SAIN Invasive Plant Pests Resource Collection for Euphorbia esula
Common name: Leafy spurge
| Title: Effect of Euphorbia esula on growth and mortality of migratory grasshopper nymphs. |
| Author: Roberts-J-L {a}; Olson-B-E. |
| Source: Journal-of-Agricultural-and-Urban-Entomology. April, 1999; 16 (2): 97-106. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Most herbivores in North America avoid the invasive exotic leafy spurge (Euphorbia esula L.), possibly because E. esula contains high concentrations of terpenoids and condensed tannins. Our objective was to determine if plant parts from undefoliated and previously defoliated E. esula shoots, mixed in different proportions with grass hay, limit growth and increase mortality of nymphs of Melanoplus sanguinipes F. Condensed tannins, a secondary compound, were present in all E. esula plant parts, increased seasonally, and were highest in stems from previously defoliated shoots. For E. esula harvested in July, nymphs presented with leaves from previously defoliated shoots were heavier than those presented with other plant parts, indicating that the high nutritive value of leaves of E. esula in July offset any negative effects associated with secondary compounds. For E. esula harvested in August, increasing proportion of E. esula in the diet reduced nymphal weight, indicating nymphs were sensitive to higher concentrations of secondary compounds when nutritive value of this plant declines in late summer. |
| Title: Quinclorac ester toxicity and metabolism in leafy spurge (Euphorbia esula) soil systems: Effects of foliar vs soil applications. |
| Author: Rusness-Donald-G; Huwe-Janice-K; Lamoureux-Gerald-L. |
| Source: Pesticide-Biochemistry-and-Physiology. Sept. 1, 1998; 61 (2) 115-133. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Quinclorac and 13 synthesized esters were monitored for toxicity in foliar- and soil-treated leafy spurge plants. Foliar treatment at 0.5 mumol/plant with quinclorac resulted with 100% mortality, whereas treatment with esters at 2 mumol/plant showed initial toxicity symptoms, but the plants recovered with time (24 weeks). Foliar toxicity symptoms and mortality increased throughout 24 weeks after soil treatment at 0.4 mumol/plant with the higher MW esters (C5-C16); however, toxicity symptoms decreased and plants recovered after quinclorac or low MW ester treatments. (14C)Quinclorac esters also were monitored to ascertain if toxicity data could be related to ester mobility and/or metabolism. Foliar application showed volatile losses with the low MW esters; complete metabolism of esters occurred inside the treated leaves by 7 days, but little or no quinclorac was observed as a result; and little radiolabel migrated from the leaves. Soil application showed that the esters were metabolized by soil microorganisms through a series of omega- and beta-oxidations and not by simple ester hydrolysis. These intermediate metabolites were identified by MS and NMR analyses. The C6 and C8 esters were metabolized to the quinclorac ester of 4-hydroxybutyric acid as a major intermediate in soil before conversion to quinclorac. The rate of quinclorac release from the various esters was dependent on the number of odd vs even carbons in the ester side chain; the C7, C5, and C8 esters were metabolized to quinclorac at relative rates of 16, 3.2, and 1, respectively. Quinclorac acid was leached readily from soil with water, but the C8 ester was adsorbed. As the higher MW esters released quinclorac in soil over time, concomitantly, the toxicity of leafy spurge after treatment with these esters also increased and was superior to quinclorac after 24 weeks. The slow release of quinclorac from the omega/beta-oxidations of these esters appeared to increase efficacy in soil-treated leafy spurge. |
| Title: AC 263,222 absorption and fate in leafy spurge (Euphorbia esula). |
| Author: Thompson-W-Mack; Nissen-Scott-J {a}; Masters-Robert-A. |
| Source: Weed-Science. Sept.-Oct., 1998; 46 (5) 510-513.` |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Absorption, translocation, and metabolism of AC 263,222 by leafy spurge were studied over 8 d. Based on the amount of herbicide applied and recovered from the leaf surfaces, 40% of applied AC 263,222 was absorbed by leafy spurge 2 d after treatment (DAT), with no further absorption observed by 8 DAT. Eight DAT, 19% of applied (14C)-AC 263,222 had translocated to below-ground plant parts while 4% was exuded from the roots into the sand media. AC 263,222 was not metabolized 2 DAT in the crown, root, and root buds, but 42% was metabolized in the treated leaves. Only 17% of recovered (14C) was AC 263,222 in treated leaves 8 DAT (83% metabolized), while AC 263,222 accounted for 70% of recovered (14C) in the root and root buds. HPLC analysis indicated that the balance of (14C) was associated with a single, polar metabolite. Total recovery of (14C) was 88% at 8 DAT. |
| Title: The biology and integrated management of leafy spurge (Euphorbia esula) on North Dakota rangeland. |
| Author: Lym-Rodney-G. |
| Source: Weed-Technology. April-June, 1998; 12 (2) 367-373. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Leafy spurge, a long-lived perennial, grows in many habitats, from floodplains to grasslands and mountain slopes. The plant emerges in early spring and produces showy, yellow bracts that appear in late May. The true flowers emerge in mid-June. The plant spreads by both seeds and roots and contains a white sticky latex that deters grazing by many animals. Dicamba, 2,4-D, glyphosate, and picloram have commonly been used to control leafy spurge. Picloram plus 2,4-D is frequently used for leafy spurge control in North Dakota. Ten insect species for leafy spurge biocontrol have been released in North Dakota; the most successful have been the flea beetles, Aphthona nigriscutis, A. czwalinae, and A. lacertosa. The leafy spurge gall midge (Spurgia esulae) has been most successful near wooded areas. Herbicides combined with either the leafy spurge flea beetles or gall midge have controlled leafy spurge better than either method used alone. Grazing with sheep or goats is a cost-effective method for controlling leafy spurge top growth in large infestations. Grazing combined with fall-applied picloram plus 2,4-D reduced leafy spurge density more rapidly and maintained control longer than either method used alone. Several grass species are competitive with leafy spurge including 'Rebound' smooth brome, 'Rodan' western wheatgrass, 'Pryor' slender wheatgrass, and 'Manska' pubescent wheatgrass. Cultivating twice each fall after harvest for 3 yr in cropland completely controlled leafy spurge. A successful long-term management program should be designed for specific situations and should include combinations of herbicides, insects, grazing, and/or seeding competitive species. |
| Title: Leafy spurge (Euphorbia esula) control with several grass species. |
| Author: Ferrell-Mark-A {a}; Whitson-Thomas-D; Koch-David-W; Gade-A-E. |
| Source: Weed-Technology. April-June, 1998; 12 (2) 374-380. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Studies were established near Devil's Tower in Crook County, WY, to determine the potential of 11 grass species to compete with leafy spurge as an alternative to repetitive herbicide treatments. Of the 11 species, 'Bozoisky' Russian wildrye and 'Luna' pubescent wheatgrass showed the most promise for successful competition with leafy spurge and were selected for further study. Pubescent wheatgrass limited percent canopy cover of leafy spurge to 10 and 15% or less in tilled and no-till plots, respectively, 7 and 10 yr after seeding. Russian wildrye limited percent canopy cover of leafy spurge to 21% or less in tilled and 7 and 27% in the no-till plots, respectively, 7 or 10 yr after seeding. The control plots not seeded to a forage grass averaged 55% leafy spurge canopy cover. |
| Title: The role of specific plant organs and polar auxin transport in correlative inhibition of leafy spurge (Euphorbia esula) root buds. |
| Author: Horvath-David-P. |
| Source: Canadian-Journal-of-Botany. July, 1998; 76 (7) 1227-1231. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Localization of the source of the signal(s) controlling correlative inhibition of leafy spurge root buds (underground adventitious shoot buds located on the lateral roots) was studied by sequential removal of various plant organs. It was determined that full correlative inhibition of root buds was lost only after excision of all aerial tissue from the plant, or after excision of all aerial tissue except the stem. If mature leaves or growing axillary buds (or both) were left intact, no growth of root buds was observed. The synthetic auxin, alpha-NAA, prevented release of apical dominance and subsequent outgrowth of stem and crown buds when applied to the cut end of the stem or crown. Exogenous application of NAA to either the stem or the crown had little effect on root bud growth. Application of the auxin transport inhibitor NPA around the base of the crown had no effect on root bud quiescence. These data are not consistent with the previous studies (Weed Sci. 35: 155-159 (1987)) that indicate a role for auxin in maintenance of correlative inhibition of root bud growth in leafy spurge. The results of auxin transport inhibitor studies presented here suggest that correlative inhibition of root bud growth does not rely on the classic polar auxin transport system. |
