ESTIMATED EGG DEPOSITION BY INVADING SPRUCE BUDWORM MOTHS (LEPIDOPTERA: TORTRICIDAE)

1978 ◽  
Vol 110 (6) ◽  
pp. 609-615 ◽  
Author(s):  
C. A. Miller ◽  
D. O. Greenbank ◽  
E. G. Kettela
Keyword(s):  
New Brunswick ◽  
Larval Stage ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Light Traps ◽  
Minimum Level ◽  
Egg Deposition ◽  
Baited Traps ◽  
The Impact

AbstractA 4000-ha block of spruce budworm, Choristoneura fumiferana (Clem.), infested forest in western New Brunswick was sprayed repeatedly in 1975 during the larval stage of budworm development. The objective was to reduce the population of the 1975 generation to a minimum level so that most of the following generation eggs found on the block could be attributed to invading females, thus providing data on the impact of moth invasion.The presence of dispersing adults in the airspace over the block was monitored by a ground-based radar unit while light traps and pheromone-baited traps were used to confirm that invasion had taken place. A total egg population of 33.8 masses per m2 of foliage was found on the block and indirect estimates suggest that invading females deposited about 10 of these masses.

scholarly journals Monitoring Spruce Budworm with Light Traps: The Effect of Trap Position

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Marc Rhainds ◽  
Edward G. Kettela
Keyword(s):  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Flight Period ◽  
Light Traps ◽  
Tree Canopies ◽  
Trap Location ◽  
Median Date ◽  
Males And Females ◽  
Highly Correlated

Daily records of adult spruce budworms,Choristoneura fumiferana(Clemens) (Lepidoptera: Tortricidae), captured at light traps at multiple locations in New Brunswick in the 1970s, are analyzed in relation to the physical position of light traps (tree canopies or forest clearings). Captures at light traps deployed in tree canopies were 4–400 times greater than those in forest clearings, especially for males. The phenology of captures (median date or duration of flight period) did not differ in relation to trap location. Captures of both males and females in tree canopies were highly correlated with egg densities, whereas no significant relationship was observed for either sex in forest clearings. Monitoring programs for spruce budworm adults using light traps should be standardized by deploying traps in tree canopies.

scholarly journals Dynamics and Management of Rising Outbreak Spruce Budworm Populations

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 748 ◽  
Author(s):  
Jacques Régnière ◽  
Barry Cooke ◽  
Ariane Béchard ◽  
Alain Dupont ◽  
Pierre Therrien
Keyword(s):  
Population Growth ◽  
Density Dependence ◽  
Natural Enemies ◽  
Choristoneura Fumiferana ◽  
Regional Scale ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Migration Activity ◽  
Larval Stages ◽  
The Impact

Management of spruce budworm, Choristoneura fumiferana (Clem.), outbreak spread requires understanding the demographic processes occurring in low, but rising populations. For the first time, detailed observations were made in the early stages of outbreak development. We sampled populations over a three-year period in both treated and untreated populations in the Lower St-Lawrence region of Quebec, Canada, and measured the density-dependence of survival and population growth rates, and the impact of natural enemies and insecticides. Insecticides tested were Bacillus thuringiensis (Berliner 1915) and tebufenozide. We recorded strong density-dependence of survival between early larval stages and adult emergence, explained largely by the variation of natural enemy impacts and overcrowding. We also observed inverse density-dependence of apparent fecundity: net immigration into lower-density populations and net emigration from the higher, linked to a threshold of ~25% defoliation. Because of high migration rates, none of the 2013 treatments reduced egg populations at the end of summer. However lower migration activity in 2014 allowed population growth to be reduced in treated plots. This evidence lends support to the conclusion that, for a budworm population to increase to outbreak density, it must be elevated via external perturbations, such as immigration, above a threshold density of ~4 larvae per branch tip (L4). Once a population has increased beyond this threshold, it can continue growing and itself become a source of further spread by moth migration. These findings imply that populations can be brought down by insecticide applications to a density where mortality from natural enemies can keep the reduced population in check, barring subsequent immigration. While we recognize that other factors may occasionally cause a population to exceed the Allee threshold and reach outbreak level, the preponderance of immigration implies that if all potential sources of significant numbers of moths are reduced on a regional scale by insecticide applications, a widespread outbreak can be prevented, stopped or slowed down by reducing the supply of migrating moths.

THE MATING STATUS OF SPRUCE BUDWORM MALES, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE), CAUGHT IN PHEROMONE-BAITED TRAPS

1986 ◽  
Vol 21 (3) ◽  
pp. 254-262 ◽  
Author(s):  
J. Chris Bergh ◽  
William D. Seabrook
Keyword(s):  
Choristoneura Fumiferana ◽  
Ejaculatory Duct ◽  
Spruce Budworm ◽  
Sampling Period ◽  
Male Mating ◽  
Mating Status ◽  
Mating History ◽  
Baited Traps ◽  
Significant Difference ◽  
Flight Season

The mating status of recently-mated male spruce budworm moths, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae), caught in traps baited with five different treatments was indexed. During two sampling periods at two test sites both virgin and mated C. fumiferana males were trapped. Significantly more unmated males were captured early in the flight season. There was no significant difference between the proportion of mated and unmated males caught near the end of the flight season. Within sampling periods and sites there were not significant differences among treatments in the proportion of mated males captured nor were these proportions significantly different within sampling periods and between sites. Within sites and between sampling periods the proportion of mated males captured was significantly different, with more mated males being trapped during the later sampling period. The four lepidopteran species for which methodologies have been developed for indexing male mating status are compared with respect to the nature and behaviour of the colored ejaculatory duct fluids that are used as markers of mating history. Current limitations of the method are discussed and possible solutions to these are suggested.

