Forecasting the response of spruce budworm defoliation to climate change in Ontario

2011 ◽  
Vol 41 (10) ◽  
pp. 1948-1960 ◽  
Author(s):  
Jean-Noël Candau ◽  
Richard A. Fleming

Predicting the effect of climate change on insect populations is critical to improve the reliability of forest management plans, wood supply projections, and pest protection programs. In this study, we use an empirical model to relate the spatial distribution of past defoliation by spruce budworm ( Choristoneura fumiferana Clem.) in Ontario to bioclimatic variables. We then apply data from six climate change scenarios to this model to project potential changes in the distribution of defoliation for 2011–2040. The spatial distribution of historical defoliation was found to be related to winter maximum and minimum temperatures, forest content in balsam fir ( Abies balsamea (L.) Mill.) and white spruce ( Picea glauca (Moench) Voss), and spring and summer minimum temperatures. All six climate change scenarios project broadly similar changes in the spatial patterns of defoliation: (i) an extension of the northern limit of defoliation as far as available data go or close to it, (ii) a decrease in the frequency of defoliation in the center of the historical defoliation belt, and (iii) a persistence of the southern limit of defoliation. This leads to a projected increase of the total area defoliated of between 22.8% and 25.5%, while the mean frequency of defoliation, calculated over the whole study area, would slightly increase (+1%) or decrease (–17.7% to –2.9%).

1971 ◽  
Vol 49 (7) ◽  
pp. 1005-1011 ◽  
Author(s):  
J. P. Kimmins

The amino acids of new and old foliage of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) were investigated using two-dimensional descending paper chromatography. The data were analyzed for variation associated with age of foliage, age of tree, and flowering condition. The concentration of foliar amino acids was greater in balsam fir than in white spruce, and greater in new foliage than old foliage.The difference in concentration between foliage of flowering and non-flowering trees was smaller. However, the new foliage of flowering fir had higher levels of most of the amino acids examined than any other foliage category. This appears to reflect the known suitability of these foliage categories for spruce budworm larvae. While the data presented do not quantify the ecological significance of this apparent correlation, they do support the theory that variations in the nutritional quality of host plants play a very important role in the dynamics of herbivore populations.


1958 ◽  
Vol 34 (1) ◽  
pp. 39-47 ◽  
Author(s):  
J. R. Blais

The relationship between spruce budworm defoliation and radial growth at breast height for balsam fir and white spruce trees of merchantable size was studied in various stands in northwestern Ontario. Defoliation was recorded yearly for these stands from the beginning of the infestation, and radial growth measurements were obtained from increment cores. The first year of radial growth suppression was calculated by comparing the growth of the affected species with that of jack pine and red pine trees by means of a growth-ratio technique. Apparent suppression in balsam fir and white spruce varied between stands, and, generally, occurred at the earliest in the second year and at the latest in the fourth year of severe defoliation. A wide ring at the base of the tree coinciding with the first year of suppression as reported by Craighead was non-existent.


1975 ◽  
Vol 107 (7) ◽  
pp. 717-728 ◽  
Author(s):  
G. T. Harvey

AbstractAmylopectin added to a sugar-free wheat-germ diet was equal to or better than sucrose as a carbohydrate source, and appears to be readily utilized by the eastern spruce budworm (Choristoneura fumiferana (Clem.)). Larval growth on diets containing dextrins or potato starch shows that they are partly utilized. Starches from other sources, including those isolated from mature balsam fir (Abies balsamea (L.) Mill.) or white spruce (Picea glauca (Moench) Voss) needles, are not utilized to any extent, on the basis of larval growth on diets to which they have been added.Sixth-instar budworm reared on artificial diets contain amylase(s) in midgut and salivary gland homogenates, which show a low rate of digestion of starches from host foliage. However, the presence of appreciable starch in frass from foliage-fed insects and the apparent low utilizability of foliar starch indicate that the latter is not an important nutrient for the budworm under natural conditions.