| Title: Taxonomic notes on Euphorbia esula (Euphorbiaceae) with special reference to its occurrence in the east part of the Baltic region. |
| Author: Geltman-Dmitry-V. |
| Source: Annales-Botanici-Fennici. June 30, 1998; 35 (2) 113-117. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The taxonomy, ecology and geography of Euphorbia esula L. and E. virgata Waldst. & Kit. are discussed. It is shown that both taxa have different ecological preferences and distribution patterns. Special attention is paid to the occurrence of E. esula in the east part of the Baltic region, where it shows particularly clear ecological differences from E. virgata. It is proposed to treat both taxa as separate species. |
| Title: Revegetating leafy spurge (Euphorbia esula)-infested rangeland with native tallgrasses. |
| Author: Masters-Robert-A; Nissen-Scott-J. |
| Source: Weed-Technology. April-June, 1998; 12 (2) 381-390. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Degradation of Great Plains rangelands can be linked to past management practices that reduced native species diversity and accelerated establishment and expansion of exotic weeds and less desirable native species. Leafy spurge is an exotic perennial weed that infests more than 1 million ha in the northern Great Plains and reduces rangeland carrying capacity by competing with desirable forages and causing infested areas to be undesirable to cattle and wildlife. Research was conducted to determine the feasibility of using herbicides to suppress leafy spurge and other resident vegetation, which facilitated planting and establishment of native tallgrasses. Four experiments were conducted where 0.28, 0.56, and 0.84 kg ai/ha imazapyr and 0.1 kg ai/ha sulfometuron were applied alone and in combination and 0.84 kg ai/ha glyphosate was applied to leafy spurge-infested range sites in fall 1991 near Ainsworth, NE, and in fall 1991, 1992, and 1993 near Ansley, NE. Research areas were burned about 200 d after herbicide application to reduce plant residue. Monoculture stands of big bluestem and switchgrass were then no-till planted in each experiment and indiangrass was no-till planted in experiments initiated at Ansley in 1992 and 1993. Yields of the planted grasses, leafy spurge, and other vegetation were measured in August at each location starting the year after planting. Imazapyr was an essential component of treatments applied before planting to facilitate establishment of highly productive stands of the tallgrasses. Generally, yields were maximized by fall treatments of 0.28 kg/ha imazapyr + 0.1 kg/ha sulfometuron for big bluestem, 0.84 kg/ha imazapyr for indiangrass, and 0.84 kg/ha imazapyr + 0.1 kg/ha sulfometuron for switchgrass. Yields of the planted grasses were frequently four times greater where these herbicides were applied compared to where glyphosate or no herbicide were applied. Leafy spurge yields were usually reduced in areas where tallgrass yields were greatest. The sequential combination of suppressing vegetation with fall-applied herbicides, burning standing dead plant residue, then no-till planting desirable native tallgrasses in the spring increased productivity of these leafy spurge-infested range sites. |
| Title: Leafy spurge (Euphorbia esula) response to AC 263,222. |
| Author: Masters-Robert-A {a}; Beran-Daniel-D; Rivas-Pantoja-Fernando. |
| Source: Weed-Technology. Oct.-Dec., 1998; 12 (4) 602-609. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Leafy spurge is an exotic perennial weed that infests more than 1 million ha in North America and reduces rangeland carrying capacity. Experiments were initiated on range sites in Nebraska and North Dakota in 1994 and 1995 to determine the response of leafy spurge and other vegetation to AC 263,222. Herbicide treatments evaluated included AC 263,222 at 0 to 280 g ai/ha, picloram at 560 g ai/ha plus 2,4-D at 1,120 g ae/ha, and quinclorac at 1,120 g ai/ha. In Nebraska, a single application of AC 263,222 in the fall at 140 g/ha provided gtoreq 90% leafy spurge control 11 to 12 mo after treatment. At Jamestown, ND, leafy spurge control increased to almost 90% and stem density declined to two shoots/ml 12 mo after the second consecutive fall application of AC 263,222 at 140 g/ha. At Hankinson, ND, leafy spurge control was ltoreq 50% when AC 263,222 was applied in the fall only, but increased to > 80% when AC 263,222 was applied in the fall and again at 70 or 140 g/ha in the spring. There were no differences in herbage biomass of established cool- and warm-season grasses where AC 263,222 at 140 g/ha, picloram plus 2,4-D, quinclorac, or no herbicide was applied in the fall. In contrast, application of AC 263,222 in the fall and again in the spring usually reduced cool-season grass biomass. |
| Title: Leafy spurge (Euphorbia esula) control with quinclorac. |
| Author: Kuehl-Brian-D {a}; Lym-Rodney-G. |
| Source: Weed-Technology. 1997; 11 (2) 265-269. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Quinclorac is a systemic herbicide registered to control annual grass and broadleaf weeds in rice. Field research was conducted to determine the most effective quinclorac treatment for leafy spurge control. Leafy spurge control 12 mo after treatment (MAT) averaged 38 and 77% when quinclorac was applied at 0.56 and 1.7 kg ae/ha, respectively. Quinclorac applied with the crop-oil-based adjuvant Scoil provided similar leafy spurge control compared to quinclorac applied alone. Quinclorac plus Scoil applied with picloram provided better leafy spurge control than quinclorac plus Scoil alone. The optimum date for fall treatment with quinclorac is broad. Quinclorac at 1.1 kg/ha plus Scoil at 2.3 L/ha applied on September 1, September 15, October 1, and October 15 provided similar leafy spurge control and averaged 56% 12 MAT. |
| Title: Distribution of biological control agents of leafy spurge (Euphorbia esula L.) in the United States: 1988-1996. |
| Author: Hansen-Richard-W {a}; Richard-Robert-D {a}; Parker-Paul-E; Wendel-Lloyd-E. |
| Source: Biological-Control. 1997; 10 (2) 129-142. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Leafy spurge, Euphorbia esula (Euphorbiaceae), is a perennial plant native to Eurasia that has become a widespread weed in North America. Since 1988, the United States Department of Agriculture, Plant Protection and Quarantine, Animal and Plant Health Inspection Service (USDA-APHIS-PPQ) has coordinated a classical biological control implementation program against leafy spurge in the United States. Through this program, nine Eurasian insect species have been imported and released in the United States, including six species of flea beetles, Aphthona spp. (Coleoptera: Chrysomelidae), a root-boring moth, Chamaesphecia hungarica (Lepidoptera: Sesiidae), a root-boring beetle, Oberea erythrocephala (Coleoptera: Cerambycidae), and a gall midge, Spurgia esulae (Diptera: Cecidomyiidae). These species have been released in 188 counties in 19 states. Established populations of at least one agent are present in 148 counties in 18 states, while populations of at least one agent in 62 counties in 16 states are large enough to permit collection and distribution to other leafy spurge-infested areas. Biological control agents have been released throughout areas of the United States infested by leafy spurge, and the initial phase of the USDA-APHIS-PPQ implementation program is nearly complete. |
| Title: Image analysis of leafy spurge (Euphorbia esula) cover. |
| Author: Birdsall-Jennifer-L {a}; Quimby-Paul-C-Jr; Rees-Norman-E; Svejcar-Tony-J; Sowell-Bok-F. |
| Source: Weed-Technology. Oct.-Dec., 1997; 11 (4) 798-803. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: We examined whether image analysis could separate leafy spurge from other plant species and objects by comparing image analysis to the ocular method of estimating cover. Image analysis was acceptably precise at low and medium cover levels. Image analysis was as repeatable as the ocular method at all sites and cover levels and acceptably reliable at low and medium cover levels but estimated cover lower by 12 to 22% than the ocular method at high cover levels. The average error levels of image analysis and the ocular method did not differ. Estimating leafy spurge cover with a 10% error required only 20 quadrats when image analysis was used, while twice as many quadrats were needed when cover was measured ocularly. Image analysis was recommended as a measurement tool because quantification was efficient, the equipment is inexpensive, and the color prints provide a permanent photo record of the study. |
