Virulence of, and interactions among, mountain pine beetle associated blue-stain fungi on two pine species and their hybrids in Alberta

2007 ◽  
Vol 85 (3) ◽  
pp. 316-323 ◽  
Author(s):  
A.V. Rice ◽  
M.N. Thormann ◽  
D.W. Langor

Mountain pine beetle (MPB) is the most serious pest of lodgepole pine in western Canada, and it is predicted to spread into boreal jack pine within the next few years. Colonization of host trees by MPB-associated blue-stain fungi appears to be required for successful beetle reproduction. Three species of blue-stain fungi, Grosmannia clavigera (Robinson-Jeffery and Davidson) Zipfel, de Beer, and Wingfield (≡ Ophiostoma clavigerum (Robinson-Jeffery and Davidson) Harrington), Ophiostoma montium (Rumbold) von Arx, and Leptographium longiclavatum Lee, Kim, and Breuil, are associated with MPB in Alberta. In inoculation experiments, all three fungi caused lesions on lodgepole pine, jack pine, and their hybrids. On average, lesions were longer on jack pine and hybrids than on lodgepole pine, suggesting that fungal development will not be a barrier to MPB success in these trees. Differences in lesion length caused by the three fungal species were minimal, with significant differences observed only on hybrid pine and between O. montium and the other fungal treatments. On average, lesions caused by combinations of the three fungi (pair-wise and all together) did not differ significantly in length from those caused by the fungi singly, and none of the fungal species competitively excluded any of the others. These observations suggest that all three species are pathogenic to boreal pines and that the virulence of all three species is comparable.

1987 ◽  
Vol 65 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H. S. Whitney ◽  
R. J. Bandoni ◽  
F. Oberwinkler

A new basidiomycete, Entomocorticium dendroctoni Whitn., Band. & Oberw., gen. et sp. nov., is described and illustrated. This cryptic fungus intermingles with blue stain fungi and produces abundant essentially sessile basidiospores in the galleries and pupal chambers of the mountain pine bark beetle (Dendroctonus ponderosae Hopkins Coleoptera: Scolytidae) in lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.). The insect apparently disseminates the fungus. Experimentally, young partially insectary reared adult beetles fed E. dendroctoni produced 19% more eggs than beetles fed the blue stain fungi.


1990 ◽  
Vol 20 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Y. Yamaoka ◽  
R. H. Swanson ◽  
Y. Hiratsuka

In two separate experiments in the field, healthy 80-year-old lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) were inoculated with four blue-stain fungi that are associated with mountain pine beetle (Dendroctonusponderosae Hopk.) and beetle-attacked trees. Inocula of Ophiostomaclavigerum (Robins.-Jeff. & Davids.) Harrington, O, huntii (Robins.-Jeff.) de Hoog & Scheffer, O. montium (Rumb.) von Arx, and O. minus (Hedge.) H. & P. Sydow were prepared on sawdust media. Inoculum was placed under the bark in two areas (8 × 5 cm each), one above the other, separated by a 15-cm space in which heat pulse velocity (HPV) sensors were installed. HPVs in the inoculated trees were monitored daily for 4 weeks. In sections inoculated with O. clavigerum, HPVs were significantly reduced 10 to 13 days after inoculation in both experiments. Sapwood under the inoculated area was visibly altered and colonized by the fungus. The other three fungi did not significantly reduce HPVs. These results proved the capability of O. clavigerum to colonize functional sapwood and stop sap flow within a short period of time and reconfirmed the importance of this fungus in the mortality of trees attacked by mountain pine beetle.


1979 ◽  
Vol 9 (3) ◽  
pp. 323-326 ◽  
Author(s):  
Robert D. Harvey Jr.

Recently killed lodgepole pine (Pinuscontorta Dougl.) were examined to determine rate of spread of blue stain fungi introduced by mountain pine beetle (Dendroctonusponderosae Hopk.). Trees were felled, dissected at 2.5-m intervals, and photographed at each cross section to determine area of stain. Rate of spread is so rapid that salvaging mountain pine beetle killed lodgepole pine prior to severe staining is difficult.