2006 ◽  
Vol 138 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Gary G. Grant

AbstractI conducted dual-choice oviposition bioassays to test the hypothesis that spruce budworm, Choristoneura fumiferana (Clemens), prefer the foliage architecture (spatial arrangement of foliage needles) of white spruce (Picea glauca (Moench) Voss; Pinaceae) to that of balsam fir (Abies balsamea (L.) P. Mill.; Pinaceae). Needles of white spruce radiate around the twig axis, giving the foliage a round architecture. Needles of balsam fir typically radiate bilaterally from the twig axis, giving the foliage a flat architecture, although on some trees foliage needles radiate around the twig axis, giving the foliage a round architecture. In bioassays, females showed a 2.4:1 preference for white spruce over "flat" balsam fir foliage, but this preference was reduced significantly to a 1.2:1 ratio when balsam fir had a round architecture. Given a choice between "round" and "flat" balsam fir foliage, females preferred the "round" foliage by a 2.2:1 margin. A similar preference for the round architecture was also observed when artificial (plastic) foliage with the two types of needle arrangements were compared. I conclude that the spatial arrangement of foliage needles is a major factor responsible for the oviposition preference of spruce budworm for white spruce over balsam fir.


2011 ◽  
Vol 102 (3) ◽  
pp. 275-284 ◽  
Author(s):  
A. Fuentealba ◽  
É. Bauce

AbstractThe effect of host nutritional quality on spruce budworm (Choristoneura fumiferana (Clemens)) parental and offspring performance was studied using field and laboratory rearing experiments, and foliar chemical analyses. Foliage of balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca (Moench) Voss) and black spruce (P. mariana (Mill.) BSP) was used to rear the parental generation in the field, whereas an artificial diet was used to rear the progeny under laboratory conditions. Important differences in the food quality were provided by the three hosts. Black spruce foliage had higher concentrations of certain monoterpene deterrents and total phenolics, together with stronger seasonal declines in nutrients such as N, P and Mg, compared with the other hosts. We hypothesise that this trend may be related to poor performance and survival of the progeny. Laboratory rearing showed that progeny of parents that fed on black spruce exhibited longer developmental times and greater mortality, and had lower pupal mass than progeny of parents fed on the other hosts. Further, artificial food-fed progeny of insects reared on black spruce reached sixth-instar later, with lower mass, and exhibited higher relative growth rate (RGR) than progeny of parents fed on the other hosts. These results suggest nutritionally-based parental effects. These results also confirmed that the quality of food consumed by the parents can influence the fitness of the next generation.


1984 ◽  
Vol 116 (1) ◽  
pp. 101-102 ◽  
Author(s):  
O. N. Morris

Bacillus thuringiensis var. kurstaki (B.t.) is the most widely used biological control agent against the spruce budworm, Choristoneura fumiferana (Clem.), a major defoliator of coniferous forests. The technology of applying the bacterium, however, is still not fully developed and the strategy of applying single or split applications of B.t. in unmixed stands is still in question. Double applications are generally accepted as necessary in mixed stands of white spruce, Picea glauca (Moench) Voss, red spruce, P. rubens Sarg., black spruce, P. mariana (Mill.) BSP, and balsam fir, Abies balsamea (L.) Mill., due to difference in the phenological development of the host trees and of the budworm infesting them. Field trials were conducted at Mine Centre, Ontario, to compare the efficacies of double and single applications of B.t. against the budwonn infesting balsam fir stands.


2020 ◽  
Vol 50 (6) ◽  
pp. 565-580
Author(s):  
Yuanyuan Wu ◽  
David A. MacLean ◽  
Chris Hennigar ◽  
Anthony R. Taylor

Defoliation level and site type are thought to influence tree response during spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks. We determined the effects of four manual defoliation treatments (0%, 50%, 100%, and 100% + bud removal of current foliage) for 3 years on foliage production of balsam fir (Abies balsamea (L.) Mill.), black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.), and white spruce (Picea glauca (Moench) Voss) trees on four site-quality classes. After 3 years of defoliation and 2 years of recovery, foliage biomass was reduced by 34%–98%. During defoliation, the number of shoots generally increased and shoot length of spruce generally decreased, especially on rich sites. During recovery, the number of shoots increased substantially, shoot length decreased, and bud destruction reduced the number of shoots by about 50% compared with that of trees that received the 100% defoliation treatment. Defoliation did not substantially affect needle length. Trees on rich sites had two- to fourfold greater foliage production than trees on poor sites. Effects of site and defoliation differed among species, but site quality, especially nutrition, played an important role in production of shoots and needles and the tree’s ability to withstand defoliation. Black spruce had more limited ability to recover foliage biomass, only producing more shoots, whereas balsam fir and white spruce had stronger ability to recover needle and shoot length, respectively.