| Title: Effects of simulated defoliation on leafy spurge (Euphorbia esula)-infested rangeland. |
| Author: Kirby-Donald-R-Kirby {a}; Hanson-Thomas-P; Krabenhoft-Kelly-D; Kirby-Matt-M. |
| Source: Weed-Technology. 1997; 11 (3) 586-590. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: The effect of annual defoliation on leafy spurge-infested rangeland was investigated over a 5-yr period. Artificial defoliation was conducted once or twice annually at various phenological growth stages of leafy spurge to simulate grazing by herded Angora goats. Single defoliation treatments did not reduce total leafy spurge stem densities. Defoliation twice in a growing season for 4 consecutive yr reduced total leafy spurge stem densities by 55% over nondefoliated controls. Grass foliar cover and yield increased in all defoliation treatments. Despite the increased grass yield on single defoliation treatments, cattle use would likely be limited in these treatments due to the high density of leafy spurge stems. Stem densities of leafy spurge in twice-defoliated treatments should not deter cattle from grazing these sites, thereby increasing the available forage supply. The data suggest that repeated grazing of leafy spurge-infested rangeland within a growing season would be required to reduce stem densities adequately and increase cattle use and production from these sites. |
| Title: Diets of Angora goats grazing leafy spurge (Euphorbia esula)-infested rangeland. |
| Author: Kirby-Donald-R {a}; Hanson-Thomas-P; Sieg-Carolyn-Hull. |
| Source: Weed-Technology. Oct.-Dec., 1997; 11 (4) 734-738. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Angora goats have been suggested as biological control agents for leafy spurge, especially in environmentally sensitive or limited access areas. Dietary preferences and dietary nutritive content of herded Angora goats were evaluated over a two-year period in North Dakota. Relative preferences of forages were evaluated by comparing botanical composition of diets as determined by microhistological analysis of fecal samples to forage availability in the field. Leafy spurge and shrubs comprised the largest percentage of goat diets throughout each grazing season. Goats preferred leafy spurge and shrubs at all times and avoided most cool-season grass species. The nutritional requirements of Angora goats nursing kids were met throughout the grazing season. Use of Angora goats is another tool available to land managers to manage leafy spurge infestations in the Northern Plains. |
| Title: Attack behavior and host utilization of Aphthona chinchihi (Col.: Chrysomelidae), a potential biological control agent of Euphorbia esula (Euphorbiaceae, leafy spurge) in North America. |
| Author: Fornasari-L. |
| Source: Entomophaga-. 1997; 42 (4) 605-617. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Aphthona chinchihi Chen was collected in China feeding on leafy spurge (Euphorbia esula L.). Studies were conducted on its host specificity in the laboratory, using field collected adults and their progeny. Aphthona chinchihi can effectively complement the impact of the other natural enemies of leafy spurge established from Europe in the U.S.A. and Canada. The adults feed on leaves and shoots and the larvae, which cause the main damage to the plant, feed on the hypogeous portion of the plant, seriously stressing the plant and preventing its vegetative spread. The host range of A. chinchihi was studied with tests on adult feeding and oviposition, larval survival and host suitability, using 40 plant species or varieties distributed in 12 families. The experiments demonstrated that it has a high level of specificity. This flea beetle completed its life cycle only on leafy spurge. Also, because of its ecological valence, A. chinchihi has a very good potential as a biocontrol agent in North America. |
| Title: Competitive grasses for leafy spurge (Euphorbia esula) reduction. |
| Author: Lym-Rodney-G {a}; Tober-Dwight-A. |
| Source: Weed-Technology. Oct.-Dec., 1997; 11 (4) 787-792. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Twelve grass genotypes were evaluated for competitiveness with leafy spurge and herbage yield in two sites in North Dakota. 'Rebound' smooth brome, 'Rodan' western wheatgrass, 'Bozoisky' Russian wildrye, and 'Arthur' Dahurian wildrye reduced leafy spurge stem density an average of 63% after 3 yr in a silty clay soil at Fargo. 'Reliant' intermediate wheatgrass reduced leafy spurge stem density every year for 3 yr, including an 85% reduction the second year after planting, and consistently produced high herbage yields. Rebound smooth brome and Reliant intermediate wheatgrass averaged 72% leafy spurge reduction 3 yr after seeding in a loamy sand soil at Jamestown. Reliant intermediate wheatgrass and 'Manska' pubescent wheatgrass provided the most consistent herbage production, which averaged about 2,000 kg/ha annually for 3 yr. |
| Title: Genetic variation in North American leafy spurge (Euphorbia esula) determined by DNA markers. |
| Author: Rowe-Martha-L {a}; Lee-Donald-J; Nissen-Scott-J; Bowditch-Brunella-M; Masters-Robert-A. |
| Source: Weed-Science. 1997; 45 (3) 446-454. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Levels of inter- and intrapopulation genetic variation were determined in five North American populations of leafy spurge using chloroplast DNA (cpDNA) RFLPs and RAPD markers. Thirteen plastome types were identified among 123 individuals collected from five geographically separated populations. Number of plastomes within a population ranged from one to seven, with four of the populations having a predominate type plus one or more rarer types. Some plastome types were shared by populations, but plastome distribution among populations was nonrandom. RAPD markers indicated greatest relatedness among individuals within a population. Relatedness among populations as established through RAPDs was greater for geographically closer populations; this relationship was not observed for cpDNA markers. Differences in the range of movement for pollen and seed may account for differences between results of the cpDNA and RAPD analyses. The high degree of genetic variability among North American leafy spurge suggests possible multiple introductions or a high degree of variability within leafy spurge populations in its native range. |
| Title: Identity, pathogenicity, and comparative virulence of Fusarium spp. related to stand declines of leafy spurge (Euphorbia esula) in the Northern Plains. |
| Author: Caesar-A-J. |
| Source: Plant-Disease. 1996; 80 (12) 1395-1398. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Strains of Fusarium spp. causing root disease and crown rot on leafy spurge in natural epidemics and in association with stand declines were identified as F. oxysporum, F. solani, and F. proliferatum. These species predominated among Fusarium spp. isolated from stunted and diseased feeder roots and crowns. There were significant differences in virulence for strains among and within each species. Two strains of F. oxysporum belonged to the same vegetative compatibility group. Ten of 11 strains of Fusarium originated from noncropped or wild areas. These results indicate that Fusarium spp. capable of causing disease on leafy spurge vary as to species, virulence, and compatibility group and are found in a number of sites where this troublesome perennial weed occurs. |
| Title: (Herrich-Shaeffer 1851).(Lep., Tortricidae, Olethreutinae) a possible agent for biological control of Euphorbia esula L. in North America. |
| Author: Sobhian-RAcroclita subsequana. |
| Source: Journal-of-Applied-Entomology. 1996; 120 (6) 383-384. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: NA |
| Title: Description of European Chamaesphecia spp. (Lepidoptera: Sesiidae) feeding on Euphorbia (Euphorbiaceae), and their potential for biological control of leafy spurge (Euphorbia esula) in North America. |
| Author: Tosevski-I; Gassmann-A {a}; Schroeder-D. |
| Source: Bulletin-of-Entomological-Research. 1996; 86 (6) 703-714. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The description of the ten Chamaesphecia species associated with Euphorbia in eastern and south-eastern Europe is based on external adult morphology, male and female genitalia, and the structure of the egg chorion. These species can be divided into two groups according to the shape of the setae of the dorso-basal part of the valvae in the male genitalia. Most Chamaesphecia species are associated with one species of host-plant and all are closely tied to one habitat type. The host-plant and the structure of the egg chorion are fundamental characteristics for the determination of a few species, and very helpful for the others. All species bore into the main root of their host-plant and overwinter as larvae. With the exception of two species which have an annual or biennial life cycle, all species are univoltine. The larvae of three of the eight Chamaesphecia spp. investigated feed and develop in the roots of North American leafy spurge, Euphorbia esula sensu lato. Of these, the best candidate for the biological control of leafy spurge is C. crassicornis, because the larvae have a similar survival rate on the target weed and the European host-plant, E. virgata. |
