Taste receptor activity and feeding behaviour reveal mechanisms of white spruce natural resistance to Eastern spruce budworm Choristoneura fumiferana

White spruce (Picea glauca (Moench) Voss) plantations have historically been an important source of high-quality forest products in the Great Lakes Region of North America. Thinning in spruce plantations is a common silvicultural practice for reducing competition and promoting resiliency to forest health threats such as eastern spruce budworm (Choristoneura fumiferana Clemens), a native forest pest of eastern North America. Spruce budworm larvae feed on the foliage of trees, which reduces growth and potentially causes mortality during an outbreak. There has been continual spruce budworm defoliation in northern Minnesota, U.S.A., since the mid-1950s, with higher levels of defoliation in the late 1990s. This research modeled the diameter growth response of white spruce 18 years after initial thinning in stands that presently range between 44 and 64 years old. Some stands received a second thinning in recent years. We used generalized nonlinear least squares and nonlinear mixed-effects models to estimate annual diameter growth using common tree and stand metrics. Growth model performance was improved by including thinning and frequency of spruce budworm defoliation as modifiers of diameter growth. Results of this study highlight how thinning in combination with insect disturbance affect diameter growth in white spruce plantations of northern Minnesota.

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An endophytic fungus interacts with crown level and larval density to reduce the survival of eastern spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae), on white spruce (Picea glauca)

Canadian Journal of Forest Research ◽

10.1139/cjfr-2018-0194 ◽

2019 ◽

Vol 49 (3) ◽

pp. 221-227 ◽

Cited By ~ 9

Author(s):

Dan Quiring ◽

Leah Flaherty ◽

Greg Adams ◽

Andrew McCartney ◽

J. David Miller ◽

...

Keyword(s):

Endophytic Fungus ◽

Picea Glauca ◽

Significant Interaction ◽

Choristoneura Fumiferana ◽

Larval Density ◽

Spruce Budworm ◽

White Spruce ◽

Larval Survival ◽

Total Survival ◽

Eastern Spruce Budworm

A two-year field study was carried out to determine whether inoculating white spruce, Picea glauca (Moench) Voss, with a native endophytic fungus, Phialocephala scopiformis DAOM 229536 Kowalski & Kehr (Helotiales, Ascomycota), decreased the performance of eastern spruce budworm, Choristoneura fumiferana Clemens, developing on these trees. Second instars were reared at three densities in the mid crown and at one density in the lower, mid, and upper crown. Larval survival (i.e., survival of larvae to pupation) was lower on endophyte-inoculated trees than on control trees in the mid crown and especially the upper crown but was similar in the lower crown, resulting in a significant interaction between endophyte and crown level. A similar but marginally insignificant interaction was observed for overall survival up to adult emergence (i.e., total survival). Larval survival and total survival were approximately 22% and 19% lower, respectively, when developing in the upper crown of endophyte-inoculated trees than in control trees. Larval survival remained relatively constant, with increased density on control trees but decreased with density on endophyte-inoculated trees, resulting in a significant interaction between endophyte and larval density. Sex ratios of emerged adults and wing lengths of emerged females were not influenced by the endophyte. Our results suggest that endophytic fungi could be useful additions to integrated pest management programs.

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A Foliar Endophyte of White Spruce Reduces Survival of the Eastern Spruce Budworm and Tree Defoliation

Forests ◽

10.3390/f11060659 ◽

2020 ◽

Vol 11 (6) ◽

pp. 659 ◽

Cited By ~ 1

Author(s):

Dan Quiring ◽

Greg Adams ◽

Andrew McCartney ◽

Sara Edwards ◽

J. David Miller

Keyword(s):

Endophytic Fungus ◽

Picea Glauca ◽

Integrated Management ◽

Choristoneura Fumiferana ◽

Adult Emergence ◽

Spruce Budworm ◽

White Spruce ◽

Tree Defoliation ◽

Eastern Spruce Budworm

Wild eastern spruce budworm (Choristoneura fumiferana Clemens) were reared on white spruce (Picea glauca (Moench) Voss) trees, half of which had been previously inoculated with a native endophytic fungus, Phialocephala scopiformis DAOM 229536 Kowalski and Kehr (Helotiales, Ascomycota). Survival up to pupation and up to adult emergence was approximately 27% higher for budworm juveniles that developed on control trees compared to trees inoculated with the endophyte. The endophyte did not influence the size or sex of survivors but did reduce defoliation by approximately 30%. Reductions in defoliation on endophyte-inoculated versus control trees, due to reductions in survival of juvenile budworms, suggests that tree inoculations with P. scopiformis could play an important role in integrated management programs against the eastern spruce budworm.

