The distribution and estimation of jack pine budworm defoliation

1992 ◽  
Vol 22 (8) ◽  
pp. 1079-1088 ◽  
Author(s):  
W. Jan A. Volney

A method to categorize defoliation on current year's shoots of jack pine (Pinusbanksiana Lamb.) was developed. The pattern of defoliation caused by the jack pine budworm (Choristoneurapinuspinus Free.) feeding on jack pine trees was studied in a variety of locations in Manitoba and Saskatchewan over several years. In addition to differences among locations and years, the crown level from which a sample was taken, the branch within a tree, the tree within a plot, and the plot within a study location were consistent sources of variation. In general, the upper crown was most heavily defoliated and the lower crown least so. Branches, trees, and plots are random sources of variation, and the variance components associated with each such source were analyzed to determine their contribution to the overall variance in the estimate of defoliation. The relative importance of each random source of variation varied with the percent defoliation. Variation among plots was significant at defoliation levels below 45% and peaked at 25%, indicating a patchy distribution of feeding within stands in this range of defoliation. Beyond 45% defoliation, feeding was uniformly distributed among plots within a stand. Variation in defoliation among branches and trees peaked in the 50–60% defoliation range and was negligible at the extremes. Advantage can be taken of the consistent patterns of defoliation among crown levels and knowledge of the variance components of the random sources of variation to design defoliation assessment protocols. These data were used to optimize the allocation of effort, among plots, trees, and branches, required to determine the level of defoliation in stands either with fixed level of effort or to a specified level of precision.

1999 ◽  
Vol 29 (10) ◽  
pp. 1510-1517 ◽  
Author(s):  
Bradley E Conway ◽  
Deborah G McCullough ◽  
Larry A Leefers

Growth of jack pine (Pinus banksiana Lamb.) trees from the Raco Plains area in the Upper Peninsula of Michigan was examined over an 18-year period (1978-1995) that included two jack pine budworm (Choristoneura pinus pinus Freeman) outbreaks. Specific volume increments were calculated for 84 trees grouped into three classes based on their status in 1996; 36 trees were undamaged, 24 trees had been recently top-killed, and 24 trees had been recently killed. Average growth was converted to proportion of previous years' growth for three periods: before the 1983-1985 outbreak, between the 1983-1985 and 1991-1993 outbreak, and after the onset of the 1991-1993 outbreak. Differences in growth over these periods among undamaged, recently top-killed, and recently killed trees were evaluated. Growth did not differ among the three groups before the 1983-1985 outbreak. From 1983-1990, undamaged and recently top-killed trees grew significantly more than recently killed trees. There was no difference in average growth from 1983 to 1990 between undamaged and recently top-killed trees. Growth of undamaged trees was significantly greater than growth of recently top-killed trees following the onset of defoliation from the 1991-1993 outbreak. Patterns of growth loss suggest that a history of defoliation stress from multiple budworm outbreaks was an important determinant of tree mortality.


1950 ◽  
Vol 82 (2) ◽  
pp. 34-43 ◽  
Author(s):  
R. R. Lejeune

The jack-pine budworm, Ohoristoneura sp., was first recorded by Graham (5, 6) as a new variety or race on jack pine. Subsequent studies by Graham (6 showed that in the early stages of their development the larvae of this insect prefer jack-pine staminate flowers as a habitat. Population records from Manitoba and northwestern Ontario indicate that infestations of the jack-pine budworm are invariably associated with an abundance of staminate flowers.


1987 ◽  
Vol 17 (1) ◽  
pp. 51-57 ◽  
Author(s):  
P. J. Bedker ◽  
M. J. Wingfield ◽  
R. A. Blanchette

Three species of 11-year-old pine trees were inoculated with Bursaphelenchusxylophilus in the field. Four branches in single whorls on red, Scots, and jack pine trees were wounded and inoculated with 10 000 nematodes each or with water extracts from Botrytiscinerea cultures. Prior to field inoculations, the pathogenicity of the nematode isolate was confirmed on seedlings in the greenhouse. Fourteen weeks after inoculation, 27 of 80 and 13 of 52 branches were dead or dying on Scots and jack pine trees, respectively. No symptoms were observed on red pine trees inoculated with B. xylophilus or on any controls. Branch death was attributed to the formation of girdling cankers resulting from inoculation. An average of 9.14, 10.39, and 0.02 nematodes were extracted per gram of wood from branch samples collected from Scots, jack, and red pine trees at 14 weeks, respectively, and at 58 weeks an average of 13.82, 1.01, and 0.05 nematodes per gram of wood sampled were recovered. Proportions of branch samples with nematodes declined from 14 to 58 weeks after inoculation. Although limited mortality of branches occurred, the pine wood nematode was not found to cause tree death following inoculation.