| Title: Biology, ecology, and host specificity of European Aphthona spp. (Coleoptera, Chrysomelidae) used as biocontrol agents for leafy spurge, Euphorbia esula (Euphorbiaceae), in North America. |
| Author: Gassmann-A {a}; Schroeder-D {a}; Maw-E; Sommer-G. |
| Source: Biological-Control. 1996; 6 (1) 105-113. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Leafy spurge (Euphorbia esula) is an herbaceous perennial of European origin that was accidentally introduced into North America where it has become a serious weed in pastures and rangelands. Five species of root-feeding chrysomelid beetles in the genus Aphthona have been released in North America for the biological control of leafy spurge. They originate from central and eastern Europe and occur in different habitats. The brown species, Aphthona cyparissiae, Aphthona flava, and Aphthona nigriscutis, occur predominantly in open dry habitats, and the black species, Aphthona czwalinai and Aphthona lacertosa, prefer moister habitats. All five species are univoltine and overwinter as larvae. The host range of these five Aphthona species is restricted to species in the subgenus Esula. |
| Title: Leafy spurge (Euphorbia esula) genotype affects gall midge (Spurgia esulae) establishment. |
| Author: Lym-Rodney-G {a}; Nissen-Scott-J; Rowe-Martha-L; Lee-Donald-J; Masters-Robert-A. |
| Source: Weed-Science. 1996; 44 (3) 629-633. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Greenhouse cage studies were conducted to determine the influence of shoot morphology and genetic variation on establishment of Spurgia esulae gall midge on seven leafy spurge genotypes. The genotypes were collected from South Dakota, North Dakota, Nebraska, Montana, Wyoming, Manitoba, and Austria. Genotypes from South Dakota and Nebraska were most susceptible to gall formation and had the highest larvae survival, while the genotypes from Montana and Manitoba were most resistant. Morphological characteristics of the leafy spurge stem tips, such as stem diameter, leaf length, width, and area did not correlate with gall formation or larvae survival. Chloroplast DNA restriction fragment length polymorphism analysis of the genotypes identified six chloroplast types among the seven leafy spurge genotypes. The two genotypes most resistant to galling by S. esulae, Manitoba and Montana. had the same chloroplast genotype, but also were closely related to the two most susceptible genotypes. Because eggs were laid on all genotypes, it appears that adult females were not preferentially selecting appropriate host genotypes, but that egg and larvae survival was strongly influenced by genotype. |
| Title: Life history and host specificity of Aphthona venustula Kutsch. (Col., Chrysomelidae), a candidate for the biological control of leafy spurge (Euphorbia esula L.) in North America. |
| Author: Gassmann-A. |
| Source: Journal-of-Applied-Entomology. 1996; 120 (7) 405-411. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Studies on the life history and host specificity of the root-feeding chrysomelid Aphthona venustula were made to determine the suitability of this insect as a classical biological control agent for leafy spurge (Euphorbia esula) in North America. The adults of A. venustula emerge in summer, and are in reproductive diapause until the following spring when the main adult feeding and oviposition activity occurs. A. venustula prefers mesic shaded and transitional areas but can survive on formerly forested land. The experimental adult feeding range of the beetle is restricted to species in genus Euphorbia, while the larval feeding range is restricted to species in subgenus Esula. Within its habitat in Europe, the beetle discriminates between species in subgenus Esula. |
| Title: Surveillance, for the years 1994 and 1995, of flea-beetles (Coleoptera: Chrysomelidae: Aphthona spp.) released at Marshall Bay (Ontario) against the euphorbia (Euphorbia esula L.). |
| Author: Lesage-Laurent. |
| Source: Proceedings-of-the-Entomological-Society-of-Ontario. 1996; 127 (0) 125-126. |
| Source Type: Paper |
| Publication Date: 1996 |
| Abstract: The introduced population of Aphthona nigriscutis Foudras increased significantly in 1994 and 1995, but not enough to damage the host-plant. The unexpected capture of Aphthona flava Guillebeau, a yellow species superficially similar to the previous one, demonstrates that specimens had evidently been misidentified in the original shipment of flea-beetles. |
| Title: Seasonal expression patterns and characterization of a Euphorbia esula root storage protein. |
| Author: Luster-Douglas-G {a}; Farrell-Harold-M-Jr. |
| Source: Plant-Physiology-and-Biochemistry-Paris. 1996; 34 (1) 111-118. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: High-abundance, water-soluble root proteins are hypothesized to be potential storage forms of reduced N assimilate in perennial weeds. Rabbit antiserum raised against an electrophoretically purified 29 kDa root protein of leafy spurge (Euphorbia esula L.) was used to follow seasonal protein accumulation patterns as well as responses to photoperiod and decapitation. Accumulation of the protein in roots of field-grown plants began during late spring months, with maximal accumulation observed during fall and winter months. Protein accumulation patterns over an 8-week period were similar in root extracts from controlled-environment long- and short-day-grown plants at 30 degree C. Decapitation of the shoot resulted in an immediate decline of the 29 kDa protein in the roots, followed by a gradual increase as shoots expanded from root buds over a 4-week period. These accumulation patterns suggest that dormant leafy spurge root buds may exploit the degradation of stored N root reserves in the form of soluble storage proteins for amino acids to fuel expansion and growth when the buds are released from apical dominance and the root undergoes a transition from sink to source. Processes controlling the accumulation or remobilization of such perennial root storage proteins thus provide potential targets for chemical or biological weed control agents. |
| Title: Adjuvant effects on imazethapyr, 2,4-D and picloram absorption by leafy spurge (Euphorbia esula). |
| Author: Thompson-W-Mack {a}; Nissen-Scott-J; Masters-Robert-A. |
| Source: Weed-Science. 1996; 44 (3) 469-475. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Laboratory experiments were conducted to identify adjuvants that improve absorption of imazethapyr, 2,4-D amine, and picloram by leafy spurge. Adjuvants (0.25% v/v) included crop oil concentrate (COC), methylated seed oil (MSO), nonionic surfactant (NIS), organosilicones (Silwet L-77 , Sylgard 309, Silwet 408), 3:1 mixtures of acetylinic diol ethoxylates (ADE40, ADE65, ADE85) with Silwet L-77, ammonium sulfate (2.5 kg ha-'), and 28% urea ammonium nitrate (UAN, 2.5% v/v). Adjuvants were combined with 'IC-herbicide and commercially formulated herbicide product. Leaves were harvested 2 DAT, rinsed with 10% aqueous methanol to remove surface deposits of herbicide, and dipped in 9:1 hexane:acetone to solubilize cuticular waxes. Imazethapyr absorption increased by 38 to 68% when UAN was combined with COC, NIS, or MSO. Total absorption of imazethapyr plus COC, MSO, or NIS exceeded 86% 2 DAT when UAN was added. Urea ammonium nitrate reduced the amount of imazethapyr associated with the cuticular wax by 2.0%. Imazethapyr absorption was similar on both the abaxial and adaxial leaf surface when UAN was not added, however, 12% more imazethapyr was absorbed from the abaxial leaf surface than from the adaxial leaf surface when UAN was combined with Sylgard 309. Uptake of 2,4-D ranged from 54 to 78% and was greatest with Silwet 408 and 3:1 mixture of ADE40:Silwet L-77. Picloram absorption ranged from 3 to 19%. Buffering picloram treatment solutions to pH 7 and including 2.5 kg ha-1 ammonium sulfate increased picloram absorption to 37%. |
| Title: Interaction of rhizobacteria with leafy spurge (Euphorbia esula L.) callus tissue cells. |
| Author: Souissi-T; Kremer-R-J {a}; White-J-A. |
