The Search for Effective Biological Control Agents in Europe: History and Lessons from Leafy Spurge (Euphorbia esula L.) and Cypress Spurge (Euphorbia cyparissias L.)

1995 ◽  
Vol 5 (3) ◽  
pp. 466-477 ◽  
Author(s):  
A. Gassmann ◽  
D. Schroeder
Keyword(s):  
Biological Control ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Biological Control Agents ◽  
Euphorbia Cyparissias

Integrated Leafy Spurge (Euphorbia esula) Control Using Imazapic, Aphthona spp. Biological Control Agents, and Seeded Native Grasses

2008 ◽  
Vol 1 (3) ◽  
pp. 255-264 ◽  
Author(s):  
Laurie A. Richardson ◽  
Chelsea J. Juricek ◽  
Rodney G. Lym ◽  
Donald R. Kirby ◽  
Dwight A. Tober
Keyword(s):  
Biological Control ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Native Grasses ◽  
Biological Control Agents

Integrating Flea Beetles (Aphthonaspp.) with Herbicide and Grasses for Leafy Spurge (Euphorbia Esula) Management

2008 ◽  
Vol 22 (3) ◽  
pp. 523-529 ◽  
Author(s):  
Ankush Joshi
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Leafy Spurge ◽  
Control Agent ◽  
Euphorbia Esula ◽  
Grass Species ◽  
Stem Density ◽  
Biological Control Agents ◽  
Single Application ◽  
Sheyenne National Grassland

Most management tactics used against leafy spurge are not economical, practical, or efficacious when used alone. Combinations of the biological control agent,Aphthonabeetles, the herbicide imazapic (105 g/ha), and interseeded native grass species were evaluated for leafy spurge management at two sites: Sheyenne National Grassland and Ekre Grassland Preserve in North Dakota during 2001 to 2005. At the Sheyenne site, over a 5-yr study period, leafy spurge was reestablishing its stem density after a single application of imazapic, but stand suppression was maintained to < 11 stems/m2when management combined imazapic withAphthonaor interseeding of native grasses.Aphthonabeetles established at the Sheyenne site, but declined as leafy spurge density decreased. However, the remainingAphthonapopulation continued to suppress leafy spurge density. Leafy spurge stem control was successfully maintained for 3 yr byAphthonaand grass competition without repetition of the imazapic treatment. Leafy spurge root dry weights were reduced by 66% (< 111g/m2) in the insect plots during this period. At the Ekre site, similar results were observed for the first 3 yr. However, in the fourth yr, a failure of biological control agents to establish resulted in the resurgence of leafy spurge. During this study, lowerAphthonaemergence was observed in imazapic-treated plots, possibly due to reduced leafy spurge density.

Cytogenetic studies of leafy spurge, Euphorbia esula, and its allies (Euphorbiaceae)

1988 ◽  
Vol 66 (11) ◽  
pp. 2247-2257 ◽  
Author(s):  
A. E. Stahevitch ◽  
C. W. Crompton ◽  
W. A. Wojtas
Keyword(s):  
Seed Germination ◽  
Chromosome Number ◽  
Natural Populations ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Meiotic Abnormalities ◽  
Stability Studies ◽  
Polymorphic Species ◽  
Cytogenetic Studies ◽  
Euphorbia Cyparissias

Cytological and cytogenetic studies were carried out on populations of leafy spurge (Euphorbia esula L. s.l.) and its allies primarily from North America but also from Europe. Chromosome numbers were determined for 126 samples of E. esula, 11 of E. cyparissias L., 1 of the hybrid (E. ×pseudoesula Schur) between these two species, and 1 of E. agraria Bieb. All plants of E. esula were hexaploid. Of the total, 125 leafy spurge accessions had a chromosome number of n = 30; 1 of n = 25++. Very few meiotic abnormalities were observed. Euphorbia cyparissias was primarily tetraploid (n = 20), although occasional diploids (n = 10) were encountered. Tetraploids were fertile; diploids were sterile. The hybrid between the two foregoing species had a chromosome number of n = 25, indicating that the E. cyparissias parent was a tetraploid; meiosis in the hybrid was abnormal. Euphorbia agraria was found to have a gametic number of n = 20, which is the first chromosome number determination for this species; meiosis was normal. Artificial crosses were made successfully between 31 accessions of leafy spurge. Seed germination of the F1 progeny slightly exceeded that reported for natural populations, and meiosis was normal. Pollen stability studies were carried out on herbarium material. Stainability was 100% for most of the samples studied. Extensive pollen size polymorphism was found. It is suggested that this phenomenon supports the hypothesis that E. esula is of allopolyploid origin. No cytological or cytogenetic basis was found for considering the leafy spurge accessions examined in this study as other than as a single, albeit somewhat polymorphic, species.

Phenology of first and peak emergence of Aphthona lacertosa and A. nigriscutis: Two flea beetles introduced for biological control of leafy spurge, Euphorbia esula L.

2006 ◽  
Vol 37 (3) ◽  
pp. 382-391 ◽  
Author(s):  
Luke C. Skinner ◽  
David W. Ragsdale ◽  
Richard W. Hansen ◽  
Monika A. Chandler ◽  
Greg Spoden
Keyword(s):  
Biological Control ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Flea Beetles ◽  
Aphthona Lacertosa

Description of EuropeanChamaespheciaspp. (Lepidoptera: Sesiidae) feeding onEuphorbia(Euphorbiaceae), and their potential for biological control of leafy spurge (Euphorbia esula) in North America

1996 ◽  
Vol 86 (6) ◽  
pp. 703-714 ◽  
Author(s):  
I. Tosevski ◽  
André Gassmann ◽  
D. Schroeder
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Habitat Type ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Main Root ◽  
Male And Female ◽  
South Eastern Europe ◽  
Similar Survival

AbstractThe description of the tenChamaespheciaspecies associated withEuphorbiain 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. MostChamaespheciaspecies 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 eightChamaespheciaspp. investigated feed and develop in the roots of North American leafy spurge,Euphorbia esulasensu lato. Of these, the best candidate for the biological control of leafy spurge isC. crassicornis, because the larvae have a similar survival rate on the target weed and the European host-plant,E. virgata.

Morphometric studies of the Euphorbia esula group (Euphorbiaceae) in North America

1990 ◽  
Vol 68 (9) ◽  
pp. 1978-1988 ◽  
Author(s):  
C. W. Crompton ◽  
A. E. Stahevitch ◽  
W. A. Wojtas
Keyword(s):  
North America ◽  
Morphological Characters ◽  
Leafy Spurge ◽  
Principal Coordinate Analysis ◽  
Euphorbia Esula ◽  
Eastern North America ◽  
Single Variable ◽  
Authentic Material ◽  
Variable Species ◽  
Euphorbia Cyparissias

Leafy spurge and cypress spurge are important weeds of pastures and unimproved rangeland in western and eastern North America, respectively. Taxonomists disagree as to whether leafy spurge is a single variable species or an aggregate of two or more species. Morphometric techniques (clustering by incremental sum of squares and principal coordinate analysis) were used to analyze relationships in leafy spurge and its allies. On the basis of studying 26 morphological characters found in 200 collections representing 32 putative taxa, we concluded that in North America only four species should be recognized, namely, Euphorbia agraria Bieb., Euphorbia cyparissias L., Euphorbia esula L., and Euphorbia ×pseudoesula Schur. A key to these taxa is provided. No authentic material of Euphorbia lucida Waldst. & Kitt. and Euphorbia salicifolia Host was found from this continent in the collections we examined.

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