scholarly journals Application of chemotaxonomy of leafy spurges (Euphorbia spp.) in biological control

1992 ◽  
Vol 70 (8) ◽  
pp. 1529-1536 ◽  
Author(s):  
Antony N. G. Holden ◽  
Paul G. Mahlberg

Triterpenoid profiles from latex of 56 accessions of European leafy spurges (Euphorbia spp.) were analyzed by gas–liquid chromatography. Qualitative and quantitative differences for components of the profiles were employed to distinguish between accessions. Triterpenoid profiles were diagnostic for the species, E. amygdaloides, E. agraria, E. cyparissias, E. lucida, and E. seguierana and were similar for each of these species in accessions collected from distant areas of Europe. By contrast, the 37 accessions of the E. esula complex were separated into 15 groups on qualitative and quantitative differences for components in the profiles. Identical profiles were detected among neighbouring accessions as well as those in collections from widely distant sites; conversely, different profiles also were identified for such collections. Profiles among these groups were compared with profiles of 39 United States (US) accessions of leafy spurge from Montana, Nebraska, North Dakota, and South Dakota. Profiles of US accessions, which were less variable than those from Europe, grouped into only 3 of the 15 European groups, whereas one US group could not be placed directly into a European group. This study demonstrates that latex analyses of European leafy spurges can distinguish between spurge populations and will identify potential plant sources of biocontrol agents for application against their leafy spurge counterparts in North America. Key words: leafy spurge, Euphorbia, latex, triterpenoids, gas–liquid chromatography.

1965 ◽  
Vol 38 (3) ◽  
pp. 674-676
Author(s):  
Ya M. Slobodin ◽  
V. E. Mayorova ◽  
A. M. Smirnova

Abstract 1. Degradation of SKEP was carried out. 2. The qualitative and quantitative compositions of C2-C6 hydrocarbons in the products of degradation were established by gas-liquid chromatography.


Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Jim M. Story ◽  
Robert M. Nowierski ◽  
Keith W. Boggs

A survey was conducted at 88 sites in Montana in 1984 and 1985 to determine the distribution of Urophora affinis Frauenfeld and U. quadrifasciata (Meigen), two seed head flies released on spotted knapweed (Centaurea maculosa Lam. # CENMA) in North America. U. affinis, released in Montana during 1973 to 1977, was found at 40 of the 88 sites. The fly was concentrated within a short radius (about 5 to 8 km) of release sites, even at sites having well-established populations. U. quadrifasciata, released in British Columbia in 1972, but not in the United States, was found at 84 sites. The data suggest that the fly entered the state in the northwest corner and dispersed in a southeasterly direction. There was a strong positive relationship between mean number of galls per seed head and percent infestation for both fly species.


1959 ◽  
Vol 91 (2) ◽  
pp. 116-121 ◽  
Author(s):  
J. Morris Smith

Linaria vulgaris Mill., known commonly as toadflax or butter-and-eggs, is worldwide in its distribution but is a serious weed only in the Canadian provinces of Alberta, Saskatchewan, and Manitoba (Zilke and Coupland, 1954), where it is increasing in importance (Beck, 1954; Carder, 1956; Forbes, 1957). Smith (1956) correlated its relative insignificance as a weed in the other provinces and in the northwestern United States with the occurrence of the curculionid beetle Gylmnaetron antirrhini (Payk.). Investigations on this and other insects that feed on toadflax and an evaluation of their possible use as biological control agents are reported in this paper; also included are some observations on the weedand its natural enemies made since 1950 in all provinces west of Quebec and in the northwestern United States.


2019 ◽  
Vol 113 (2) ◽  
pp. 622-632 ◽  
Author(s):  
Michael I Jones ◽  
Juli R Gould ◽  
Hope J Mahon ◽  
Melissa K Fierke

Abstract Biological control offers a long-term and sustainable option for controlling the destructive forest pest emerald ash borer (EAB), Agrilus planipennis Fairmaire, in North America. Three larval parasitoids, Spathius agrili Yang (Hymenoptera: Braconidae), Tetrastichus planipennisi Yang (Eulophidae), and Spathius galinae Belokobylskij & Strazanac, have been introduced to North America from the native range of EAB (northeastern Asia). While T. planipennisi appears to be persisting where it has been introduced in northern United States, S. agrili failed to establish in northeastern states. The more recently identified parasitoid S. galinae was recovered from the Russian Far East and climate matching suggests it should be suited for release in colder climates. We collected data on the phenology of EAB and its introduced larval parasitoids from colonies established in an insectary, growth chambers, and field-caged trees in Syracuse, New York to determine whether asynchrony between parasitoids and EAB or climate could impact establishment and persistence. Phenological data indicated EAB has one and 2-yr life cycles in New York, with parasitoid-susceptible EAB larvae available spring to fall for parasitism. Insectary and growth chamber studies indicated S. galinae and T. planipennisi were synchronous with EAB phenology, and field studies suggested both species could overwinter in northeastern climates. Spathius agrili was asynchronous with EAB phenology and climate, emerging when fewer parasitoid-susceptible EAB larvae were available and temperatures were not optimal for survival. Our results suggest S. galinae and T. planipennisi are suited for biological control of EAB at the northern limits of its range in North America.


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