The Potential Role of Ectomycorrhizal Fungi in Determining Douglas-fir Resistance to Defoliation by the Western Spruce Budworm (Lepidoptera

Tortricidae)

Barbara L. Palermo, Karen M. Clancy, George W Koch

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

There is phenotypic variation among individual trees of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) in their resistance to defoliation by the western spruce budworm (Choristoneura occidentalis Freeman). We evaluated the potential role of ectomycorrhizal fungi in determining this resistance using half-sib seedlings derived from parent trees that are resistant versus susceptible to budworm defoliation in the field. The seedlings were inoculated with Laccaria bicolor ectomycorrhizal fungi, fertilized, or untreated. Approximately 48 d after treatment, late-instar larvae from a nondiapausing laboratory colony of C. occidentalis were allowed to feed on pairs of resistant versus susceptible seedlings for 1 wk. Chemical analyses of current-year shoots for nitrogen (N), phosphorus (P), magnesium (Mg), and zinc (Zn) indicated that the fungus increased foliar concentrations of P and Mg in resistant seedlings, but it did not increase their growth rate. However, L. bicolor had no effect on foliar concentrations of P or Mg in susceptible seedlings, even though seedling growth rates increased slightly in response to the inoculation. L. bicolor had no effect on foliar levels of N or Zn in any of the seedlings. As expected, fertilization increased levels of N and P in the foliage of both resistant and susceptible seedlings, but it did not affect levels of Mg and Zn. Surprisingly, the fertilizer treatment had no effect on seedling growth rates. Despite these differences, late-instar budworms showed no feeding preference among untreated, mycorrhizal, or fertilized seedlings. The fact that seedlings from resistant versus susceptible Douglas-firs responded differently to the L. bicolor treatment lends preliminary support to the hypothesis that ecotmycorrhizae might play a role in Douglas-fir resistance to damage from the western spruce budworm. Finally, differences in foliar concentrations of N and P among untreated seedlings from different maternal trees suggested that foliar nutritional chemistry is influenced by the tree's genotype.

Original languageEnglish (US)
Pages (from-to)783-791
Number of pages9
JournalJournal of Economic Entomology
Volume96
Issue number3
StatePublished - Jun 2003

Fingerprint

Choristoneura occidentalis
Tortricidae
defoliation
Pseudotsuga menziesii
Lepidoptera
seedling
fungus
fungi
seedlings
Laccaria bicolor
magnesium
zinc
seedling growth
instars
Pseudotsuga menziesii var. glauca
feeding preferences
phenotypic variation
individual variation
chemistry
fertilizer application

Keywords

  • Choristoneura occidentalis
  • Fertilization
  • Foliar nutrients
  • Laccaria bicolor
  • Larval feeding preferences
  • Minerals

ASJC Scopus subject areas

  • Insect Science

Cite this

The Potential Role of Ectomycorrhizal Fungi in Determining Douglas-fir Resistance to Defoliation by the Western Spruce Budworm (Lepidoptera : Tortricidae). / Palermo, Barbara L.; Clancy, Karen M.; Koch, George W.

In: Journal of Economic Entomology, Vol. 96, No. 3, 06.2003, p. 783-791.

Research output: Contribution to journalArticle

@article{712969821b384671854456367224c506,
title = "The Potential Role of Ectomycorrhizal Fungi in Determining Douglas-fir Resistance to Defoliation by the Western Spruce Budworm (Lepidoptera: Tortricidae)",
abstract = "There is phenotypic variation among individual trees of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) in their resistance to defoliation by the western spruce budworm (Choristoneura occidentalis Freeman). We evaluated the potential role of ectomycorrhizal fungi in determining this resistance using half-sib seedlings derived from parent trees that are resistant versus susceptible to budworm defoliation in the field. The seedlings were inoculated with Laccaria bicolor ectomycorrhizal fungi, fertilized, or untreated. Approximately 48 d after treatment, late-instar larvae from a nondiapausing laboratory colony of C. occidentalis were allowed to feed on pairs of resistant versus susceptible seedlings for 1 wk. Chemical analyses of current-year shoots for nitrogen (N), phosphorus (P), magnesium (Mg), and zinc (Zn) indicated that the fungus increased foliar concentrations of P and Mg in resistant seedlings, but it did not increase their growth rate. However, L. bicolor had no effect on foliar concentrations of P or Mg in susceptible seedlings, even though seedling growth rates increased slightly in response to the inoculation. L. bicolor had no effect on foliar levels of N or Zn in any of the seedlings. As expected, fertilization increased levels of N and P in the foliage of both resistant and susceptible seedlings, but it did not affect levels of Mg and Zn. Surprisingly, the fertilizer treatment had no effect on seedling growth rates. Despite these differences, late-instar budworms showed no feeding preference among untreated, mycorrhizal, or fertilized seedlings. The fact that seedlings from resistant versus susceptible Douglas-firs responded differently to the L. bicolor treatment lends preliminary support to the hypothesis that ecotmycorrhizae might play a role in Douglas-fir resistance to damage from the western spruce budworm. Finally, differences in foliar concentrations of N and P among untreated seedlings from different maternal trees suggested that foliar nutritional chemistry is influenced by the tree's genotype.",
keywords = "Choristoneura occidentalis, Fertilization, Foliar nutrients, Laccaria bicolor, Larval feeding preferences, Minerals",
author = "Palermo, {Barbara L.} and Clancy, {Karen M.} and Koch, {George W}",
year = "2003",
month = "6",
language = "English (US)",
volume = "96",
pages = "783--791",
journal = "Journal of Economic Entomology",
issn = "0022-0493",
publisher = "Entomological Society of America",
number = "3",