1995 ◽  
Vol 73 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Halvor Solheim

Invasion of lodgepole pine sapwood by blue-stain fungi was followed for 7 weeks after infestation by the mountain pine beetle, Dendroctonus ponderosae. During this period all sapwood was heavily stained blue and blue-stain fungi were always isolated close to the front of visible occlusion. Ophiostoma clavigerum and Ophiostoma montium were commonly isolated, both of which are known to be carried in the mycangia of the mountain pine beetle. Ophiostoma montium was most frequently isolated, but when both fungi were present O. clavigerum was always at the leading edge of fungal penetration. On average O. montium trailed 7.3 mm behind O. clavigerum. Other microorganisms were seldom isolated. Key words: lodgepole pine, Dendroctonus ponderosae, fungal succession, blue-stain fungi.


2007 ◽  
Vol 85 (3) ◽  
pp. 307-315 ◽  
Author(s):  
Adrianne V. Rice ◽  
Markus N. Thormann ◽  
David W. Langor

Mountain pine beetles ( Dendroctonus ponderosae Hopkins; (MPB)) have spread into lodgepole × jack pine hybrid ( Pinus contorta Douglas × Pinus banksiana Lambert) forests in Alberta and are predicted to spread into jack pine forests. Their success in these forests is uncertain but will be influenced by multiple factors, including the ability of their associated blue-stain fungi to colonize the trees and the health of the encountered trees. Healthy and dwarf mistletoe infected pines at three sites across Alberta (one site per pine species) were inoculated with three isolates each of Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield and Ophiostoma montium (Rumbold) von Arx. Both fungi grew and caused lesions on all hosts, suggesting that MPB will not be limited by a lack of fungal growth. Both fungi caused longer lesions in jack and hybrid pines than in lodgepole pines, indicating that susceptibility varies among hosts and is greater in the novel systems than in the co-evolved one. G. clavigera caused longer lesions than O. montium in hybrids and lodgepole pines, while the two species caused similar-sized lesions on jack pine. Intraspecific variation was high in G. clavigera, with one isolate producing much shorter lesions than the other two. Dwarf mistletoe infestation had little effect on infection lesion length.


1962 ◽  
Vol 40 (4) ◽  
pp. 609-614 ◽  
Author(s):  
Robena C. Robinson

A complex of fungi was isolated from lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) at various stages of mountain pine beetle (Dendroctonus monticolae Hopk.) attack. Ceratocystis montia Rumb., Leptographium sp., Pichia pini (Hoist) Phaff, Hansenula holstii Wickerham, Hansenula capsulata Wickerham, and some unnamed yeasts were isolated from beetles, fresh galleries, and blue-stained sapwood. Perithecia of C. montia, Ceratocystis minor (Hedgc.) Hunt, Ceratocystis minuta (Siem.) Hunt, Ceratocystis sp., and Europhium sp. were found on the bark and sapwood of dead, blue-stained trees. Beetles are conclusively shown to be vectors of blue stain fungi. The known ranges of C. montia and P. pini are extended by this study and a possible succession of organisms associated with the development of beetle infestation is discussed.


1961 ◽  
Vol 37 (4) ◽  
pp. 368-375 ◽  
Author(s):  
R. W. Reid

The moisture content of the outer sapwood of non-infested lodgepole pine is normally about 85 to 165 per cent of oven dry weight. In trees that have been infested by the mountain pine beetle for one year, the sapwood moisture content can be as low as 16 per cent. There is a steep moisture gradient from about 160 per cent in the outer sapwood to about 30 per cent in the heart-wood. The moisture content in the centre is slightly higher than in the adjacent wood. In infested trees the sapwood moisture is greatly reduced within a year after the attack but moisture in the heartwood is not altered appreciably. Trees infested early in the season drop to a lower moisture content by fall than trees infested later in the season. In non-infested trees there is a diurnal and a seasonal moisture march; these do not occur in infested trees. The rapid moisture loss in the sapwood of infested trees is associated with blue-stain infection and successful establishment of bark-beetle broods


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