Native Bark Research Articles

Mountain Pine Beetle Infestation: Cycling and Succession in Lodgepole Pine Forest

A research project was initiated in 1980 to study the effects of outbreaks of the mountain pine beetle (Dendroctonus ponderosae) on lodgepole pine forest (Pinus contorta spp. latifolia) in Yellowstone National Park and surrounding areas. This native bark beetle recently has killed millions of trees over thousands of square kilometers in the central and northern Rocky Mountains. Major outbreaks first occurred in Grand Teton National Park in the 1950's and in Yellowstone National Park in the 1960's. The outbreak in Yellowstone Park is still spreading.

Mountain Pine Beetle Infestation: Cycling and Succession in Lodgepole Pine Forest

A research project was initiated in 1980 to study the effects of outbreaks of the mountain pine beetle (Dendroctonus ponderosae) on lodgepole pine forests (Pinus contorta spp. latifolia) in Yellowstone National Park and surrounding areas. This native bark beetle recently has killed millions of trees over thousands of square kilometers in the central and northern Rocky Mountains. Major outbreaks first occurred in Grand Teton National Park in the 1950's and in Yellowstone National Park in the 1960's. The outbreak in Yellowstone Park is still spreading.

Attraction of the Native Elm Bark Beetle to American Elm After the Pruning of Branches12

During May and June more overwintering adults of Hylurgopinus rufipes (Eichhoff) were caught on American elms, Ulmus americana L., that had been pruned than on those that were not pruned. Fewer beetles were caught on pruned elms whose wounds were treated with dressing compound than on pruned elms with no wound dressing. The number of H. rufipes that were caught also varied with height above the ground; more beetles were caught at 3 m on elm trunks than at 2 or 4 m. After mid-July, there was no significant difference in the number of summer-emerging H. rufipes caught on pruned elms compared with that on unpruned elms.

SEASONAL ACTIVITY OF THE NATIVE ELM BARK BEETLE, HYLURGOPINUS RUFIPES, IN CENTRAL ONTARIO (COLEOPTERA: SCOLYTIDAE)

AbstractDaily trapping of native elm bark beetles, Hylurgopinus rufipes (Eichh.), in central Ontario showed that the population is divided into fairly discrete overwintering adult and larval groups. Group proportions depend on the stage of development of the local beetle infestation and disease infection. Both beetles and disease are spread by mass movement of beetles, in late summer and fall, in search of living elm trees in which to feed and overwinter.

Seasonal development of Dutch elm disease on white elms in central Ontario, Canada. II. Following feeding by the North American native elm bark beetle

Adults of the North American native elm bark beetle, Hylurgopinus rufipes, naturally infested with Dutch elm disease fungus, Ceratocystis ulmi, were caged on trunks of white elms (Ulmus americana) so that infection could be studied. In surveys made in 1971, expression of external symptoms of Dutch elm disease was observed on elms which had been caged with beetles during the period May 26 to July 9, 1971. Vascular discoloration (internal symptom expression), fungus spread, fungus contamination of beetles, and transmission of fungus to the host by beetles were pronounced on elms caged with beetles from June 3 to July 2. Ceratocystis ulmi was recovered from leaves of trees caged during the period May 26 to July 2. Until May 31, 1972, dieback and death resulting from infection were restricted to trees caged with beetles during June. Corresponding development of vascular discoloration and fungus spread in the host also occurred, mostly during the caging period in June. There was no appreciable change in beetle activity in xylem tissue during the period of experiment. These results suggest that the period of highest susceptibility of white elm to Dutch elm disease in 1971 in central Ontario was June 3 to July 2.Inoculation through feeding by caged beetles carrying C. ulmi is probably the method that most closely approximates natural infection.

