A GEOGRAPHICAL CLINE IN EGG WEIGHTS IN CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE) AND ITS SIGNIFICANCE IN POPULATION DYNAMICS

1983 ◽  
Vol 115 (9) ◽  
pp. 1103-1108 ◽  
Author(s):  
G. T. Harvey
Keyword(s):  
Population Dynamics ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Pupal Weight ◽  
Egg Weight ◽  
Winter Conditions ◽  
The Mean

AbstractThe mean weights of the initial eggs (Ei) of the spruce budworm, Choristoneura fumiferana (Clem.), vary within and between populations. Measurements of collections from across the range of this species reveal the presence of a cline directly related to latitude and longitude of the collection source. Collection mean Ei values range from 0.219 mg in the northwest to 0.157 mg in the southeast. A similar cline, also related to latitude but negative in slope, is demonstrated for the number of eggs per unit pupal weight. This cline also finds expression in changing slope of fecundity/pupal weight regressions. The cline in egg weight appears to be an adaptation to winter conditions across the range of this insect and should be considered in population dynamics.

ENVIRONMENTAL AND GENETIC EFFECTS ON MEAN EGG WEIGHT IN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1983 ◽  
Vol 115 (9) ◽  
pp. 1109-1117 ◽  
Author(s):  
G. T. Harvey
Keyword(s):  
Larval Development ◽  
Genetic Control ◽  
Environmental Control ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Genetic Constitution ◽  
Laboratory Studies ◽  
Artificial Diets ◽  
Egg Weight ◽  
The Mean

AbstractLaboratory studies of the mean weights of initial eggs (Ei) of the spruce budworm, Choristoneura fumiferana (Clem.), show that this value is determined by the genetic constitution of the female moth and is relatively independent of environmental control. Dietary differences experienced by the female during larval development, and originating from different hosts or from reduced nutrient levels in artificial diets, did not affect Ei values; however, depletion of nutrients sufficient to reduce fertility greatly did reduce Ei. Temperature conditions during the ultimate larval and pupal stages influence Ei values which vary inversely. Mean egg weights are strongly heritable and are readily selected for, thereby demonstrating the presence of strong genetic control.

MEAN WEIGHT AND REARING PERFORMANCE OF SUCCESSIVE EGG CLUSTERS OF EASTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1977 ◽  
Vol 109 (4) ◽  
pp. 487-496 ◽  
Author(s):  
G. T. Harvey
Keyword(s):  
Cluster Size ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Laboratory Studies ◽  
Egg Weight ◽  
Laboratory Rearing ◽  
The Third ◽  
Eastern Spruce Budworm ◽  
Wet Weight ◽  
The Mean

AbstractDetailed laboratory studies of mated spruce budworm (Choristoneura fumiferana (Clem.)) show that the number of eggs per day, mean cluster size, and mean wet weight of the eggs gradually decrease during the period of oviposition of individual moths. The term mean weight of initial eggs (Ei) is defined and compared with other measurements of mean egg weight based on total egg complement or parts of it. Ei is 6%–12% greater than the mean egg weight based on all eggs laid. In spite of variation in pattern of egg weight distribution among moths, Ei appears to express satisfactorily the differences in mean egg weight among moths and can be used to survey egg weights among populations.Laboratory rearing studies of individual clusters indicate slightly slower emergence rates (seconds from hibernacula), greater survival, and smaller proportions of male pupae in the third and fourth quartiles of the egg complement; there were no differences in pupal weights related to cluster order. There is no ready explanation for this improved survival of larvae from eggs known to be smaller.Implications of these results for the population dynamics of the spruce budworm are discussed. The more stressful conditions encountered in the natural environment may counteract the apparently better survival of individuals from the latter part of the egg complement.

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

1990 ◽  
Vol 122 (6) ◽  
pp. 1271-1272 ◽  
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.

THE EFFECT OF A MICROSPORIDIAN PARASITE ON THE DEVELOPMENT, REPRODUCTION, AND MORTALITY OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.)

1958 ◽  
Vol 36 (4) ◽  
pp. 499-511 ◽  
Author(s):  
H. M. Thomson
Keyword(s):  
Initial Dose ◽  
Male Fertility ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Malpighian Tubules ◽  
Pupal Weight ◽  
Adult Longevity ◽  
Microsporidian Parasite ◽  
Pupal Development ◽  
First Instar

Infection of the spruce budworm, Choristoneura fumiferana (Clem.), by the microsporidian parasite Perezia fumiferanae Thorn, retards both larval and pupal development and reduces pupal weight, fecundity, and adult longevity. These effects are more pronounced among the female insects. There is no evidence that the parasite affects male fertility, mate choice, or the fertility of eggs produced. The parasite causes some mortality, most of which occurs before the fifth instar. Among larvae infected orally, mortality seems to be related to the size of the initial dose. Mortality occurs equally in both sexes. The development and survival of the first instar and overwintering second instar are not affected by the parasite. It is suggested that the parasite causes most of the observed results by reducing the insect's ability to assimilate its food. Mortality, however, is believed to be due to the destruction of the mid-gut or Malpighian tubules.

