Seasonal and Long-Term Responses of Host Trees to Microbial Associates of the Pine Engraver, Ips pini

1988

5 Abb., 8 Tab., 32 Lit. Ang.

Unselbständiges Werk

9716

200038794

Within-season responses of Pinus resinosa and Pinus banksiana to fungi vectored by the pine engraver, Ips pini,are strongly influenced by the month of inoculation. The seasonal pattern is a characteristic of the host-fungus interaction, rather than being indicative of either ost- or fungal-specific proporties alone. The most consistent trend was that early season inoculation resulted in more raped lesion formation in sapwood than in phloem and thatthis difference declined as the growing season progressed. Prior inoculation h ad no effect on necrotic lesion formation. Inoculated trees were examined for three growing seasons. No significant damage related to treatment occurred to either P. resinosa or P. banksiana during this interval. However, Ceratocystis ips persisted in living hosts for a longer period than did Ceratocystis nigrocarpa and showed signs of radial and vertical progression throughout the first and beginning of the second growing season. This was especially true in P. resinosa, the host in which the short-term studies revealed the lower lesion growthrate. There was no lesion formation during the third season. Inoculated fungi could be reisolated from within but not outside the resulting lesion.