}

TY - JOUR

T1 - The Potential Role of Ectomycorrhizal Fungi in Determining Douglas-fir Resistance to Defoliation by the Western Spruce Budworm (Lepidoptera

T2 - Tortricidae)

AU - Palermo, Barbara L.

AU - Clancy, Karen M.

AU - Koch, George W

PY - 2003/6

Y1 - 2003/6

N2 - There is phenotypic variation among individual trees of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) in their resistance to defoliation by the western spruce budworm (Choristoneura occidentalis Freeman). We evaluated the potential role of ectomycorrhizal fungi in determining this resistance using half-sib seedlings derived from parent trees that are resistant versus susceptible to budworm defoliation in the field. The seedlings were inoculated with Laccaria bicolor ectomycorrhizal fungi, fertilized, or untreated. Approximately 48 d after treatment, late-instar larvae from a nondiapausing laboratory colony of C. occidentalis were allowed to feed on pairs of resistant versus susceptible seedlings for 1 wk. Chemical analyses of current-year shoots for nitrogen (N), phosphorus (P), magnesium (Mg), and zinc (Zn) indicated that the fungus increased foliar concentrations of P and Mg in resistant seedlings, but it did not increase their growth rate. However, L. bicolor had no effect on foliar concentrations of P or Mg in susceptible seedlings, even though seedling growth rates increased slightly in response to the inoculation. L. bicolor had no effect on foliar levels of N or Zn in any of the seedlings. As expected, fertilization increased levels of N and P in the foliage of both resistant and susceptible seedlings, but it did not affect levels of Mg and Zn. Surprisingly, the fertilizer treatment had no effect on seedling growth rates. Despite these differences, late-instar budworms showed no feeding preference among untreated, mycorrhizal, or fertilized seedlings. The fact that seedlings from resistant versus susceptible Douglas-firs responded differently to the L. bicolor treatment lends preliminary support to the hypothesis that ecotmycorrhizae might play a role in Douglas-fir resistance to damage from the western spruce budworm. Finally, differences in foliar concentrations of N and P among untreated seedlings from different maternal trees suggested that foliar nutritional chemistry is influenced by the tree's genotype.

AB - There is phenotypic variation among individual trees of interior Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) in their resistance to defoliation by the western spruce budworm (Choristoneura occidentalis Freeman). We evaluated the potential role of ectomycorrhizal fungi in determining this resistance using half-sib seedlings derived from parent trees that are resistant versus susceptible to budworm defoliation in the field. The seedlings were inoculated with Laccaria bicolor ectomycorrhizal fungi, fertilized, or untreated. Approximately 48 d after treatment, late-instar larvae from a nondiapausing laboratory colony of C. occidentalis were allowed to feed on pairs of resistant versus susceptible seedlings for 1 wk. Chemical analyses of current-year shoots for nitrogen (N), phosphorus (P), magnesium (Mg), and zinc (Zn) indicated that the fungus increased foliar concentrations of P and Mg in resistant seedlings, but it did not increase their growth rate. However, L. bicolor had no effect on foliar concentrations of P or Mg in susceptible seedlings, even though seedling growth rates increased slightly in response to the inoculation. L. bicolor had no effect on foliar levels of N or Zn in any of the seedlings. As expected, fertilization increased levels of N and P in the foliage of both resistant and susceptible seedlings, but it did not affect levels of Mg and Zn. Surprisingly, the fertilizer treatment had no effect on seedling growth rates. Despite these differences, late-instar budworms showed no feeding preference among untreated, mycorrhizal, or fertilized seedlings. The fact that seedlings from resistant versus susceptible Douglas-firs responded differently to the L. bicolor treatment lends preliminary support to the hypothesis that ecotmycorrhizae might play a role in Douglas-fir resistance to damage from the western spruce budworm. Finally, differences in foliar concentrations of N and P among untreated seedlings from different maternal trees suggested that foliar nutritional chemistry is influenced by the tree's genotype.

KW - Choristoneura occidentalis

KW - Fertilization

KW - Foliar nutrients

KW - Laccaria bicolor

KW - Larval feeding preferences

KW - Minerals

UR - http://www.scopus.com/inward/record.url?scp=0242407305&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0242407305&partnerID=8YFLogxK

M3 - Article

VL - 96

SP - 783

EP - 791

JO - Journal of Economic Entomology

JF - Journal of Economic Entomology

SN - 0022-0493

IS - 3

ER -