A thermogravimetric study of the pyrolysis of the bark and chemically-modified bark of jack pine, pinus banksiana lamb

The pyrolysis of native jack pine bark has been studied from 200 to 340°C by thermogravimetric (TG), and isothermal weight-loss methods. The effects of particle size, solvent extraction and additions of zinc (II) and iron (III) chlorides on the pyrolysis behaviour have also been examined. The bark was characterized by infrared spectroscopy and low-temperature gas adsorption. Residues were analysed for CHN contents and structural changes which occurred on heating were examined by optical and scanning electron microscopy. The TG characteristics were not affected by solvent extraction or particle size variation while the metal chloride additions inhibited the loss of volatile materials from the bark probably by stabilizing chemical bonding in the bark components. Isothermal decomposition data were found to fit established kinetic expressions associated with inorganic decompositions. The physical mechanics of pyrolysis have been interpreted on the assumption that pyrolysis is initiated through the formation of planes of lateral strain which are sites for decomposition and which decrease in number inversely with time. It is suggested that these sites are produced by an oxidation mechanism which may be rate-controlling in the pyrolysis. This hypothesis is supported by the observation that the data fit a reaction rate compensation curve, often associated with oxidation processes but more generally with heterogeneous catalytic reactions. The compensation curve also relates the kinetic parameters found by other workers for a large variety of wood-derived materials.

Feeding Responses by Hylurgopinus rufipes1 to Combined Chemical and Physical Stimuli2

Feeding responses by adults of the native elm bark beetle, Hylurgopinus rufipes (Eichhoff) (Coleoptera: Scolytidae), on 1-mm-thick pith discs soaked in 10 mg of an 80% ethanol extract of trunk bark of Ulmus americana were significantly different (0.01 level) from the controls. The beetle fed only on chemically treated 1-mm-thick discs. Thus, the thigmotactic stimulus of such discs was a required component of the total stimulus for feeding by this insect. Feeding on a benzene extract of U. americana bark, or on p -hydroxybenzaldehyde, was not significantly different (0.05 level) from the control.

Measurement of Gas Exchange in Woody Plants

METHODS of controlling Dutch elm disease have been investigated at this laboratory for the past four years. Emphasis has been placed on two approaches to the problem of control. One approach has been the search for a suitable chemotherapeutant to control the causal agent, the fungus Ceratocystis ulmi (Buism) C. Moreau. The other approach has been the screening of systemic insecticides to control its vectors, the European elm bark beetle, Scolytus multistriatus (Marsham), and the native elm bark beetle, Hylurgopinus rufipes (Eich). A difficulty was found in methods of measuring the effects of chemotherapeutants and pesticides on diseased and healthy American elms, Ulmus americana L., in the laboratory under controlled conditions. A careful survey of existing literature showed that no device existed for measuring the effects of chemotherapeutants, pesticides and disease. Indeed, other workers in these fields have expressed and emphasized the lack of methods of measuring disease in woody plants1,2. This led us to investigate respiration as a means of studying the effects of chemotherapeutants and pesticides on woody plants.

Scolytid Vectors of the Dutch Elm Disease in Ontario

Although many possible vectors of the Dutch elm disease, Ceratocystis ulmi (Buism.) C. Moreau, have been listed by Collins et al. (1936) and others, only two, Scolytus multistriatus (Marsh.), the European elm bark beetle, and Hylurgopinus rufipes (Eichh.), the native elm bark beetle, are known to transmit the disease with any regularity. In this capacity alone thcse two species of beetles are important pests of elm. The persistent spread of the Dutch elm disease in southern Ontario (Hord and Quirke, 1955) made it imperative that adequate surveys be maintained to indicate yearly changes in the occurrence of the introduced vector, and to ascertain more precisely the distribution of the native vector relative to the distribution of elm in Ontario. Consequently the Forest Insect Survey of the Forest Insect Laboratory, Sault Ste. Marie, intensified its elm bark beetle program in 1956, and from then to 1959, 138 positive samples of these two scolytid beetles have been received. An analvsis of these records and their relationihip to the current incidence of the Dutch elm disease in Ontario are presented in this paper.

MEANS OF INOCULATION OF THE DUTCH ELM DISEASE BY HYLURGOPINUS RUFIPES EICHH.

Investigations on the transmission of the Dutch elm disease were carried out during summer of 1946 in Canada, where the only known vector of the fungus is the native bark beetle, Hylurgopinus rufipes. By close observations of young elms, recently and naturally infected with Ceratostomella Ulmi, it was found that by boring tunnels through the thin bark of twigs or small branches to the cambium, the adults of this beetle can inoculate the disease to healthy trees.

Studies on the Larvae of the Native Elm Bark Beetle

Studies on the Larvae of the Native Elm Bark Beetle