| Source: Plant-Cell-Tissue-and-Organ-Culture. 1996-1997; 47 (3) 279-287. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The interaction of two rhizobacterial isolates, Pseudomonas fluorescens isolate LS102 and Flavobacterium balustinum isolate LS105, with leafy spurge cells at the cellular level was studied using scanning and electron microscopy. Leafy spurge callus tissue inoculated with either isolate showed considerable changes compared to non-inoculated tissue. The attachment of rhizobacteria to cell surfaces was associated with the elaboration of fibrillar material which may anchor bacteria to surfaces and contribute to mediation of the phytotoxic effect caused by rhizobacteria. At the ultracellular level, inoculated callus tissue showed numerous cell alterations including vesiculation and convolution of the plasmalemma, cell wall degradation and disorganization of the cytoplasm, similar to those detected in the whole plant. It is concluded that callus tissue may provide an excellent working model to investigate the mode and/or mechanism of action of potential biocontrol agents on their host plants. |
| Title: Seasonal changes in the starch content, and associated anabolic and catabolic enzymes, in the roots of the perennial weed Euphorbia esula. |
| Author: Macisaac-Susan-A; Bewley-J-Derek. |
| Source: Plant-Physiology-and-Biochemistry-Montrouge. 1995; 33 (2) 163-171. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Starch is the principal carbohydrate reserve in the persistent roots of the perennial weed leafy spurge (Euphorbia esula). It increases during the autumn and early winter months, and is stored in the cortical cells and rays of the secondary xylem. There is a poor temporal correlation between the activities of several of the major enzymes associated with starch synthesis, and the deposition of the reserve itself. Better correlations exist between the mobilization of starch and the appearance of amylases. Two forms of alpha-amylase with different molecular masses, and four different pI forms are present in the roots. The peaks of starch phosphorylase activity are similar to those of the amylases, although a role for this enzyme in starch synthesis is possible. |
| Title: The search for effective biological control agents in Europe: History and lessons from leafy spurge (Euphorbia esula L.) and cypress spurge (Euphorbia cyparissias L.). |
| Author: Gassmann-A; Schroeder-D. |
| Source: Biological-Control. 1995; 5 (3) 466-477. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: During field surveys made in Europe nearly 40 specialized insect species were found and considered as potential biological control agents of leafy spurge and cypress spurge (Euphorbia esula and Euphorbia cyparissias). More insect species were found on the most common and the geographically most widespread spurge species and on those occurring in a wide range of habitat types. The insect families most frequently associated with perennial spurges in Europe are the chrysomelids, sesiids, cecidomyids, and anthomyiids. Although the areas surveyed include only the most western parts of the leafy spurge and cypress spurge distribution in the Palearctic, all food niches and habitats of the target weeds were found to be occupied by herbivorous insects. The history of the search for biological control agents of leafy and cypress spurges in Europe is briefly reviewed. The selection of candidate agents during the past 30 years is discussed, and the 22 insect species which have been screened so far are briefly considered. It is concluded that suitable agents were found outside optimal survey areas with regard to ecoclimatic and host-plant matching. |
| Title: Temperature effects on the embryonic development of Aphthona abdominalis (Coleoptera: Chrysomelidae), a natural enemy of Euphorbia esula (Euphorbiales: Euphorbiaceae). |
| Author: Fornasari-Luca. |
| Source: Environmental-Entomology. 1995; 24 (3) 720-723. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: The flea beetle Aphthona abdominalis Duftschmid was selected as a candidate for biological control of Euphorbia esula L. (leafy spurge) in North America, where this introduced plant is a serious weed. The insect was collected and studied in Italy, where it occurs naturally. As part of the study of its life history, the effect of temperature on embryonic development was investigated at constant temperatures of 12, 15, 20, 25, 30, 35, 38, and 41 degree C, and variable temperatures were used as well. Survival and developmental rates were obtained. The median values used to calculate the time required for embryonic development through the thermal summation, a linear regression, and the logistic equation are discussed. The experimental data gave a developmental zero between 12 and 13 degree C. Embryos completed their development at constant temperatures from 15 to 38 degree C. Development required from 32.6 d at 15 degree C to only 4.5 d at 35 degree C constant temperatures. A. abdominalis was cleared and introduced into the United States during 1993. |
| Title: Host specificity of Aphthona abdominalis Duftschmid (Coleoptera: Chrysomelidae), a biological control agent for Euphorbia esula L. (Leafy spurge, Euphorbiaceae) in North America. |
| Author: Fornasari-L {a}; Pecora-P. |
| Source: Biological-Control. 1995; 5 (3) 353-360. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Studies were conducted to determine the host specificity of Aphthona abdominalis both in the field and in the laboratory, using field-collected adults and their overwintering progeny. A. abdominalis has four or more generations per year in Italy and occupies a well-defined ecological niche on Euphorbia esula L., leafy spurge. Therefore, it can effectively complement the impact of damage caused by other natural enemies of leafy spurge; the other species of Aphthona previously released are univoltine. The main damage by A. abdominalis is caused by the larvae feeding on the roots and the underground portions of shoots throughout the generations of this multivoltine flea beetle. Experiments were conducted on its host specificity using 56 plant species in 21 families, in addition to the control species. Tests with larvae and adults, conducted in the laboratory and in the field, under no-choice and free-choice conditions, demonstrated that this flea beetle has a high level of specificity. In the field, under freechoice conditions, A. abdominalis attacked and developed only on leafy spurge. This flea beetle has a good potential for being effective in humid habitats, where other flea beetles previously released did not perform well. |
| Title: Quinclorac absorption, translocation, metabolism, and toxicity in leafy spurge (Euphorbia esula). |
| Author: Lamoureux-Gerald-L; Rusness-Donald-G. |
| Source: Pesticide-Biochemistry-and-Physiology. 1995; 53 (3) 210-226. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Quinclorac is a herbicide registered in the United States for use in rice. In this study, the uptake, metabolism, translocation, and toxicity of quinclorac were evaluated for the suitability of this herbicide for use in the control of leafy spurge. (14C)Quinclorac in the presence of a surfactant was readily absorbed through the leaves of leafy spurge. After foliar application, ca. 20% of the quinclorac became sequestered in the treated leaves. The remainder of the quinclorac was translocated basipetally and acropetally. The young leaves and apex were the strongest sinks for quinclorac. Although quinclorac was translocated to the roots, it was effluxed rapidly from the roots into the soil. Quinclorac was also taken up by the roots and translocated acropetally. It was metabolized to a C-1 glucose ester that was converted subsequently to a pentosylglucose ester (major product) or a malonyglucose ester (minor product). Quinclorac was metabolized at a rate of 1 nmol/g tissue/hr in the young leaves. Quinclorac was toxic to leafy spurge when applied to the leaves (LD-50 2.0 kg/ha), the soil (LD-50 1.7 kg/ha). or to both the leaves and the soil (LD-50 1.0 kg/ha). The activity of soil-applied quinclorac was increased 24-fold when the shoots were cut off at the soil level prior to treatment (LD-50) 0.07 kg/ha). Symptoms were typical of an auxenic herbicide. |
| Title: Absorption and fate of imazapyr in leafy spurge (Euphorbia esula). |
| Author: Nissen-Scott-J {a}; Masters-Robert-A; Thompson-W-Mack; Stougaard-Robert-N. |
| Source: Pesticide-Science. 1995; 45 (4) 325-329. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Imazapyr absorption, translocation, root release and metabolism were examined in leafy spurge (Euphorbia esula L.). Leafy spurge plants were propagated from root cuttings and (14C)imazapyr was applied to growth-chamber-grown plants in a water + 28% urea ammonium nitrate + nonionic surfactant solution (98.75 + 1 + 0.25 by volume). Plants were harvested two and eight days after herbicide treatment (DAT) and divided into: treated leaf, stem and leaves above treated leaf, stem and leaves below the treated leaf, crown, root, dormant and elongated adventitious shoot buds. Imazapyr absorption increased from 62.5% 2 DAT to 80.0% 8 DAT. Herbicide translocation out of the treated leaf and accumulation in roots and adventitious shoot buds was apparent 2 DAT. By the end of the eight-day translocation period only 14% of applied 14C remained in the treated leaf, while 17% had translocated into the root system. Elongated and dormant adventitious shoot buds accumulated 3.2- and 1.8-fold more 14C, respectively, 8 DAT than did root tissue based on Bq g-1 dry weight. Root release of 14C was evident 2 DAT, and by 8 DAT 19.4% of the 14C reaching the root system was released into the rooting medium. There was no metabolism of imazapyr in crown, root or adventitious shoot buds 2 DAT; however, imazapyr metabolism was evident in the treated leaf 2 and 8 DAT. Imazapyr phytotoxicity to leafy spurge appears to result from high imazapyr absorption, translocation to underground meristematic areas (roots and adventitious shoot buds), and a slow rate of metabolism. |
