Photochemical oxidant injury and bark beetle (Coleoptera: Scolytidae) infestation of Ponderosa pine: II. Effect of injury upon physical properties of oleoresin, moisture content, and phloem thickness
AuthorsF. W. Cobb
D. L. Wood
R. W. Stark
P. R. Miller
Authors AffiliationsF. W. Cobb, Jr. was Assistant Professor, Department of Plant Pathology, Berkeley; D. L. Wood was Associate Professor, Department of Entomology and Parasitology, Berkeley; R. W. Stark was Professor, Department of Entomology and Parasitology, Berkeley; P. R. Miller was Plant Pathologist, Pacific Southwest Forest Experiment Station, Riverside.
Hilgardia 39(6):127-134. DOI:10.3733/hilg.v39n06p127. May 1968.
Certain aspects of insect-disease relationships, especially those concerning transmission of pathogens, have been studied extensively and their significance has been well established. However, the role of diseases as factors predisposing coniferous trees to bark beetle infestation has received only minor attention. There has been little effort to determine the extent of the association between disease and bark beetle infestation, the significance of predisposing diseases in the ecology of the beetles, or the effects of disease upon the host that may increase susceptibility to beetle attack.
The series of papers in this issue presents the results of studies to determine (a) the degree of association between photochemical atmospheric pollution injury to ponderosa pine and infestation by bark beetles (paper I), and (b) the changes in the physiology of diseased trees which might influence host susceptibility to bark beetles (papers II and III). The results show that oxidant injury does, in fact, predispose ponderosa pine to beetle infestation, and that the injury leads to physiological changes in the host which may be related to increased bark beetle susceptibility. The significance of these results in relation to the present knowledge on bark beetle ecology and host susceptibility is discussed in paper IV.
Bier J. E. The relation of bark moisture to the development of canker diseases caused by native, facultative parasites I. Cryptodiaporthe canker of willow. Canad. Jour. Bot. 1959. 37:229-38.
Bushing R. W., Wood D. L. Rapid measurement of oleoresin exudation pressure in Pinus ponderosa Laws. Canad. Ent. 1964. 96:510-13.
Vité J. P. The influence of water supply on oleoresin exudation pressure and resistance to bark beetle attack in Pinus ponderosa. Contrib. Boyce Thompson Inst. 1961. 21:37-66.
Vité J. P., Wood D. L. A study of the applicability of the measurement of oleoresin exudation pressure in determining susceptibility of second growth ponderosa pine to bark beetle infestation. Contrib. Boyce Thompson Inst. 1961. 21:67-78.
Also in this issue:Photochemical oxidant injury and bark beetle (Coleoptera: Scolytidae) infestation of Ponderosa pine: I. Incidence of bark beetle infestation in injured trees
Photochemical oxidant injury and bark beetle (Coleoptera: Scolytidae) infestation of Ponderosa pine: III. Effect of injury upon oleoresin composition, phloem carbohydrates, and phloem pH
Photochemical oxidant injury and bark beetle (Coleoptera: Scolytidae) infestation of Ponderosa pine: IV. Theory on the relationships between oxidant injury and bark beetle infestation