The Interaction of the Spruce Budworm, Choristoneura fumiferana (Clem.), and the Parasite Glypta fumiferanae (Vier.)

1960 ◽  
Vol 92 (11) ◽  
pp. 839-850 ◽  
Author(s):  
C. A. Miller
Keyword(s):  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Actual Number ◽  
Emergence Period ◽  
Realistic Estimate ◽  
Host Generation

This is the second of a series of papers (Miller, 1959) describing the interaction of primary parasites and the spruce budworm, Choristoneura fumiferana (Clem.), based on data collected during an outbreak of the budworm in northern New Brunswick during the period 1947–1958. The first paper showed that the interaction between the spruce budworm and Apanteles fumiferanae Vier. is adequately described by the general mathematicai model developed by Watt (1959). The data on the parasite Glypta fumiferanae (Vier.) to be presented in this paper are also analysed by means of Watt's model and consequently the method is essentially the same. There is, however, one important difference. In the case of A. fumiferanae, the estimated number of adult parasites was only an index based on the potential number emerging from the previous host generation. The observed density of G. fumiferanae is a more realistic estimate. It is based on the actual number of cocoons found on the foliage during the adult emergence period.

Evidence of DDT Resistance in Populations of Spruce Budworm, Choristoneura fumiferana (Clem.), From DDT-sprayed Areas of New Brunswick

1965 ◽  
Vol 97 (12) ◽  
pp. 1281-1293 ◽  
Author(s):  
A. P. Randall
Keyword(s):  
New Brunswick ◽  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Data Interpretation ◽  
Fuel Oil ◽  
Susceptible Population ◽  
Mortality Curve ◽  
Progressive Development ◽  
Ddt Resistance

AbstractA series of laboratory toxicological experiments using various concentrations of oil formulated DDT solutions (AR-50/fuel oil (2:7 V/V)) was carried out on 5th and 6th instar spruce budworm larvae collected in the field from DDT-sprayed and untreated areas of New Brunswick, Canada, and Maine, U.S.A.Results obtained in 1959, 1961, and 1962 with larvae collected from isolated, unsprayed areas in New Brunswick showed a consistent, straight log-dosage probit mortality curve. Larvae collected in 1962 and 1963 from infestation centres previously subjected to three, four, and five applications of non-consecutive large-scale aerial sprays of DDT showed a significant departure from the straight log-dosage probit curve previously obtained. The departure occurs as a change in the shape of the curve as well as a shift to the higher concentration range of DDT. The magnitude of change appears to be correlated with the number of sprays to which the population was exposed. Results obtained in 1962 and 1963, from untreated control and inter-spray areas, bounded by DDT-sprayed forest lands, showed a small but significant departure from the normal straight probit line of a susceptible population. These changes are indicative of a progressive development of DDT resistance in wild populations of spruce budworm.Studies on the effect of the tolerance of spruce budworm larvae within instar classes to the action of DDT showed that the early phase of instar development immediately after moulting is more susceptible to the action of DDT, whereas the latter phase of instar development immediately prior to moulting is more tolerant to topical application of DDT than the average for the instar. This effect is evident in both susceptible and resistant populations.The data interpretation assumes that a deviation from the straight line probit dosage – mortality curve is indicative of a difference in the DDT-susceptibility factor of the budworm population and that in the course of the tests, the amount of toxicant causing mortality was not proportional to the dosage.

Grazing by the gastropod, Lacuna vincta, in the lower intertidal area at Musquash Head, New Brunswick, Canada

1983 ◽  
Vol 63 (3) ◽  
pp. 725-736 ◽  
Author(s):  
Martin L. H. Thomas ◽  
Frederick H. Page
Keyword(s):  
New Brunswick ◽  
Egg Production ◽  
Algal Species ◽  
Egg Mass ◽  
Intertidal Area ◽  
Mass Distributions ◽  
Lacuna Vincta ◽  
Egg Deposition ◽  
Large Numbers ◽  
The Impact

Lacuna vincta appeared at Musquash Head, New Brunswick, in large numbers from June to August 1981 principally on lower midlittoral and infralittoral fringe Fucus edentatus. The population reached a mean maximum of 280/m2 in June; by mid September the animals had disappeared. The L. vincta grazed heavily and deposited egg masses on Fucus edentatus but little on other species. All fine and filamentous and encrusting algal species and rock were avoided for egg deposition. Egg mass abundance peaked with the population in June with a mean of 180/m2. Mean egg production in June was 83000/m2.Both snail and egg mass distributions were correlated with the percentage cover of F. edentatus, reaching a maximum at 40–75 cm above mean low tide level.The snails ranged in length from 2–7 mm, consisting of three cohorts from different larval settlements. Growth was rapid in July averaging 0·6 mm/month slowing later.The food plant Fucus edentatus showed a heavy impact of the herbivore. Weight reductions attributable to grazing rose from 56 % in June to 79 % in August and grazed plants tended to thicken rather than elongate with growth. Grazing removed about 79 % of the net production of F. edentatus which averaged 61 g dry wt/m2/day. The impact of the L. vincta population on F. edentatus seems extraordinarily severe.