2004 ◽  
Vol 118 (4) ◽  
pp. 595 ◽  
Author(s):  
Brock Epp ◽  
Jacques C. Tardif

The Lodgepole Pine Dwarf Mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is an important pathogen of Jack Pine (Pinus banksiana Lamb.). Dwarf Mistletoe alters tree form, suppresses growth, and reduces volume and overall wood quality of its host. Stem analysis and a 3-parameter logistic regression model were used to compare the growth of heavily and lightly to non infected Jack Pine trees. At the time of sampling, no significant reduction in diameter at breast height and basal area were observed in heavily infected trees. However, a significant reduction in height and volume and an increase in taper were observed in heavily infected trees. Growth models predicted a 21.1% lower basal area, 23.4% lower height and 42.1% lower volume by age 60 for the high infection group.


1974 ◽  
Vol 52 (7) ◽  
pp. 817-821
Author(s):  
Gary A. Simmons ◽  
Norman F. Sloan

Predation by the eastern chipping sparrow, Spizella passerina (Bechstein), on the jack-pine budworm, Choristoneura pinus Freeman, was investigated in northern Michigan. Singing-male counts and bird-banding records provided estimates of bird populations, budworm consumption rates were estimated from observation cage results, and budworm populations were estimated from branch sample counts. Average rate of consumption of all life forms of the budworm was 7.8/h per bird and remained nearly the same regardless of the number of life stages of the budworm available. Overall consumption was 3000/acre (7500/ha) for adults, 600/acre (1500/ha) for juveniles, and 300/acre (750/ha) for nestlings over a 22-day feeding period, resulting in 0.92% budworm mortality. Methods of estimating juvenile and nestling consumption of budworm are presented.


1996 ◽  
Vol 26 (12) ◽  
pp. 2180-2190 ◽  
Author(s):  
Deborah G. McCullough ◽  
Lyle J. Buss ◽  
Larry D. Marshall ◽  
Jari Kouki

Stand-level mortality and top kill from a 1991–1993 jack pine budworm (Choristoneurapinuspinus Freeman) outbreak were surveyed annually in the Raco Plains area of the Hiawatha National Forest in Michigan's Upper Peninsula from 1992 to 1994. Defoliation was visually estimated and percentage of trees killed or top killed was determined in 104 stands. In 1994, tree mortality attributable to the outbreak averaged 8% and 17% of trees had dead tops. Current stand inventory data, including age, site index, basal area, and size, were acquired from the Hiawatha Forest. Stands were grouped on the basis of inventory variables used for jack pine management in the Lake States region of the United States. Differences in tree mortality and top kill between groups, and associations between tree mortality and inventory variables, were evaluated. Tree mortality was greater in overmature stands and in overstocked stands, but stand size had little effect. Contrary to expectations, mortality was lower on poor sites with low site index values than on better sites with higher site index values. Mortality was not related to abundance of open-grown, full-canopied wolf trees or to abundance of trees infected with pine gall rust (Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka (=Peridermiumharknessii J.P. Moore)). Amount of top kill was related to defoliation severity and was higher in overmature and understocked stands. Top kill was not strongly associated with amount of tree mortality or with inventory variables.


1989 ◽  
Vol 67 (5) ◽  
pp. 1318-1323 ◽  
Author(s):  
Duncan G. L. Innes ◽  
James F. Bendell

In late June 1985, both operational and experimental aerial spraying was conducted against an outbreak of jack pine budworm (Choristoneura pinus) in northern Ontario. We report the effects of the insecticides Bacillus thuringiensis, fenitrothion, and Matacil® on populations of rodents and shrews in young (20 years) and medium-aged (40 years) jack pine (Pinus banksiana) plantations. Live, snap, and pitfall traps were used to monitor small-mammal populations from early June to late August on four sprayed plots and two control plots. We found no statistically significant differences in abundances that could be attributed to an insecticide. However, pitfall trapping suggested that the abundance of shrews was altered by the fenitrothion spray. Both the pattern and magnitude of shrew captures was different relative to a control and two other treatment plots. This difference may have resulted from the lack of available prey (arthropods) on the fenitrothion plot. With the exception of fenitrothion, our results agree with other studies which suggest that standard applications of insecticides to control forest insects have no detectable or only limited impact on small mammals.


Sign in / Sign up

Export Citation Format

Share Document