Dutch elm disease

The phenolic and glycoprotein metabolites of C. ulmi cause the wilting and death of the tree. However, the beetles are deterred from feeding and using as 

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The fungus responsible for Dutch elm disease is spread by European bark beetles when they burrow into the tree Other beetles congregate at the site attracted by the scent of a mixture of chemicals some emitted by other beetles and some coming from the tree One of the compounds given off by female bark beetles is 4 methyl 3 heptanol Suggest an efficient synthesis of this pheromone from alcohols of five carbon atoms or fewer... 

Antimycin A is effective against Altemaria solani spores(42)5 karumin is effective against Rhizoctonia solani ( iD. Nikkomycin is being used to cure trees of Dutch elm disease in Hamden, Connecticut(44). It inhibits the formation of chitin and stops the myceTia of Ceratocy-stis ulmi from growing normally. 

The U.S. Forest Service scientists in New York have isolated and identified chemical sex attractants used by elm bark beetles that are responsible for transmitting the fungus causing Dutch elm disease. Examples of attractants are 2,4-dimethyl-5-ethyl-6,8-dioxabicyclo [3.2.1] octane (called multistriatin) and 4-methyl-3-heptanol. In field trials an artificially produced mixture of the compounds has proved attractive to the elm bark beetle. 

K.J. Stevenson, J.A. Slater and S. Takai, Cerato-ulmin, wilting toxin of Dutch Elm disease fungus, Phytochem. 18 (1979) 235-238. 

Multistriatin 1 is a pheromone of the elm bark beetle. This beetle distributes the fungus responsible for Dutch elm disease and it was hoped that synthetic multistriatin might trap the beetle and prevent the spread of the disease. It is a cyclic compound with two oxygen atoms both joined to the same carbon atom (C-6 in 1) and we call such ethers acetals. 

Uses as fungicide for control of a wide range of fungal diseases in cereals, fruit, vines, hops, ornamentals, vegetables, rice coffee, cotton, mushrooms, and other crops also used by trunk injection to give some control of Dutch elm disease. 

The pathogenic fungus Ceratocystis ulmi (C. ulmi), responsible for Dutch elm disease, causes a blockade in the vascular tissue that can lead to the eventual death of the... 

So why is DDT perceived as such a dangerous chemical In the USA DDT was used extensively after the war for the control of various insect pests. It was used in some cases in much greater quantities than it had been previously, and possibly such quantities were unnecessary. For example, i lb of DDT per acre had been sufficient to eradicate the malarial mosquito from swamps, yet in the control of the bark beetles, which carry Dutch Elm disease, 25 lb per acre were used in the USA for spraying the trees in some cases. The disease was devastating the trees, and perhaps some overkill was understandable, but this use of DDT led to effects on wildlife, with birds being noticeably affected. For example, the population... 

Stereoselective hydrogenation. A stereoselective synthesis has been reported of the naturally occurring form of a -multistriatin (5), the aggregation pheromone of the European elm beetle, the vector of Dutch elm disease in North America. The synthesis is another example of the value of carbohydrates as chiral precursors to natural products. In this case, the known epoxide 1, derived from D-glucose, was converted in several steps into 2. The crucial next step required hydrogenation to 3 with the 1,3-diaxial configuration of the two methyl groups. The desired selectivity was attained by use of Wilkinson s catalyst. 

Because most elms are susceptible to so many insects and diseases, you might want to avoid using them in the landscape. If you do decide to grow elms, consider planting lacebark elm (U. parvifolia), which is more resistant to Dutch elm disease and elm leaf beetles. Plant elms in spring or fall as bare-root or balled-and-burlapped trees. Full sun and well-drained soils are best. 

Bark tunneled. Cause Elm bark beetles. These Ao", dark reddish brown beetles attack weakened elm trees and serve as vectors of Dutch elm disease. The adult beetles bore small holes through the bark and lay eggs in... 

Damage Larvae and adults live in galleries engraved in a radiating pattern under the bark of elm trees. The tunneling does not cause serious damage to the trees. However, adults carry Dutch elm disease fungi on their bodies and infect healthy trees when they bore into bark. 

Control Maintain healthy trees bury or burn all diseased or dying elms in the area to eliminate sources of disease plant cultivars resistant to Dutch elm disease trap adult beetles with pheromone traps conserve braconid wasps Dendwsoterprotuberans), which were released in the eastern United States to parasitize the beetles. 

Many diseases can spread from one plant to the next only by means of a vector. A vector is an animal (usually an insect) that carries disease from one plant to the next. In such cases, if you can control the vector, the disease will not occur. Thus, one approach to controlling Dutch elm disease is to control the elm bark beetle, which spreads the disease from infected to healthy elms. 

Symptoms Dutch elm disease (DED) causes leaves to wilt, yellow, and drop early. Usually, branches show symptoms and die back one at a time. Sometimes the whole tree will wilt and die suddenly. 

Dusty miller. See Senecio Dutch elm disease (DED), 7,243,244, 245,366,394-95,394 Dwarf mistletoe, 354... 

Use Antiseptics, fungicide, recommended against Dutch elm disease. 

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