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 720
Author(s):  
Jacques Régnière ◽  
Lisa Venier ◽  
Dan Welsh

The impact of avian predation on a declining population of the spruce budworm, Choristoneura fumifereana (Clem.), was measured using single-tree exclosure cages in a mature stand of balsam fir, Abies balsamea (L.), and white spruce, Picea glauca (Moench.) Voss. Bird population censuses and observations of foraging and nest-feeding activity were also made to determine the response of budworm-linked warblers to decreasing food availability. Seasonal patterns of foraging. as well as foraging success in the declining prey population was compared to similar information from birds observed in another stand where the spruce budworm population was rising. Avian predation was an important source of mortality between the 4th instar and moth emergence in the declining outbreak population. Mortality by predation increased from negligible to over 98% as budworm density dropped from 100 to <1 larva/kg of host foliage, over 3 years. Calculations based on nest-feeding activity and basic metabolic demands support these observed rates. Seasonal and yearly differences in predation rates observed between the two host-tree species correspond to equivalent shifts in bird foraging behavior in response to dropping insect density. In particular, a preference for searching on white spruce disappeared, although budworm-linked birds remained more efficient at finding food on this plant. The ability to change foraging behavior as prey density dropped differed between bird species.


2004 ◽  
Vol 34 (11) ◽  
pp. 2351-2362 ◽  
Author(s):  
Wayne E MacKinnon ◽  
David A MacLean

The species composition of surrounding forest and site characteristics have been postulated to influence growth loss caused by eastern spruce budworm (Choristoneura fumiferana Clem.) defoliation. Forty spruce (Picea spp.) and balsam fir (Abies balsamea (L.) Mill.) stands located in north-central New Brunswick, Canada, were measured for defoliation and tree growth and used to determine the effects of surrounding forest (softwood, mixedwood), site (wet soil – nutrient poor; moist soil – nutrient rich), and species group (balsam fir, spruce) on growth reduction caused by spruce budworm. Stem analysis of six trees per stand (total 240 trees) determined mean specific volume increment (SVI) per year in 1973–1993. There was relatively little defoliation during the 1989–1993 measurement period, and regression analyses showed that SVI was significantly (p = 0.0299) related to mean defoliation for only one of eight treatment classes: balsam fir on moist–rich sites in mixedwood forests. However, two periods of earlier growth reduction were evident, and analysis of variance showed that balsam fir on wet–poor sites sustained 12% greater (p = 0.0071) reduction in SVI from 1987 to 1990 than balsam fir on moist–rich sites. White spruce (Picea glauca (Moench) Voss) sustained 13% greater (p = 0.0198) reduction in SVI from 1973 to 1978 than red spruce (Picea rubens Sarg.) – black spruce (Picea mariana (Mill.) BSP). Surrounding forest type did not significantly affect SVI reduction from 1973 to 1978 or from 1987 to 1990, but from 1973 to 1978 stands in softwood forest sustained 5%–8% more growth reduction than those in mixedwood forest.


1984 ◽  
Vol 116 (2) ◽  
pp. 153-158 ◽  
Author(s):  
R. C. Reardon ◽  
K. Haissig

AbstractBacillus thuringiensis was applied at three dosages (1.0 BIU/tree, 0.1 BIU/tree, and.01 BIU/tree) to balsam fir, Abies balsamea (L.) Mill., and white spruce, Picea glauca (Moench) Voss, with mist blowers. Crystalline proteins were detected on balsam fir foliage for a maximum of 16 days (d) after B. thuringiensis was applied at 1.0 BIU/tree. Higher levels of crystalline proteins were detected on white spruce foliage treated with Thuricide 16B than on that treated with Dipel 4L. On balsam fir, the situation was the opposite. Mist-blower-treated foliage collected for up to 16 d posttreatment caused mortality of spruce budworm, Choristoneura fumiferana (Clemens), larvae. Viable endospores of B. thuringiensis were recovered on white spruce foliage collected 1 year after treatment.


Sign in / Sign up

Export Citation Format

Share Document