scholarly journals Dutch elm disease and elm bark beetles: a century of association

2015 ◽  
Vol 8 (2) ◽  
pp. 126-134 ◽  
Author(s):  
A Santini ◽  
M Faccoli
2005 ◽  
Vol 72 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M.B. Sticklen ◽  
M.G. Bolyard ◽  
R.K. Hajela ◽  
L.C. Dufresne

The folio wing review gives an overview of current research in the area of molecular and cellular interactions in Dutch elm disease. This vascular wilt disease is caused by the fungus Ophiostoma ulmi and is transmitted from diseased to healthy trees by the elm bark beetles. Fungal toxins are described which are associated with pathogenesis, one of which, ceratoulmin, is under investigation at the molecular level, particularly regarding its mode of action and localization. The fungus has also been examined at the molecular level to differentiate between aggressive and non-aggressive isolates on the basis of protein and nucleic acid profiles. Genetic linkage maps are being developed to correlate disruption of certain genes with the loss of pathogenicity. Viral and bacterial antagonists of the fungus, which may serve as biological control mechanisms for Dutch elm disease, have been characterized, as have several of the active molecules responsible for control. Host responses are also discussed at the molecular and biochemical level, including phytoalexins and defense mechanism elicitors. Several Unes of investigation are discussed to provide an overview of molecular approaches to understanding and manipulating the organisms involved with the ultimate goal of controlling Dutch elm disease.


1957 ◽  
Vol 89 (6) ◽  
pp. 275-280 ◽  
Author(s):  
R. J. Finnegan

The Dutch elm disease is caused by the fungus Ceratostomella ulmi (Schwartz) Buis. It was first reported in the United States at Cleveland, Ohio, in 1930 (ll), and has since spread westward to Colorado and northeastward into Vermont (22). It is believed that the disease was accidentally introduced into the United States from Europe, where it has caused heavy mortality of elms since its discovery in 1919 (7, 19, 20). In Canada the disease was first recorded by Pomerleau (14) at St. Ours, Que. This infection proved to be centred around Sorel, Que., and since it was isolated from the nearest known infection in the United States by approximately 200 miles, is regarded as a separate introduction from Europe. The Sorel infection spread very rapidly, and by the end of 1950, the area between Montreal, Quebec City, and Sherbrooke was heavily infested by the fungus (17). I t has since spread westward as far as Ottawa and Kingston in 0ntario (16).


1996 ◽  
Vol 128 (3) ◽  
pp. 435-441 ◽  
Author(s):  
I.L. Pines ◽  
A.R. Westwood

AbstractThe native elm bark beetle, Hylurgopinus rufipes (Eichhoff), is the major vector of Dutch elm disease, Ophiostoma ulmi (Buisman) Nannf., in Manitoba. The herbicide Glowon™, monosodium methane arsenate (MSMA), was applied to a chainsaw cut in American elm, Ulmus americana L., tree stems to determine if the treated elms would become effective trap trees for H. rufipes. Three treatments were compared: treated with herbicide and girdled, girdled, and control. All herbicide-treated elms died within 18 days after application. Significantly higher numbers (P < 0.01) of native elm bark beetles were attracted to the herbicided elms, compared with the other treatments. Beetles bred only in the elms treated with herbicide. Of the total brood galleries constructed, 72% had no egg hatch while the remaining 28% had larval tunnels. Progeny adults emerged from less than 1% of the larval tunnels. MSMA application could supplement the Dutch elm disease management program in Manitoba.


2008 ◽  
Vol 34 (2) ◽  
pp. 116-122
Author(s):  
Irene Pines ◽  
Richard Westwood

Six mark-recapture experiments were conducted in Manitoba, Canada, to determine the effectiveness of fluorescent powder to mark emerging native elm bark beetle adults, Hylurgopinus rufipes (Eichoff) (Coleoptera: Scolytidae), the vector of Dutch elm disease, Ophiostoma novo-ulmi (Brazier), after departure from overwintering sites in spring and emergence from broodwood in summer. Native elm bark beetles marked themselves on emergence from overwintering sites and summer trap logs. The spring and summer periods of flight activity for unmarked and marked beetles were similar. Marked beetles were captured over 1 month after peak emergence in the spring and 2 months after emergence from trap logs in the summer. Marked beetles were captured up to 1 km (0.6 mi) from release sites. Where integrated Dutch elm disease management activities are implemented in buffer zones to minimize the number of elm bark beetles entering community urban forests, buffer zones should be a minimum of 1 km (0.6 mi) in width.


2009 ◽  
Vol 97 (2) ◽  
pp. 219-227 ◽  
Author(s):  
John C. Moser ◽  
Heino Konrad ◽  
Stacy R. Blomquist ◽  
Thomas Kirisits

DDT Wars ◽  
2015 ◽  
Author(s):  
Charles F. Wurster

The robin was twitching, tremoring, convulsing uncontrollably, and peeping occasionally. The student handed the bird to me, and in a few minutes it was dead in my hands. It was April 23, 1963, and I was in my laboratory at Dartmouth College in Hanover, New Hampshire, when the student walked in with the bird. A week earlier the elm trees of Hanover had been sprayed with the insecticide DDT to control the spread of Dutch elm disease by elm bark beetles. In the following weeks 151 dead birds filled my freezer, many of them exhibiting before they died the tremors that we later learned were typical of DDT poisoning. Four of us were conducting a small-scale study of the effects, if any, of the DDT spray program in Hanover. We were shocked by what was happening to the local birds, but we would have expected this reaction to DDT if we had read the scientific literature on earlier DDT spray programs on elm trees. We had not. We soon realized that we had rediscovered what other ornithologists had already reported from DDT spray programs in the American Midwest. We also soon learned that DDT was ineffective in preventing the spread of Dutch elm disease and that another procedure, sanitation without insecticides, effectively protected the elms. This DDT spray procedure was all costs and no benefits. Hundreds of towns were killing thousands or millions of birds while not protecting their elms. The whole thing struck me as absurd and tragic. It became a life-changing event for me. I decided that DDT was a chemical that had to be stopped, although I hadn’t the slightest idea where such a conclusion was going to lead. I was 33 years old and had become what in those days was usually called a conservationist. Now such people have been renamed “environmentalists.” I had a dubious beginning as such a person. When I was about seven and living in a northern suburb of Philadelphia, I came across a couple of snakes.


1973 ◽  
Vol 51 (9) ◽  
pp. 1565-1571 ◽  
Author(s):  
James L. Harris ◽  
Willard A. Taber

Ceratocystis ulmi, the Ascomycete responsible for Dutch elm disease, may sporulate by means of a distinctive structure, the synnema, common in nature in the tunnels of elm bark beetles. Developmental stages of this structure and its spores were examined by light microscopy, by conventional transmission electron microscopy of thin sections and freeze-etch replicas, and by scanning electron microscopy of whole spores and fruiting structures. The synnema is a tight bundle of darkly pigmented hyphae growing erect from the substrate and terminated by a mass of colorless, wet spores. A layer of slime covering the hyphal bundle and random cross-connections between parallel hyphae appear to function in stabilization of the structure. Organelles typical of Ascomycetes fill the spores, vegetative hyphae, and young synnemal hyphae. However, in mature synnemal hyphae, the cytoplasmic contents degenerate, leaving only membranous vesicles in the partially collapsed hyphae. The spores contain large lipid droplets not found in either vegetative or synnemal hyphae indicating some differences in metabolism of spores and hyphae. Most synnemal spores form on sympodulae, but some spores form on intrahyphal hyphae.


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