Several insect biological control agents targeting
leafy spurge have been introduced from Europe to North America (Bourchier et al., 2006).
Using this survey method, called Very Large Scale Aerial (VLSA) imagery, Agricultural Research Service rangeland specialist Terry Booth and colleagues discovered that
leafy spurge was displacing sagebrush seedlings.
This happened when the Hyles euphorbiae, a pink-hued hawk moth, was introduced in the 1960s to combat
leafy spurge, a Eurasian perennial now present in 19 states and seven national parks.
Examples include quackgrass and Johnson grass (both have rhizomes);
leafy spurge and Canada thistle (both have creeping roots); and bermuda grass (has stolons).
Over a two-year period, my colleagues Ron and Margaret Royer and I have studied the effects of one invasive plant species,
leafy spurge, on pollination of its native neighbors and on the insect communities that visit native flowers.
"We no longer have to use herbicides to control
leafy spurge, and crop production has increased." Dennis Thaler reports.
For example,
leafy spurge (Euphorbia esula) exposed experimentally to millimolar concentrations of HQ had reduced water uptake by leaves, resulting in closed stomata and decreased photosynthesis (1).
"
Leafy spurge can survive almost anywhere," said Chad Prosser, liaison for the Northern Great Plains Exotic Plant Management Team, responsible for ridding 14 national parks of noxious and invasive weeds.
The weeds include yellow star thistle,
leafy spurge, Japanese knotweed and false brome.
What's hot: BASF's Professional Vegetation Management Group: control of invasive weeds--cheatgrass and
leafy spurge; land restoration; tools for minimizing wildfire impact; control of sandbur and grass weeds in bermudagrass pastures; new product information.
Leafy spurge can be found in at least 36 states and costs more than $144 million annually for control measures and in loss of grazing land in Montana, North Dakota, South Dakota and Wyoming.
Leafy spurge and spotted knapweed are common examples of accidentally introduced weeds.
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Leafy spurge, a rapidly spreading invasive shrub is choking out the western prairie fringed orchid in the Sheyenne National Grasslands of North Dakota and possibly in other areas; herbicides used to control spurge can kill the orchid as well.
Put another way, the benefits of cattle do not lessen the damage wrought by
leafy spurge and cheatgrass.
ASSESSMENT OF BIOLOGICAL CONTROL AGENTS FOR AREA-WIDE INTEGRATED PEST MANAGEMENT OF
LEAFY SPURGE IN MONTANA AND SOUTH DAKOTA.
