treatment may be an effective, integrated means to use
infested ground and control the weed.
The USDA is examining several insects for leafy spurge
control. The Colorado Department of Agriculture Insectary has
four flea beetles (Apthona nigriscutis, black-dot flea beetle; A
cyparissiae, brown-dot spurge flea beetle; A czwalinae, black
spurge flea beetle; and A. flava, copper spurge flea beetle)
available for release. Their larvae feed on leafy spurge root hairs
and within roots, while adults feed on foliage. Other insects may
become available in the future. Most likely, a combination of
insects will be necessary to adequately control leafy spurge.
Insects would be most advantageous in areas where herbicide
use is difficult or risky.
Recent research completed by Colorado State
University showed that six to eight sheep per acre grazing for ] 0
days in July over a period of five years decreased leafy spurge density about 90
percent. When flea beetles grazed simultaneously in July with eight sheep per
acre for 10 days over five years, leafy spurge density was decreased to zero.
Habitat requirements of the flea beetles vary. While all requirements are
not well understood, it is known that A. nigriscutis prefers open, dry sites and
coarse soils low in organic matter. A. cyparissiae prefers soils higher in moisture
than A. nigriscutis, but still prefers moderately coarse-textured soils such as
sandy ]oams and open sites. A. Flava does well in coarse soils with high water
tables in open and shaded conditions. A. czwalinae prefers moist, clay soils.
Regazdless of the management system used, a combination of methods is
essential to return leafy spurge-infested ground to a productive state. The key to
control leafy spurge or any creeping perennial is to exhaust the root nutrient
stores, causing it to collapse. Persistence is imperative to gain control.
Issued rn furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in
'Colorado State University Cooperative cooperation with the U.S. Department of Agriculture, Milan A. Rewens, Director of Cooperative
Extension weed science specia/ist and Extension, Colorado State University, Fort Collins, Colorado. Cooperative 6dension progrems are
professor, bioagncultural sciences and pest available to all without discrimination. No endorsement of products mentioned is intended nor is
management. criticism implied of products not mentioned.