Jack pine budworm populations and staminate flowers

1990 ◽  
Vol 20 (8) ◽  
pp. 1253-1255 ◽  
Author(s):  
V. G. Nealis
Keyword(s):  
Population Dynamics ◽  
Relative Frequency ◽  
Larval Survival ◽  
Jack Pine ◽  
Northern Ontario ◽  
Feeding Sites ◽  
Jack Pine Budworm ◽  
Active Feeding ◽  
Early Instar ◽  
The Relationship

The relationship between jack pine budworm (Choristoneurapinuspinus Free.) and staminate flowers of its principal host, jack pine (Pinusbanksiana Lamb.), is reviewed. Data from jack pine budworm outbreaks in northern Ontario are used to examine the relationship between the relative frequency of staminate shoots and the mortality of early-and late-larval jack pine budworm. Although there was some indication that early-instar budworm may be more successful at establishing feeding sites when flowers are abundant, there was no evidence that larval survival during the active feeding stages of the budworm was enhanced by the presence of staminate flowers. The assumption that staminate flowers greatly influence jack pine budworm population dynamics is questioned.

The effects on small-mammal populations of aerial applications of Bacillus thuringiensis, fenitrothion, and Matacil® used against jack pine budworm in Ontario

1989 ◽  
Vol 67 (5) ◽  
pp. 1318-1323 ◽  
Author(s):  
Duncan G. L. Innes ◽  
James F. Bendell
Keyword(s):  
Bacillus Thuringiensis ◽  
Small Mammal ◽  
Pinus Banksiana ◽  
Jack Pine ◽  
Pitfall Traps ◽  
Pitfall Trapping ◽  
Northern Ontario ◽  
Limited Impact ◽  
Choristoneura Pinus ◽  
Jack Pine Budworm

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.

The Relationship of Spathimeigenia spinigera Townsend (Diptera: Tachinidae) to its Host, Neodiprion swainei Midd. (Hymenoptera: Diprionidae)

1962 ◽  
Vol 94 (8) ◽  
pp. 809-818 ◽  
Author(s):  
H. A. Tripp
Keyword(s):  
Population Dynamics ◽  
Pinus Banksiana ◽  
Jack Pine ◽  
Immature Stages ◽  
Pine Sawfly ◽  
Factors Influencing ◽  
Form Part ◽  
Extensive Program ◽  
Relationship Of ◽  
The Relationship

Studies on the parasites of the Swaine jack pine sawfly, Neodiprion swainei Midd., form part of an extensive program designed to assess the factors influencing population dynamics of this important defoliator of jack pine, Pinus banksiana Lamb. Investigations were carried out in the Province of Quebec between 1955 and 1959 near the headwaters of the Gatineau River, Abitibi County, and continued during 1960 and 1961 near the source of the Vermillion River, County Laviolette. In both areas, one of the principal parasites associated with N. swainei was the tachinid, Spathimeigenia spinigera Townsend. Descriptions of the immature stages of this parasite, and details of its behaviour were published previously (Tripp, 1960).

SAMPLING OVERWINTERING JACK PINE BUDWORM, CHORISTONEURA PINUS PINUS FREE. (LEPIDOPTERA: TORTRICIDAE), AND TWO OF ITS PARASITOIDS (HYMENOPTERA)

1988 ◽  
Vol 120 (12) ◽  
pp. 1101-1111 ◽  
Author(s):  
V.G. Nealis ◽  
T.J. Lysyk
Keyword(s):  
Instar Larva ◽  
Jack Pine ◽  
Alternative Methods ◽  
Northern Ontario ◽  
Percentage Parasitism ◽  
Total Percentage ◽  
Prediction Of Mortality ◽  
Choristoneura Pinus ◽  
Jack Pine Budworm ◽  
Choristoneura Pinus Pinus

AbstractData on the distribution of overwintering jack pine budworm (Choristoneura pinus pinus Free.) collected between 1985 and 1987 in northern Ontario are used to develop guidelines for sampling this stage of the budworm. Two alternative methods of expressing budworm density are considered: counting the number of budworms per metre of branch and counting the number per square metre of branch bark surface area. Estimates of budworm density for three levels in the tree’s crown are given for 4 site-years.Entire branches are recommended as the sample units as the use of 60-cm branch-tip sections resulted in consistent underestimation of actual density per branch. Jack pine budworm density did not vary among cardinal compass directions and was generally highest at mid-crown levels.The distributions of two parasitoids, Apanteles fumiferanae Vier. and Glypta fumiferanae (Vier.), which overwinter as an egg or first-instar larva within the jack pine budworm, also were considered. Apanteles was the most abundant parasitoid at all crown levels at all sites examined. Percentage parasitism by Apanteles was highest and that by Glypta was lowest on the branch-tip sections in relation to the branch-basal section, but total percentage parasitism was relatively constant over the entire branch, throughout the tree crown, and from tree to tree. Consequently, the sampling method for jack pine budworm is easily extended for estimating the rate of parasitism and therefore for providing a prediction of mortality that results from these two common parasitoids.

Analysis and modelling of cohort life tables of jack pine seed cones

1994 ◽  
Vol 24 (8) ◽  
pp. 1579-1592 ◽  
Author(s):  
Peter De Groot ◽  
Richard A. Fleming
Keyword(s):  
Mortality Rate ◽  
Jack Pine ◽  
Life Tables ◽  
Red Pine ◽  
Northern Ontario ◽  
The North ◽  
Pine Cone ◽  
Seed Cone ◽  
Jack Pine Budworm ◽  
Specific Mortality

Life tables for jack pine (Pinusbanksiana Lamb.) seed cones were constructed for cohorts at three sites in northern Ontario from 1985–1987 to determine the causes and temporal sequence of mortality. Seed cone abortion and feeding by the red squirrel, Tamiasciurushudsonicus (Erxleben), accounted for 65–75% of mortality. Insects killed about 4% of the total cone crop. Losses from the jack pine budworm, Choristoneurapinuspinus Freeman, the webbing coneworm, Dioryctriadisclusa Heinrich, and the red pine cone borer, Eucosmamonitorana Heinrich, combined, accounted for about 1%, while the cone resin midge, Asynaptahopkinsi Felt, and the red pine cone beetle, Conophthorusresinosae Hopkins, each killed about 1%. Three models, linear-exponential, Gompertz, and Weibull, were examined to describe seed cone survivorship curves, of which the Weibull generally gave concise descriptions and fitted very well. Significantly different patterns of cone survival occurred at different sites during the same period, and at the same site over different periods. The age-specific mortality rate increased with age most slowly in the bottom third of the tree's crown. There were significant differences in the age-specific mortality rate among the north, south, east, and west aspects in the same cohort, but there was no consistent pattern among cohorts, or between trees within a cohort.

The Effect of Jack-pine Staminate Flowers on the Size of Larvae of the Jack-pine Budworm, Choristoneura sp.

1950 ◽  
Vol 82 (2) ◽  
pp. 34-43 ◽  
Author(s):  
R. R. Lejeune
Keyword(s):  
Jack Pine ◽  
New Variety ◽  
Early Stages ◽  
Northwestern Ontario ◽  
Jack Pine Budworm

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.

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