Biological Consequences in Streams of Aerial Spraying with Fenitrothion Against Spruce Budworm in New Brunswick

1975 ◽  
Vol 10 (1) ◽  
pp. 84-88 ◽  
Author(s):  
H.A. Hall ◽  
D.C. Eidt ◽  
P.E.K. Symons ◽  
D. Banks
Keyword(s):  
New Brunswick ◽  
Forest Cover ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Weather Conditions ◽  
Field Studies ◽  
Early Summer ◽  
Fish Biomass ◽  
Organophosphate Insecticide ◽  
Fish Food

Abstract The effects of the organophosphate insecticide fenitrothion in streams in New Brunswick from operational spraying against spruce budworm larvae, Choristoneura fumiferana (Clem.), have been investigated for four years. A number of streams have been studied and several agencies have documented insecticide concentrations in streams, effects of the insecticide on benthos drift and mortality, changes in benthos standing crop, and changes in fish populations, biomass, and growth. The concentration of fenitrothion found in streams immediately following forest spraying by aircraft varies greatly and is influenced by spray regime, weather conditions, forest cover, and water depth. At application rates of 210 g/ha or two applications of 140 g/ha, fenitrothion concentrations in streams with one exception were less than 15 ppb. Concentrations in streams usually peaked within the first hour following spray application and diminished to less than 1.0 ppb within 24 to 48 hrs. Insecticide applications at 210 g/ha have resulted in measurable concentrations of fenitrothion in streams as far as 4.0 km from the area of application. Using nets, sharply increased numbers of drifting Ephemeroptera and Plecoptera were measured in several streams that had peak fenitrothion concentrations up to 7 .6 ppb, following operational sprays over all or part of the drainage basins. Benthic sampling in one stream sprayed with fenitrothion in 1971, 1972, and 1973, but not in 1974, indicated a substantial decline in benthos between 1971 and 1972, and that recovery had not occurred by 1974. Kill of arthropods in another stream, containing a peak fenitrothion concentration of 6.38 ppb, was measured using drift nets. The stoneflies Leuctra spp. , Amphinemoura spp., and the mayflies, Baetis spp. were most strongly affected, although benthos sampling did not indicate a decline in numbers. Field studies in three sprayed streams suggested that early summer increases in fish biomass may be slowed by the spray program. In field and laboratory experiments, extreme doses were necessary to affect fish behaviour and survival. Evidence indicates that at worst the forest spray program in New Brunswick may sometimes reduce normal summer increases in fish biomass through a reduction in fish-food organisms. It is concluded that in streams the consequences of spruce budworm spraying with fenitrothion by the methods and rates studied in New Brunswick are environmentally tolerable.

Windthrow and growth response following a spruce budworm inspired, variable retention harvest in New Brunswick, Canada

2015 ◽  
Vol 45 (6) ◽  
pp. 659-666 ◽  
Author(s):  
Edward A. Wilson ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Growth Response ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Natural Disturbance ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Growth Release ◽  
Variable Retention ◽  
Variable Retention Harvest

Forest management regimes increasingly focus on the emulation of natural disturbance events, e.g., fire or insect outbreaks, to help increase ecosystem sustainability. We determined the residual stand response to a variable retention harvest inspired by spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks in New Brunswick, Canada. Our objectives were to analyze the differences between surviving residual trees and those that succumbed to windthrow and to quantify growth release. The treatment was based on harvesting the estimated spruce budworm outbreak mortality, i.e., 90% of mature balsam fir (Abies balsamea (L.) Mill., 60% of mature spruce (Picea spp.), and no hardwoods. Windthrow increased with the proportion of trees harvested and averaged 52% over 7–9 years in these stands with high balsam fir – spruce content. One-third of 42 harvested plots sustained >30% windthrow, whereas 73% of 11 similar unharvested plots had <10% windthrow. Balsam fir had higher windthrow than spruce at 53% and 41%, respectively. Windthrown balsam fir trees had significantly larger diameters at breast height (DBH, 1.3 m), larger heights, and smaller crown ratios than surviving residual trees. Substantial growth release occurred, with DBH increment of residual trees 48%–64% greater than trees in unharvested plots. Balsam fir and intolerant hardwoods exhibited the largest growth response. We suggest that future spruce budworm inspired harvests in stands with high balsam fir – spruce content use two or three entries about 5 years apart to reduce windthrow.

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