| Euphorbia virgata | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Euphorbiaceae |
| Genus: | Euphorbia |
| Species: | E. virgata |
| Binomial name | |
| Euphorbia virgata Waldst. & Kit.,1803 | |
Euphorbia virgata, commonly known as leafy spurge, wolf's milk leafy spurge, or wolf's milk is a species of spurge native to Europe and Asia, and introduced in North America, where it is an invasive species. [1]
It has commonly been confused with Euphorbia esula , a species no longer considered a permanent component of the North American flora. Euphorbia esula is restricted to certain parts of Europe and not considered a weedy species, while E. virgata is found throughout the United States and Canada and has caused significant economic and ecological impacts. [1] E. virgata is best distinguished from E. esula by its leaves, which are 6-15 times longer than wide with margins that are (near-)parallel at the middle of the blade, while E. esula leaves are wider toward the tip, usually 3-8 times longer than wide, with margins that are not parallel at the middle of the leaf. In addition, the apex of E. virgata is usually acute and the base is truncate to attenuate, while the apex of E. esula is rounded or subacute and the base is more gradually attenuate or cuneate. [1] Mentions of E. esula in the North American flora and invasive species literature are now referred to E. virgata.
Leafy spurge was transported to the United States possibly as a seed impurity in the early 19th century. It now occurs across much of the northern U.S., with the most extensive infestations reported for Montana, North Dakota, Nebraska, South Dakota, and Wyoming. Since the introduction of leafy spurge to the United States, it has been found in 458 counties in 26 states. [2] It has been identified as a serious weed on a number of national parks and on reserves of The Nature Conservancy in eleven northern states. It is now classified as an invasive species by the United States Department of Agriculture. [3] [4]
Leafy spurge grows in a variety of different climate environments. [5] It displaces native vegetation in prairie habitats and fields through shading and by usurping available water and nutrients and through plant toxins that prevent the growth of other plants underneath it. It is an aggressive invader and, once present, can completely overtake large areas of open land. Leafy spurge quickly colonizes in areas with bare soil, especially those caused by human disturbance where native species are removed. One method of control suggested is to limit the amount of bare soil from these disturbances. [6] It is toxic as well. [3]
Because of its persistent nature and ability to regenerate from small pieces of root, leafy spurge is extremely difficult to eradicate. In Saskatchewan, leafy spurge spread on trails used by settlers and traders. More recently, the travel of leafy spurge has been linked to railroads and the use and transport of infested hay used for agriculture. [2] Biological control offers a highly promising management tactic for leafy spurge. Goats, apparently able to graze on the plant without ill effect, have been used on rail trails in Idaho to clear leafy spurge from the trail shoulders. [7] Sheep have been used in North Dakota, along with herbicides and flea beetles, to fight it. [8] The U.S. Department of Agriculture has shown success using six European insects that feed on leafy spurge. These include a stem and root-boring beetle ( Oberea erythrocephala ), five root-mining flea beetles ( Aphthona spp.), [9] the Spurge Hawk-moth ( Hyles euphorbiae ), [10] and a shoot-tip gall midge ( Spurgia esulae ). Large scale field-rearing and release programs are carried out cooperatively by federal and state officials in many northern U.S. states. The results are not as immediate as when herbicides are used but, if pesticide use is kept to a minimum, large numbers of these insects build up within a few years and have shown impressive results. [3]
Several systemic herbicides have been found to be effective if applied in June, when the flowers and seeds are developing, or in early-to-mid-September, when the plants are moving nutrients downward into the roots. Preliminary research suggests that chemical treatment in the fall followed by a spring burn to reduce seed germination may be an effective strategy for reducing leafy spurge infestations. Multiple treatments are necessary every year for several years, making leafy spurge control an extremely expensive undertaking. [11] If left uncontrolled for a single year, leafy spurge can reinfest rapidly. Prescribed burning, in conjunction with herbicides, may also be effective. [3]
Leafy spurge is being developed as a model to answer fundamental questions of weed biology. Over 55,000 expressed sequence tags have been sequenced from all plant tissues including tissues from plants that were cold stressed, drought stressed, or attacked by both flea beetles and gall midges. Analysis of the EST sequences indicated that 23,000 unique sequences representing more than 19,000 unigenes were obtained. These sequences are now available on Genbank. The unigenes have been used to develop cDNA microarrays that also include more than 4,000 additional cDNAs from cassava (another Euphorb related to leafy spurge). These microarrays are being used to identify physiological processes and signals that regulate bud dormancy (one of the main reasons leafy spurge is difficult to control) [12] and invasiveness.
Euphorbia is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae, not just to members of the genus.