| Title: Use of remote sensing for detecting and mapping leafy spurge (Euphorbia esula). |
| Author: Everitt-James-H {a}; Anderson-Gerald-L; Escobar-David-E; Davis-Michael-R; Spencer-Neal-R; Andrascik-Roger-J. |
| Source: Weed-Technology. 1995; 9 (3) 599-609. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Leafy spurge is a troublesome, exotic weed in the northern Great Plains of the United States. Leafy spurge produces showy yellow bracts during June that give this weed a conspicuous appearance. A study was conducted to determine the feasibility of using remote sensing techniques to detect leafy spurge in this phenological stage. Study sites were located in North Dakota and Montana. Plant canopy reflectance measurements showed that leafy spurge had higher visible (0.63- to 0.69-mu-m) reflectance than several associated plant species. The conspicuous yellow bracts of leafy spurge gave it distinct yellow-green and pink images on conventional color and color-infrared aerial photographs, respectively. Leafy spurge also could be distinguished on conventional color video imagery where it had a golden yellow image response. Quantitative data obtained from digitized video images showed that leafy spurge had statistically different digital values from those of associated vegetation and soil. Computer analyses of video images showed that light reflected from leafy spurge populations could be quantified from associated vegetation. This technique permits area estimates of leafy spurge populations. Large format conventional color photographs of Theodore Roosevelt National Park near Medora, ND were digitized and integrated with a geographic information system to produce a map of leafy spurge populations within the park that can be useful to monitor the spread or decline of leafy spurge. Nomenclature: Leafy spurge, Euphorbia esula L., -3 EPHES. |
| Title: Moisture requirements and host specificity of Rhizoctonia solani from leafy spurge (Euphorbia esula) in Nebraska. |
| Author: Yuen-Gary-Y {a}; Masters-Robert-A. |
| Source: Weed-Technology. 1995; 9 (1) 44-48. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: R230, an isolate of Rhizoctonia solani anastomosis group 5 from leafy spurge, caused root and crown rots on leafy spurge when inoculated via soil in greenhouse experiments. The fungus grew through soil over a wide range of matric potentials (-0.01 to -1 MPa). When applied to leafy spurge foliage, the fungus blighted young adventitious shoots, but not mature stems. Foliar infection required high relative humidity. Mycelial growth on plant surfaces stopped at below 92% relative humidity. Pathogenicity of R230 was not limited to leafy spurge. The fungus caused stem and foliar lesions on all crops tested (alfalfa, smooth bromegrass, corn, Kentucky bluegrass, soybean, tall fescue, and wheat) when plants were kept under high humidity. It reduced seedling emergence and survival in soybean, Kentucky bluegrass, and tall fescue. R230 also caused a foliar blight on spotted spurge. The potential for R230 to damage crops will limit application of the fungus to noncultivated areas and to sites where it is endemic. |
| Title: Effects of putrescine and inhibitors of putrescine biosynthesis on organogenesis in Euphorbia esula L. |
| Author: Davis-David-G; Olson-Prudence-A. |
| Source: In-Vitro-Cellular-and-Developmental-Biology-Plant. 1994; 30P (2) 124-130. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Exogenous putrescine ( ltoreq 5 mM) had little effect on root or shoot formation in aseptically isolated hypocotyl segments of leafy spurge (Euphorbia esula L.) grown on full-strength B5 medium. Unexpectedly, putrescine inhibited root and shoot formation in hypocotyl segments grown on B5 medium diluted 10-fold. In the full-strength medium, root and shoot formation were inhibited by 0.5 mM concentrations of DL-alpha-difluoromethylornithine (DFMO) and DL-alpha-difluoromethylarginine (DFMA). DFMO and DFMA are inhibitors of the ornithine decarboxylase and arginine decarboxylase pathways, respectively, of putrescine biosynthesis in plants. Exogenous putrescine (0.5 to 5 mM) did not reverse either the DFMO- or DFMA-induced inhibition of shoot formation. However, the DFMA-induced inhibition of root formation was partially reversed by exogenous putrescine. The auxin, indole-3-acetic acid (IAA), reduced the inhibitory effects of DFMO+DFMA (applied together) on both roots and shoots. In the first few days of culture, the endogenous levels of putrescine and spermidine, but not of spermine, increased in the presence of IAA. The levels of putrescine and spermidine in the tissues did not correlate well with either root or shoot production in the later stages of organ formation; especially in tissues treated with IAA. These results show that there were no obvious correlations between polyamine levels and organogenesis in leafy spurge hypocotyl segments, although residual putrescine or spermidine or both in the tissues at the time of excision may be indirectly involved in the early stages of root formation. |
| Title: Comparative virulence of strains of Rhizoctonia spp. on leafy spurge (Euphorbia esula) and disease reactions of cultivated plants in the greenhouse. |
| Author: Caeser-A-J. |
| Source: Plant-Disease. 1994; 78 (2) 183-186. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Six multinucleate and two binucleate strains of Rhizoctonia spp. pathogenic to the weed leafy spurge (Euphorbia esula) were compared in aggressiveness. Pathogenicity was tested by inoculating stems of leafy spurge or planting roots or seeds in soil infested with Rhizoctonia strains (8 cfu/g). Two multinucleate strains were significantly more virulent on roots of leafy spurge than the other strains. Eleven cultivated plant species were found to be susceptible to at least one of the eight Rhizoctonia strains, having mean disease ratings significantly different (P = 0.05) from those of control plants. Two or more strains caused significantly different mean disease ratings in eight of these host species, indicating that there was variation among strains. Four strains had equally broad host ranges of six plant species, but their respective host ranges were not identical. The two binucleate strains, which ranked lowest in overall aggressiveness to leafy spurge, also had relatively narrow host ranges of one and three species. The results indicate variation in aggressiveness to leafy spurge and in host range among strains of Rhizoctonia spp., from which optimum biocontrol strains may be selected for appropriate use. |
| Title: Imazethapyr absorption and fate in leafy spurge (Euphorbia esula). |
| Author: Nissen-Scott-J {a}; Masters-Robert-A {a}; Stougaard-Robert-N. |
| Source: Weed-Science. 1994; 42 (2) 158-162. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Absorption, translocation, root release, and metabolism of imazethapyr by leafy spurge were determined under growth chamber conditions. 14C-imazethapyr was applied to vegetatively propagated leafy spurge plants in a 1 % solution of 28 % urea ammonium nitrate containing 0.25 % by vol nonionic surfactant. Plants were harvested 2 and 8 d after herbicide application. Imazethapyr absorption increased from 9 % at 2 d to 20 % at 8 d. Acropetal and basipetal translocation out of the treated leaf was observed, with 3.4 to 4.2 % of the applied radioactivity accumulating in the root by the end of the 8-d time course. Eight days after herbicide application, radioactivity in dormant and elongated adventitious shoot buds was twofold higher than in root tissue (compared on a dry wt basis). Two days after herbicide application, 93% of the radioactivity remained as intact imazethapyr in the treated leaf, crown, root, and shoot buds. Eight days after application, crown, roots, and adventitious shoot buds had metabolized an average of 61, 36, and 47 % of the imazethapyr, respectively, while only 14% was metabolized in the treated leaf. The primary metabolite cochromatographed with 5-hydroxyethyl-imazethapyr standard. Nomenclature: Imazethapyr, 2-(4,5-dihydro-4ethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl)-5-ethyl-3pyridinecarboxylic acid; leafy spurge, Euphorbia esula L. -3 EPHES. |
| Title: Leafy spurge (Euphorbia esula) control with imidazolinone and sulfonylurea herbicides. |
| Author: Stougaard-Robert-N {a}; Masters-Robert-A; Nissen-Scott-J. |