LIFE HISTORY CHARACTERISTICS OF ELACHERTUS CACOECIAE (HYMENOPTERA: EULOPHIDAE), AN ECTOPARASITOID OF SPRUCE BUDWOR LARVAE, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1998 ◽  
Vol 130 (2) ◽  
pp. 215-229 ◽  
Author(s):  
Jeffrey G. Fidgen ◽  
Eldon S. Eveleigh
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Pupal Stage ◽  
Spruce Budworm ◽  
Oviposition Period ◽  
Host Feeding ◽  
Adult Males ◽  
Alternate Host ◽  
Laboratory Development ◽  
The Mean

AbstractWe carried out a 2-year study to elucidate the biology of the gregarious, idiobiont ectoparasitoid Elachertus cacoeciae (Howard) by placing (implanting) laboratory-reared spruce budworm larvae [Choristoneura fumiferana (Clemens)] on current-year balsam fir (Abies balsamea L.) shoots in the field, simulating low (endemic) densities of the budworm. Spring female E. cacoeciae attacked fourth-, fifth-, and sixth-instar budworm larvae, beginning near the predicted peak of the fourth instar and ending about 10–12 days after the predicted peak of the pupal stage of the wild budworm population. The mean (±SE) brood size of spring females was 2.9 ± 0.3 E. cacoeciae pupae per host. The proportion of females increased during the season, with many broods consisting of 100% females late in the season. In 1994 and 1995, the mean proportion of females was 0.74 ± 0.05 and 0.79 ± 0.05, respectively. In the laboratory, development time from eggs to adults was approximately 20 days at 20.6 °C. Adult males provided with honey water lived 43.6 ± 3.2 days, whereas females provided with hosts and honey water lived 90.1 ± 6.6 days. Spring females had a pre-oviposition period of 11.5 ± 1.3 days, resulting in a generation time (egg to egg) of ~31 days. The oviposition period lasted 76.3 ± 7.7 days during which time spring females parasitized 19.2 ± 1.9 hosts, and produced a clutch size of 4.9 ± 0.4 eggs per host, for a lifetime fecundity of 96.8 ± 14.7 eggs. The post-oviposition period was 18.5 ± 3.7 days. Throughout their lifetime, spring females host fed only (host feeding without oviposition) on an additional 9.3 ± 1.9 hosts. Approximately 2% of pupae developing from spring females overwintered, whereas approximately 95% of pupae developing from summer females overwintered. Laboratory results for summer females suggest that they may be adapted to parasitizing alternate host(s) rather than spruce budworm.

Does nutrition-related stress carry over to spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) progeny?

2002 ◽  
Vol 92 (2) ◽  
pp. 101-108 ◽  
Author(s):  
N. Carisey ◽  
É. Bauce
Keyword(s):  
Choristoneura Fumiferana ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Pupal Weight ◽  
Total Soluble Sugar ◽  
First Instar ◽  
Parental Nutrition ◽  
Biological Performance

AbstractThree different patterns of feeding of sixth-instar spruce budworm, Choristoneura fumiferana Clemens were simulated in the laboratory. Larvae were fed artificial diets whose nitrogen and total soluble sugar contents varied according to levels similar to those found in three types of balsam fir, Abies balsamea (L.) Miller foliage (current-year foliage from middle and lower crown sections and one-year-old foliage). The biological performance of offspring was studied according to the nutrition of their parents. Although food quality had no impact on pupal weight of female parents and individual mean egg weight, progeny fitness was influenced by parental nutrition. Old foliage simulated diet, poor in nitrogen, clearly affected the early larval development of progeny, especially the percent of egg hatch and first-instar survival. Lower crown current-year foliage simulated diet, with low total soluble sugar content, reduced the first-instar survival of the progeny. However, the selective pressure exerted by low food qualities on the parental generation and on the early stages of their progenies resulted in C. fumiferana populations having higher tolerance to starvation and higher survival after the diapause period. These results highlighted the potentially direct and indirect effects of C. fumiferana parental nutrition on the next generation. The patterns of feeding of parental generations would appear to affect the quality and size of subsequent populations through several selections on the different life-history stages of both generations.

Périodicité et synchronisme des épidémies de la tordeuse des bourgeons de l'épinette au Québec

2003 ◽  
Vol 33 (10) ◽  
pp. 1947-1961 ◽  
Author(s):  
Yves Jardon ◽  
Hubert Morin ◽  
Pierre Dutilleul
Keyword(s):  
Population Dynamics ◽  
Choristoneura Fumiferana ◽  
Local Population ◽  
Spruce Budworm ◽  
Periodic Component ◽  
Moran Effect ◽  
Regional Effect ◽  
Migration Effect ◽  
Different Types ◽  
Insect Populations

A time series analysis was performed on 32 dendrochronological chronologies using Dutilleul's multi frequential periodo gram. Our aim was to estimate the periodicities of spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks in the province of Quebec. Our analysis estimated a signal of 25-38 years corresponding to spruce budworm outbreaks. Analyses conducted in the 20th century indicated the existence of true periodicities in half of the series suggesting local population dynamics. These periodicities were estimated to be 29-34 years. For the other series, outbreaks were explained by the addition of a second periodic component to the fundamental periodicity. These combined periodicities (pseudoperiodicities or complex periodicities) described most of the 130-year series analysed. The lack of several outbreaks explained part of the combined periodicity. The results suggest a migration effect and complex local population dynamics. A third periodic component explains the double epidemic waves. These estimated periodicities are often similar and in phase. We believe that a common regional effect (the Moran effect) acts on the minor fluctuations of the insect populations and helps synchronize the outbreaks. This research shows that different types of outbreak dynamics can be found within a same insect species.