Weed control is a type of pest control, which attempts to stop or reduce growth of weeds, especially noxious weeds, with the aim of reducing their competition with desired flora and fauna including domesticated plants and livestock, and in natural settings preventing non native species competing with native species.
Euphorbia esula, commonly known as green spurge or leafy spurge, is a species of spurge native to central and southern Europe, and eastward through most of Asia north of the Himalaya to Korea and eastern Siberia. It can also be found in some parts of Alaska.
Aphthona is a genus of beetle, in the leaf beetle family Chrysomelidae, native to Europe and Asia. More specifically, Aphthona are flea beetles, meaning they have enlarged hind legs for jumping away from potential danger. There are some 300 species known worldwide.
Aphthona flava is a beetle of the genus Aphthona. It is native to Eurasia, and has been introduced into North America as a biocontrol agent for leafy spurge. Adults are brown and difficult to distinguish in the field from A. cyparissiae and A. nigriscutis. A. flava is still the dominant beetle at some Manitoba release sites, but it is relatively scarce in North Dakota and Minnesota. Besides Manitoba, it is widespread in Hungary and Italy.
Euphorbia heterophylla, also known under the common names of Mexican fireplant, painted euphorbia, Japanese poinsettia, paintedleaf, painted spurge and milkweed, is a plant belonging to the Euphorbiaceae or spurge family.
Euphorbia cyparissias, the cypress spurge, is a species of plant in the genus Euphorbia. It is native to Europe and was introduced to North America in the 1860s as an ornamental plant.
Euphorbia myrsinites, the myrtle spurge, blue spurge, or broad-leaved glaucous-spurge, is a succulent species of flowering plant in the spurge family Euphorbiaceae.
The flea beetle is a small, jumping beetle of the leaf beetle family (Chrysomelidae), that makes up the tribe Alticini which is part of the subfamily Galerucinae. Historically the flea beetles were classified as their own subfamily.
Camp Grafton is the main Army National Guard installation in North Dakota. The base, located near Devils Lake, North Dakota, was founded in 1904 as the Rock Island Military Reservation, but later renamed after Gilbert C. Grafton.
Hyles euphorbiae, the spurge hawk-moth, is a European moth of the family Sphingidae. It has been found in Pontresina, Switzerland. This hawk moth is used as an agent of biological pest control against the noxious weed leafy spurge, but usually only in conjunction with other agents. The larvae consume the leaves and bracts of the plant. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.
Leafy spurge may refer to several species of plant in the genus Euphorbia, including:
Aphthona abdominalis is a species of leaf beetle known as the minute spurge flea beetle. It was used as an agent of biological pest control against the noxious weed leafy spurge, but never established a viable population.
Aphthona cyparissiae is a species of leaf beetle known as the brown dot leafy spurge flea beetle. It is used as an agent of biological pest control against the noxious weed leafy spurge.
Aphthona czwalinae is a species of leaf beetle known as the black leafy spurge flea beetle. It is used as an agent of biological pest control against the noxious weed leafy spurge.
A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals. Plants with characteristics that make them hazardous, aesthetically unappealing, difficult to control in managed environments, or otherwise unwanted in farm land, orchards, gardens, lawns, parks, recreational spaces, residential and industrial areas, may all be considered weeds. The concept of weeds is particularly significant in agriculture, where the presence of weeds in fields used to grow crops may cause major losses in yields. Invasive species, plants introduced to an environment where their presence negatively impacts the overall functioning and biodiversity of the ecosystem, may also sometimes be considered weeds.
Aphthona lacertosa is a root-feeding flea beetle of the genus Aphthona. It is one of 5 Aphthona spp. that has been used in Alberta, Canada to control leafy spurge, an invasive plant that reduces pasture quality and degrades natural habitats.
Aphthona nigriscutis is a root-feeding flea beetle of the genus Aphthona. It is one of five Aphthona spp. that has been used in Alberta, Canada to control leafy spurge, an invasive plant that reduces pasture quality and degrades natural habitats. It, along with A. lacertosa, is one of only two biocontrol agents thought to be effective against leafy spurge.
Chamaesphecia hungarica, the Hungarian clearwing moth, is a moth of the family Sesiidae. It is native to the south-eastern Czech Republic and Slovakia, Austria, Hungary, Serbia and Croatia. It was originally approved for introduction into the United States in 1993. It has been released at several leafy spurge-infested sites in Montana and North Dakota.
Oberea erythrocephala, the leafy spurge stem boring beetle or red-headed leafy spurge stem borer is a species of longhorn beetle that is a biological control agent for leafy spurge. It is an effective killer of the pest but only works on certain strains of leafy spurge, namely the subgenus Esula of the genus Euphorbia. Because of this, the beetle is considered as secondary in leafy spurge control to five species of Aphthona flea beetle.