| Source: Weed-Technology. 1994; 8 (3) 494-498. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Experiments were conducted to determine the efficacy of imidazolinone and sulfonylurea herbicides applied alone or in combination to control leafy spurge. Imazapyr (840 g ai/ha), imazethapyr (140 g/ha), sulfometuron (100 g/ha), and chlorsulfuron (20 g/ha) were applied in the fall on rangeland sites near Ainsworth and Columbus, NE. Imidazolinone and sulfonylurea herbicide combinations did not improve leafy spurge control nor affect forage grass yields when compared with herbicides applied alone. Imazapyr and sulfometuron were the most efficacious, providing greater than 80% leafy spurge control 9 mo after treatment (MAT). Imazethapyr provided 80% control of leafy spurge 9 MAT when applied to a coarse textured, low organic matter soil. In contrast, leafy spurge control was only 15% when imazethapyr was applied to a fine textured soil. Chlorsulfuron did not control leafy spurge, regardless of site characteristics. Imazapyr reduced perennial grass yields by more than 60%. Nomenclature: Chlorsulfuron, 2-chloro-N-(((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino)carbonyl)benzenesulfonamide; imazapyr, +--2-(4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl)-3-pyridinecarboxylic acid; imazethapyr, 2-(4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl)-5-ethyl-3-pyridinecarboxlic acid; sulfometuron, 2-((((4,6-dimethyl-2-pyrimidinyl)amino)carbonyl)amino)sulfonyl)benzoic acid; leafy spurge, Euphorbia esula L. -3 EPHES. |
| Title: Leafy Spurge (Euphorbia esula) Control, Forage Production, and Economic Return with Fall-Applied Herbicides. |
| Author: Lym-Rodney-G {a}; Messersmith-Calvin-G. |
| Source: Weed-Technology. 1994; 8 (4) 824-829. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Leafy spurge control and forage production after various fall-applied herbicide treatment rotations were evaluated in a bluegrass pasture and a mixed grass prairie. Dicamba at 2 kg ae/ha or picloram at 0.6 kg ae/ha alone or combined with 2,4-D at 1 kg ae/ha applied annually for 3 yr provided consistent leafy spurge control of 85% or better, but forage production was greater at the bluegrass pasture site than the mixed grass prairie site. Glyphosate plus 2,4-D at 0.4 plus 0.7 kg ae/ha applied annually or rotated with picloram plus 2,4-D or dicamba provided 90% or better leafy spurge control after 3 yr at the bluegrass pasture. Control was 50% or less at the mixed grass prairie site where forage production was severely reduced by glyphosate plus 2,4-D. All treatments on the bluegrass pasture provided a positive economic return averaging 227/ha after 3 yr. Picloram or picloram plus 2,4-D at the mixed grass prairie site provided net returns averaging 285/ha, but treatment rotations that included glyphosate plus 2,4-D one or more times in 3 yr averaged a net loss of 32/ha due to severe grass injury. |
| Title: Biology and host preference of Oxicesta geographica (Lepidoptera: Noctuidae) candidate agent for biological control of Euphorbia esula complex (Euphorbiaceae) in North America. |
| Author: Cristofaro-M {a}; Gassmann-A; Pecora-P. |
| Source: Environmental-Entomology. 1994; 23 (4) 1006-1012. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: The biology and host specificity of Oxicesta geographica F. from Romania, Hungary, and Southwestern Russia were studied to evaluate the potential of this moth as a new biological control agent of leafy spurge, Euphorbia esula L., "complex" in North America. This oligophagous, multivoltine tent caterpillar is common on perennial spurges in southeastern Europe and Asia Minor and prefers dry, open sites. Results of no-choice feeding tests with first instars on 93 plant species and biotypes, distributed in 33 families, show that O. geographica completed its life cycle mainly on plants of Euphorbia, subgenus Esula, and occasionally fed and developed on species in other subgenera of the genus. Studies of late instars did not show any important extensions of the host range. |
| Title: Pathogenicity of Agrobacterium species from the noxious rangeland weeds Euphorbia esula and Centaurea repens. |
| Author: Caesar-A-J. |
| Source: Plant-Disease. 1994; 78 (8) 796-800. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Disease surveys were made of Russian knapweed (Centaurea repens) and leafy spurge (Euphorbia esula), two noxious weeds that severely infest large areas of rangelands in the northern Great Plains. Strains of Agrobacterium tumefaciens were isolated from Russian knapweed exhibiting crown galls in New Mexico in 1991. Strains pathogenic to one or more of Helianthus annuus, Lycopersicon esculentum, Nicotiana tabacum, Datura stramonium, or Russian knapweed and known strains of biovars 1 and 2 of A. tumefaciens and A. vitis were inoculated on Russian knapweed and two other knapweed species, diffuse (C. diffusa) and spotted (C. maculosa). Some strains from New Mexico were strongly pathogenic to diffuse knapweed, causing rapidly developing galls that typically girdled, stunted, and caused death of the host. The biovar 1 strains were pathogenic to all three knapweed species, strains of biovar 2 were pathogenic to diffuse and spotted knapweed, and the single A. vitis strain was pathogenic only to diffuse knapweed, forming small galls. Stunted and chlorotic plants of leafy spurge with crown galls, collected in Glacier County, Montana, and plants with root galls collected in eastern North Dakota were infected with A. tumefaciens, which was identified as biovar 1. Leafy spurge plants exhibiting galls on roots collected in North Dakota were infected with strains identified as biovars 1 and 2. Host ranges among nine pathogenic strains from Russian knapweed, leafy spurge, and known strains representing biovars 1 and 2 of A. tumefaciens and A. vitis varied greatly, with six of the nine strains being pathogenic to no more than one additional species besides the original host. These findings indicate that A. tumefaciens may be effective as a biological control of these important rangeland weeds and especially of diffuse knapweed. |
| Title: Biology and host specificity of Chamaesphecia hungarica and Ch. astatiformis (Lep.: Sesiidae) two candidates for the biological control of leafy spurge, Euphorbia esula (Euphorbiaceae) in North America. |
| Author: Gassmann-A; Tosevski-I. |
| Source: Entomophaga-. 1994; 39 (2) 237-245. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Leafy spurge (Euphorbia esula (s.l.)) is an herbaceous perennial and serious weed of Eurasian origin that has been accidentally introduced into North America. The two European root-boring moths Chamaesphecia hungarica and Ch. astatiformis are univoltine and overwinter as mature larvae. Both species have a lower survival rate on leafy spurge than on their field hosts, and thus are not optimal candidates for the biological control of leafy spurge. However, the rate of larval development and larval growth on the target weed and on the two field hosts is nearly the same. The experimental host range of both species is restricted to a few species in the subgenus Esula within the genus Euphorbia. The two species occupy different habitats in the steppe biome and are targeted for similar leafy spurge habitats in North America. |
| Title: Organogenesis in leafy spurge (Euphorbia esula L.). |
| Author: Davis-David-G; Olson-Prudence-A. |
| Source: In-Vitro-Cellular-and-Developmental-Biology-Plant. 1993; 29P (3) 97-101. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: All parts of leafy spurge seedlings can be regenerated when isolated and placed onto B5 medium. One-centimeter isolated hypocotyl segments were tested successfully for their usefulness as a bioassay system by comparing the response of auxins, herbicides, and cytokinins. Indole-3-acetic acid (IAA) was the most effective auxin to stimulate root formation. IAA was effective whether the hypocotyl segments remained on the same medium up to 60 days, or the segments were transferred to basal media after 2 or 5 days (pulse treatment). Pulse treatments with the other auxins resulted in stimulation of root formation; continuous or 5-day pulses or higher concentrations of indole-3-butyric acid, alpha-naphthalene-acetic acid and especially 2,4-dichlorophenoxyacetic acid and picloram formed excessive callus instead of roots. Picloram did not stimulate root formation, whether the treatment was continuous or pulse-treated. No roots formed with continuous picloram at 0.1 mg/liter or greater, but transfer to basal media did result in root and shoot formation at about 50% of the number formed on the controls. Lesser picloram concentrations had no effect. Shoots formed readily on untreated (control) segments, but continuous treatment with all three cytokinins, kinetin, zeatin, and zeatin riboside, increased the numbers of shoots about equally. Root formation was inhibited by the cytokinins at the higher concentrations (0.1 to 0.2 mg/liter). With the exception of a 5-day pulse of 0.04 mg/liter IAA, the auxins did not stimulate shoot formation, but generally inhibited shoot formation, even in pulse-treated cultures. |