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Observations on the feeding behaviour of late-instar larvae of Choristoneura fumiferana

The Canadian Entomologist ◽

10.4039/n10-031 ◽

2010 ◽

Vol 142 (4) ◽

pp. 388-392 ◽

Cited By ~ 4

Author(s):

Kees van Frankenhuyzen ◽

Sylvain Espinasse

Keyword(s):

Bacillus Thuringiensis ◽

Feeding Behaviour ◽

Choristoneura Fumiferana ◽

Spruce Budworm ◽

Eastern Spruce Budworm ◽

Late Instar ◽

Feeding Bout ◽

Subsequent Interval ◽

Observation Period

AbstractLaboratory observations revealed that late-instar larvae of the eastern spruce budworm (Choristoneura fumiferana (Clemens)) (Lepidoptera: Tortricidae) spend most of their time spinning, wandering, and resting; less than 10% is spent feeding. Larvae feed in a discontinuous pattern of short feeding bouts separated by much longer intervals of nonfeeding activity. Over a 2 h observation period, feeding bouts averaged 2.2 min and were separated by 17.4 min intervals for 4th-instar larvae as compared to 3.3 min bouts separated by 33.4 min intervals for 5th-instar larvae. The duration of a feeding bout was positively correlated with the duration of the subsequent interval, not with the duration of preceding intervals, suggesting that feeding-bout frequency is governed primarily by post-ingestion processes. It is postulated that short feeding bouts followed by long intervals limit the window for ingesting an efficacious dose of aerially applied insecticides such as Bacillus thuringiensis.

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Influence of a Foliar Endophyte and Budburst Phenology on Survival of Wild and Laboratory-Reared Eastern Spruce Budworm, Choristoneura fumiferana on White Spruce (Picea glauca)

Forests ◽

10.3390/f10060503 ◽

2019 ◽

Vol 10 (6) ◽

pp. 503 ◽

Cited By ~ 2

Author(s):

Dan Quiring ◽

Greg Adams ◽

Leah Flaherty ◽

Andrew McCartney ◽

J. David Miller ◽

...

Keyword(s):

Field Study ◽

Wild Population ◽

Choristoneura Fumiferana ◽

Insect Pest ◽

Intervention Strategy ◽

Adult Emergence ◽

Spruce Budworm ◽

White Spruce ◽

Eastern Spruce Budworm ◽

Laboratory Colony

A manipulative field study was carried out to determine whether the foliar endophyte fungus, Phialocephala scopiformis DAOM 229536, decreased the performance of eastern spruce budworm, Choristoneura fumiferana larvae developing on white spruce trees. Overwintered second-instar budworm larvae from a laboratory colony or from a wild population were placed on endophyte positive or negative trees one or two weeks before budburst. The presence of the endophyte in the needles reduced the survival of C. fumiferana from both a wild population and a laboratory colony. Survival for budworm juveniles up to pupation and to adult emergence was 13% and 17% lower, respectively, on endophyte positive trees. The endophyte did not influence the size or sex of survivors and budworm survival was not influenced by any two- or three-way interactions. Budworm survival was higher for wild than for laboratory-reared budworm and for budworm placed on trees a week before budburst. This may be the first field study to demonstrate the efficacy of an endophytic fungus against wild individuals of a major forest insect pest. The efficacy of the endophyte at low larval densities suggests that it could be a useful tactic to limit spruce budworm population growth in the context of an early intervention strategy.

