Effects of diapause duration on postdiapause performance of spruce budworm (Lepidoptera: Tortricidae) during mass rearing on artificial diet

2007 ◽  
Vol 139 (6) ◽  
pp. 834-840 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Peter Ebling ◽  
John Dedes ◽  
Doug Pitt
Keyword(s):  
Cold Storage ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Mass Rearing ◽  
Storage Duration ◽  
Performance Variables ◽  
Late Instar ◽  
Neonate Larvae ◽  
Pupal Mass ◽  
Diapause Duration

AbstractThe spruce budworm, Choristoneura fumiferana (Clem.), has an obligatory winter dormancy period that lasts up to 10 months in the field. In the Great Lakes Forestry Centre rearing facility, neonate larvae spin hibernacula in cheesecloth, which is then stored at 2 °C for between 20 and 30 weeks. Although dormancy survival and synchrony of postemergence development are highest when larvae are stored in the cold for 16–35 weeks, it is not known how cold-storage duration affects spruce budworm performance once diapause has been completed. We exposed approximately 9250 second-instar larvae (belonging to three rearing cohorts) to 2 °C for 16, 19, 22, 25, 28, 31, 34, or 37 weeks and monitored various postdiapause performance variables. Increasing cold storage from 16 to 25 weeks or more resulted in small (approximately 10%) increases in dormancy survival and larval development rates (from second instar to pupation), a larger (up to 23%) increase in pupal mass and realized fecundity (number of eggs laid per female), and an increase of at least 25% in late-instar survival (from fifth instar to pupation). The only variable that was negatively affected was the pupal survival, but the decrease was relatively small. Therefore, storing diapausing larvae for at least 25 weeks optimizes postdiapause performance variables that are important for mass-rearing efficiency.

3.5 SUPPRESSION OF SPRUCE BUDWORM POPULATIONS BY TRICHOGRAMMA MINUTUM RILEY, 1982–1986

1990 ◽  
Vol 122 (S153) ◽  
pp. 56-81 ◽  
Author(s):  
S.M. Smith ◽  
D.R. Wallace ◽  
G. Howse ◽  
J. Meating
Keyword(s):  
Choristoneura Fumiferana ◽  
Host Density ◽  
Spruce Budworm ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Curvilinear Relationship ◽  
Egg Masses ◽  
Trichogramma Minutum ◽  
Egg Parasitism ◽  
Release Timing

AbstractThe ability of the egg parasitoid, Trichogramma minutum Riley, to suppress outbreak populations of the spruce budworm, Choristoneura fumiferana (Clemens), was studied annually near Hearst, Ont., from 1982 through 1986. Timing of broadcast parasitoid-releases was linked to spruce budworm moth emergence and oviposition. These phenological relationships were predicted from a regression based on larval development at least 2 weeks before expected emergence; this allowed sufficient time to regulate (program) parasitoid emergence during mass-rearing. Emergence of caged spruce budworm adults was used to monitor moth eclosion in the field. Pheromone traps provided daily information on the activity of male moths and helped to synchronize the parasitoid releases with spruce budworm oviposition. Information on parasitoid activity was obtained from sentinel (laboratory-reared) and naturally occurring spruce budworm egg masses. A curvilinear relationship between the rate of parasitoid release and parasitism of sentinel egg masses was developed. Two parasitoid releases, 1 week apart, early in the oviposition period of spruce budworm, significantly increased parasitism of host eggs by 14–83% and reduced larval populations correspondingly from 42 to 82%. Single releases were less effective and increased parasitism by 0.3–52% (single ground release, 1986). Two parasitoid releases, combined with a spring application of Bacillus thuringiensis Berliner to larval populations, was the most effective strategy and resulted in 83% egg parasitism and 93% larval reduction. Release rates greater than 12–16 × 106 ♀ ♀ T. minutum per hectare were not warranted based on impact and costs. The effects of release timing, weather, host density, and parasitoid quality on the future successful use of T. minutum are discussed.