Dendrochronological reconstruction of spruce budworm outbreaks in northern Maine, USA

2007 ◽  
Vol 37 (3) ◽  
pp. 523-529 ◽  
Author(s):  
Shawn Fraver ◽  
Robert S. Seymour ◽  
James H. Speer ◽  
Alan S. White
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Growth Patterns ◽  
Eastern Canada ◽  
Eastern Spruce Budworm ◽  
History Of ◽  
Northern White Cedar ◽  
The Mean ◽  
Overstory Trees ◽  
Slow Growing

Using dendrochronological analyses, we reconstructed a 300 year history of eastern spruce budworm ( Choristoneura fumiferana (Clem.)) outbreaks in northern interior Maine. By analyzing radial growth patterns from the budworm host, red spruce ( Picea rubens Sarg.), and nonhost, northern white cedar ( Thuja occidentalis L.), we identified five outbreaks beginning ca. 1709, 1762, 1808, 1914, and 1976, all of which have been documented from eastern Canada. However, little or no evidence was found in our study for the 1830s, 1870s, or 1940s outbreaks also documented there. The mean outbreak return interval in our study (67 years) was roughly twice that postulated for eastern Canada. Differences in forest types, and associated stand dynamics, between the regions may explain the longer return intervals, and consequently the absence of these three outbreaks in Maine. Results also indicate that small, slow-growing trees exhibit a budworm signal very similar to that of overstory trees, once tree-ring series have been properly standardized.

ASPECTS OF MATING IN THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1971 ◽  
Vol 103 (8) ◽  
pp. 1121-1128 ◽  
Author(s):  
I. Outram
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Normal Numbers ◽  
Duration Of Copulation ◽  
The Mean ◽  
Old Females

AbstractNormal matings of Choristoneura fumiferana (Clem.) resulted in the transfer of single, persistent spermatophores. The mean duration of copulation was 4 hours with a range from 21/2 to 81/2 hours. All the first matings of males were fertile and the spermatophores were large, while an increasing proportion of the subsequent matings were infertile and the spermatophores became progressively smaller. Only fertilized females laid normal numbers of eggs. There was no evidence to show that insemination can be accomplished without the transfer of a spermatophore. However, the presence of a spermatophore in the bursa of the female was not always indicative of successful insemination.Males mated only once within a 24-hour period; they were least responsive to females just after emergence (< 0.5 day old) and most responsive when 2 to 4 days old. Females mated most readily when < 0.5 day old and became progressively less attractive or less receptive with age. Mated females were not as attractive as unmated females.

scholarly journals Quantifying and predicting population connectivity of an outbreaking forest insect pest

2021 ◽  
Author(s):  
Jeremy Larroque ◽  
Julian Wittische ◽  
Patrick M. A. James
Keyword(s):  
Population Dynamics ◽  
Landscape Connectivity ◽  
Choristoneura Fumiferana ◽  
Insect Pest ◽  
Management Strategies ◽  
Temporal Stability ◽  
Spruce Budworm ◽  
Population Connectivity ◽  
Outbreak Area ◽  
Future Landscape

Abstract Context Dispersal has a key role in the population dynamics of outbreaking species such as the spruce budworm (Choristoneura fumiferana) as it can synchronize the demography of distant populations and favor the transition from endemic to epidemic states. However, we know very little about how landscape structure influences dispersal in such systems while such knowledge is essential for better forecasting of spatially synchronous population dynamics and to guide management strategies. Objectives We aimed to characterize the spatial environmental determinants of spruce budworm dispersal to determine how these features affect outbreak spread in Quebec (Canada). We then apply our findings to predict expected future landscape connectivity and explore its potential consequences on future outbreaks. Methods We used a machine-learning landscape genetics approach on 447 larvae covering most of the outbreak area and genotyped at 3562 SNP loci to identify the main variables affecting connectivity. Results We found that the connectivity between outbreak populations was driven by the combination of precipitation and host cover. Our forecasting suggests that between the current and next outbreaks, connectivity may increase between Ontario and Quebec, and might decrease in the eastern part, which could have the effect of limiting outbreak spread from Ontario and Quebec to the eastern provinces. Conclusions Although we did not identify any discrete barriers, low connectivity areas might constrain dispersal in the current and future outbreaks and should in turn, be intensively monitored. However, continued sampling as the outbreak progresses is needed to confirm the temporal stability of the observed patterns.

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