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WHITE SPRUCE AND THE SPRUCE BUDWORM: DEFINING THE PHENOLOGICAL WINDOW OF SUSCEPTIBILITY

The Canadian Entomologist ◽

10.4039/ent129291-2 ◽

1997 ◽

Vol 129 (2) ◽

pp. 291-318 ◽

Cited By ~ 79

Author(s):

Robert K. Lawrence ◽

William J. Mattson ◽

Robert A. Haack

Keyword(s):

Picea Glauca ◽

High Performance ◽

Choristoneura Fumiferana ◽

Spruce Budworm ◽

White Spruce ◽

Shoot Elongation ◽

Larval Survival ◽

Strongly Correlated ◽

Negative Effect ◽

Foliar Traits

AbstractSynchrony of insect and host tree phenologies has often been suggested as an important factor influencing the susceptibility of white spruce, Picea glauca (Moench) Voss, and other hosts to the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). We evaluated this hypothesis by caging several cohorts of spruce budworm larvae on three white spruce populations at different phenological stages of the host trees, and then comparing budworm performance with host phenology and variation of 13 foliar traits. The beginning of the phenological window of susceptibility in white spruce occurs several weeks prior to budbreak, and the end of the window is sharply defined by the end of shoot growth. Performance was high for the earliest budworm cohorts that we tested. These larvae began feeding 3–4 weeks prior to budbreak and completed their larval development prior to the end of shoot elongation. Optimal synchrony occurred when emergence preceded budbreak by about 2 weeks. Larval survival was greater than 60% for individuals starting development 1–3 weeks prior to budbreak, but decreased to less than 10% for those starting development 2 or more weeks after budbreak and thus completing development after shoot elongation ceased. High performance by the budworm was most strongly correlated with high levels of foliar nitrogen, phosphorous, potassium, copper, sugars, and water and low levels of foliar calcium, phenolics, and toughness. These results suggest that advancing the usual phenological window of white spruce (i.e. advancing budbreak prior to larval emergence) or retarding budworm phenology can have a large negative effect on the spruce budworm’s population dynamics.

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FACTORS AFFECTING ADULT EMERGENCE AND MATING BEHAVIOR OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

The Canadian Entomologist ◽

10.4039/ent107967-9 ◽

1975 ◽

Vol 107 (9) ◽

pp. 967-977 ◽

Cited By ~ 27

Author(s):

C. J. Sanders

Keyword(s):

Field Experiments ◽

Choristoneura Fumiferana ◽

Adult Emergence ◽

Spruce Budworm ◽

Field Conditions ◽

Continuous Illumination ◽

Degree Days ◽

Factors Affecting ◽

Eastern Spruce Budworm ◽

Duration Of Copulation

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.

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LONG TERM STUDY OF THE EFFECTIVENESS OF AERIAL APPLICATION OF BACILLUS THURINGIENSIS – ACEPHATE COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

The Canadian Entomologist ◽

10.4039/ent1091239-9 ◽

1977 ◽

Vol 109 (9) ◽

pp. 1239-1248 ◽

Cited By ~ 15

Author(s):

O. N. Morris

Keyword(s):

Bacillus Thuringiensis ◽

Choristoneura Fumiferana ◽

Larval Mortality ◽

Abies Balsamea ◽

Spruce Budworm ◽

White Spruce ◽

Balsam Fir ◽

Population Densities ◽

Long Term Study

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.

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A METHOD FOR REARING THE LARVAL STAGES OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEMENS (LEPIDOPTERA: TORTRICIDAE), FOR PHYSIOLOGICAL STUDIES

The Canadian Entomologist ◽

10.4039/ent1221271-11 ◽

1990 ◽

Vol 122 (6) ◽

pp. 1271-1272 ◽

Cited By ~ 3

Author(s):

Hemendra Mulye ◽

Roger Gordon

Keyword(s):

Population Dynamics ◽

North America ◽

Choristoneura Fumiferana ◽

Insect Pest ◽

Spruce Budworm ◽

Forest Pest ◽

Forest Insect ◽

Larval Stages ◽

Eastern Spruce Budworm ◽

Physiological Studies

The eastern spruce budworm, Choristoneura fumiferana Clemens, is the most widely distributed and destructive forest insect pest in North America. Although much is known about the ecology, population dynamics, and impact of C. fumiferana on tree growth (Sanders et al. 1985), there is very little information available on the physiology of this forest pest. Physiological studies are crucial to the development of novel strategies for spruce budworm control.

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