| Title: Fall cultivation and fertilization to reduce winterhardiness of leafy spurge (Euphorbia esula). |
| Author: Lym-Rodney-G; Messersmith-Calvin-G. |
| Source: Weed-Science. 1993; 41 (3) 441-446. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Reduced-tillage practices have allowed leafy spurge to infest cropland. The reduction in leafy spurge infestation and winterhardiness by fall tillage, IV application, or herbicide treatment was evaluated. Cultivating leafy spurge twice each fall for 3 yr provided complete control. Cultivation followed by N application at 225 kg ha-1 reduced the stand by 85% after 3 yr, whereas N applied alone had little effect. Picloram plus 2,4-D at 0.6 plus 1 kg ha-1 reduced the infestation to 65% of the untreated control after 2 yr but then the infestation declined rapidly to 1% after a third application. Leafy spurge cold tolerance decreased as root depth increased. The GR-50 and LT-50, the temperatures required to reduce total dry weight and survival, respectively, by 50% varied by root depth and treatment. For example, the LT-50 and GR-50 for untreated leafy spurge averaged -19 and lt -20 C for crowns, respectively, compared to the -16 and -18 C for roots from 0 to 15 cm deep and -13 and -12.5 C for roots from 15 to 30 cm deep. The GR-50 and LT-50 temperature after 2 yr of treatment was reduced to 0 C by two cultivations in fall or picloram plus 2,4-D. Carbohydrate content was not a good indicator of winterhardiness. Cultivation reduced the leafy spurge root system faster than herbicide treatment especially at the 15- to 30-cm depth. |
| Title: Leafy spurge (Euphorbia esula) control and grass injury with sulfometuron. |
| Author: Deane-W; Frank-Ronald-J; Henson-M-Ann; Peterson-Mark-A. |
| Source: Weed-Technology. 1993; 7 (1) 212-215. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Leafy spurge control with four herbicides was evaluated at nine sites in six Great Plains states (USA). Sulfometuron alone did not control leafy spurge satisfactorily 12 mo after treatment (MAT). Sulfometuron plus dicamba at 105 plus 2240 g ai ha-1, when spring- or fall-applied, averaged 26 and 89% control and 31 and 86% grass injury, respectively, 12 MAT. Sulfometuron plus picloram at 105 plus 560 g ai ha-1, when spring- or fall-applied, averaged 63 and 92% control and 19 and 89% grass injury, respectively, 12 MAT. |
| Title: Effect of 2,4-D on leafy spurge (Euphorbia esula) viable seed production. |
| Author: Al-Henaid-Jamal-S {a}; Ferrell-Mark-A {a}; Miller-Stephen-D. |
| Source: Weed-Technology. 1993; 7 (1) 76-78. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Leafy spurge viable seed production and germination were reduced by 2,4-D applied during flower development and seed formation, in the field. Viable seed production was reduced when 2,4-D was applied at all growth stages after the start of flower bud development. The number of viable seed from untreated plants was 173, while, the number of viable seed from plants treated 0, 7, 14, 21, 28, or 35 d after the start of flower bud development was lt 1, 4, 7, 31, 53 and 62; respectively. Leafy spurge seed germination was higher in gibberellic acid than in water for seed collected from untreated plants and from plants treated with 2,4-D 7, 14, and 21 d after bud initiation. This research shows that 2,4-D must be applied prior to flower bud development to prevent seed production. |
| Title: Recovery, germinability, and viability of leafy spurge (Euphorbia esula) seeds ingested by sheep and goats. |
| Author: Lacey-John-R; Wallander-Rosie; Olson-Rutz-Kathrin. |
| Source: Weed-Technology. 1992; 6 (3) 599-602. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Germinability and viability of leafy spurge seeds following ingestion by sheep and goats were evaluated. Four sheep and four goats were separated into eight pens and fed individually a known number of leafy spurge seeds. Following ingestion, goats and sheep passed leafy spurge seeds for 4 and 9 d, respectively. Eighteen percent of the seeds fed were recovered in the fecal material of both species of livestock. Number of seeds recovered, expressed as percent of total seeds fed, decreased with time (P lt 0.01). Germinability and viability of the recovered seeds were less than the control (P lt 0.01). Sheep were more effective than goats in reducing germinability and viability of leafy spurge seeds (P lt 0.01). Results indicate that sheep and goats are effective biological tools for reducing spread of leafy spurge seeds. However, animals grazing mature leafy spurge should be confined by 5 d, until all viable seeds have passed through the digestive system, before they are rotated onto pastures that are devoid of leafy spurge. |
| Title: Leafy spurge control and herbicide residue from annual picloram and 2,4-d application. |
| Author: Lym, R.G., and C.G. Messersmith. |
| Source: J. Range Mgmt. 40 (3): 194-198. |
| Source Type: Journal |
| Publication Date: 1987 |
| Abstract: NA |
| Title: Biological control update. |
| Author: Pemberton, R. |
| Source: Leafy Spurge News, R. Lorenz, Ed. Ag. Exp. Sta. Coop. Ext. Ser. 7 (1): 3. |
| Source Type: Report |
| Publication Date: 1986 |
| Abstract: NA |
| Title: The use of 2, 4-D as a set-up treatment prior to light rates of picloram for leafy spurge shoot control. |
| Author: Gamal, H. |
| Source: Proceedings of the Leafy Spurge Conference, Bozeman, MT. |
| Source Type: Paper |
| Publication Date: 1986 |
| Abstract: NA |
| Title: Progress and prospects for plant pathogens to control leafy spurge. |
| Author: Bruckart, W.R. |
| Source: Leafy Spurge News, R. Lorenze, Ed. Ag. Exp. Sta. Coop. Ext. Ser. NDSU. Fargo, ND 7(2): 5-6. |
| Source Type: Report |
| Publication Date: 1986 |
| Abstract: NA |
| Title: Efficacy and economics of leafy spurge (Euphorbia esula) control in pastures. |
| Author: Gylling, S.R., and W.E. Arnold. |
| Source: Weed Science 33:381-385. |
| Source Type: Journal |
| Publication Date: 1985 |
| Abstract: NA |
| Title: Leafy spurge distribution, biology, and control. |
| Author: Lacey, C.A., P.K. Fay, R.G. Lym, C.G. Messersmith, B. Maxwell, and H.P. Alley. |
| Source: Montana State U. Coop. Ext. Serv. Circ. 309. |
| Source Type: Book |
| Publication Date: 1985 |
| Abstract: NA |
| Title: Ranchers control leafy spurge. |
| Author: Lacey, C.A., R.W. Kolt, and P.K. Fay. |
| Source: Rangelands 6(5):202-204. |
| Source Type: Journal |
| Publication Date: 1984 |
| Abstract: NA |
| Title: Control of leafy spurge with herbicides. |
| Author: Lym, R.G., and C.G. Messersmith. |
| Source: North Dakota Farm Research Bull. 40 (5):16-19. |
| Source Type: Report |
| Publication Date: 1983 |
| Abstract: NA |
| Title: Leafy spurge identification and control. |
| Author: Eberlein, C.V., R.G. Lym, and C.G. Messersmith. |
| Source: North Dakota Ag. Exp. Sta. Circ. w-765. 4 pp. |
| Source Type: Report |
| Publication Date: 1982 |
| Abstract: NA |
| Title: Leafy spurge control and reestablishment after herbicide treatment. Ph. D. thesis, North Dakota State University. 88 pp. |
| Author: Bybee, T.A. |
| Source: B |
| Source Type: NA |
| Publication Date: 1981 |
| Abstract: |
| Title: Control of leafy spurge (Euphoribia esula) in Nebraska with the spurge hawkmoth (Hyles euphorbiae). |
| Author: Forwood, J.R., and M.K. McCarty. |
| Source: Weed Science 28(3): 235-240. |
| Source Type: Journal |
| Publication Date: 1980 |
| Abstract: NA |
| Title: Investigations on Oberea erythrocephala (Shrank) (Col;Cerambycidae), a possible biocontrol agent of leafy spurge Euphorbia spp. (Euphorbiaceae) in Canada. |
| Author: Shroeder, D. |
| Source: Zeit. fur ang. Ent. 90:237-254. |
| Source Type: Journal |
| Publication Date: 1980 |
| Abstract: NA |
| Title: The distribution of leafy spurge (Euphorbia esula) and other weedy Euphorbia spp. in the United States. |
| Author: Dunn, P.H. |
| Source: Weed Sci. 27:509-516. |
| Source Type: Journal |
| Publication Date: 1979 |
| Abstract: NA |
| Title: The social and economic impacts of leafy spurge in Montana. |
| Author: Reilly, W., and K.R. Kaufman. |
| Source: Pages 21-24 in Proc. Leafy Spurge Sump. North Dakota Coop. Ext. Serv. Fargo, ND. 84 pp. |
| Source Type: Report |
| Publication Date: 1979 |
| Abstract: NA |
| Title: Three years leafy spurge control trials with herbicides. |
| Author: Mitich, L.W. |
| Source: Res. Rep., North Central Weed Contr. Conf. 29:32-33. |
| Source Type: Journal |
| Publication Date: 1972 |
| Abstract: NA |
| Title: Projects in biological control of weeds. Pp. 656-600 in DeBach, P., ed. Biological Control of Insect Pests and Weeds. |
| Author: Holloway, J.K. |
| Source: Chapman and Hall Ltd. London. 844 pp. |
| Source Type: Book |
| Publication Date: 1964 |
| Abstract: NA |
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