Interaction of Apanteles fumiferanae (Hymenoptera: Braconidae) and Nosema fumiferanae (Microsporidia) parasitizing spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)

1987 ◽  
Vol 65 (8) ◽  
pp. 2047-2050 ◽  
Author(s):  
V. G. Nealis ◽  
S. M. Smith
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Dry Weight ◽  
Mass Rearing ◽  
Adult Longevity ◽  
Slight Reduction ◽  
Rate Of Development ◽  
Larval Female ◽  
The Relationship ◽  
Larval Parasites

The relationship between a braconid parasitoid, Apanteles fumiferanae, and a microsporidian pathogen, Nosema fumiferanae, two larval parasites frequently coincident in the spruce budworm, Choristoneura fumiferana, was examined in the laboratory. When Apanteles was reared in spruce budworm infected with high levels of Nosema (i.e., more than 20 × 106 spores/mg dry weight), there was a slight reduction in the within-host rate of development of larval female Apanteles, but survival, within-cocoon rate of development, cocoon weight, and adult longevity were not affected. There was no evidence that any stage of Apanteles was infected with spores of Nosema. A few adult female parasitoids were found to carry spores of Nosema on their integuments but it is unlikely that Apanteles is an important vector of the microsporidian. We conclude that these natural enemies of budworm do not interact significantly in their common host. The implications for population dynamics of the spruce budworm and mass rearing of Apanteles are discussed.

Interactions between Bacillus thuringiensis and parasitoids of late-instar larvae of the spruce budworm (Lepidoptera: Tortricidae)

2001 ◽  
Vol 79 (9) ◽  
pp. 1697-1703 ◽  
Author(s):  
Astrid Schoenmaker ◽  
Michel Cusson ◽  
Kees van Frankenhuyzen
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Petri Dish ◽  
Control Treatment ◽  
Eastern Spruce Budworm ◽  
Late Instar ◽  
Host Mortality ◽  
Pathogen Exposure

We investigated interactions between Bacillus thuringiensis Berliner var. kurstaki and parasitoids that attack late instars of the eastern spruce budworm, Choristoneura fumiferana (Clemens). In a petri-dish arena, females of Tranosema rostrale rostrale (Brishke) (Hymenoptera: Ichneumonidae) were able to discriminate between untreated fourth instars and fourth instars that had been given a known dose of a commercial product (Foray 48B). When the choice tests were conducted before host mortality due to B. thuringiensis had occurred among treated larvae (24 h post ingestion), the parasitoid attacked untreated larvae more readily. When females were given a choice between control larvae and treated larvae that were still alive 72 h post ingestion, they were able to discriminate between the two only when the larvae had been treated with at least a 50% lethal dose. Under laboratory conditions, female T. r. rostrale were thus able to detect and avoid treated larvae that exhibited a lethal response to the pathogen, and to a lesser extent larvae that had survived pathogen exposure. The ability of the latter was not apparent under field conditions. When treated and untreated larvae were exposed for 1 week to a complex of indigenous parasitoids in the field, there was no difference between treatments in the rates of parasitism by either T. r. rostrale or Actia interrupta Curran (Diptera: Tachinidae). Parasitism averaged 91% for larvae in the control treatment compared with 92% for larvae treated with Foray 48B. The field data suggest that spruce budworm larvae that survive exposure to B. thuringiensis are just as likely to be parasitized as unexposed, healthy larvae. This means that prolonged development of late-instar spruce budworm larvae after treatment with B. thuringiensis could possibly result in increased attack rates by parasitoids.

Observations on the feeding behaviour of late-instar larvae of Choristoneura fumiferana

2010 ◽  
Vol 142 (4) ◽  
pp. 388-392 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Sylvain Espinasse
Keyword(s):  
Bacillus Thuringiensis ◽  
Feeding Behaviour ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Eastern Spruce Budworm ◽  
Late Instar ◽  
Feeding Bout ◽  
Subsequent Interval ◽  
Observation Period

AbstractLaboratory observations revealed that late-instar larvae of the eastern spruce budworm (Choristoneura fumiferana (Clemens)) (Lepidoptera: Tortricidae) spend most of their time spinning, wandering, and resting; less than 10% is spent feeding. Larvae feed in a discontinuous pattern of short feeding bouts separated by much longer intervals of nonfeeding activity. Over a 2 h observation period, feeding bouts averaged 2.2 min and were separated by 17.4 min intervals for 4th-instar larvae as compared to 3.3 min bouts separated by 33.4 min intervals for 5th-instar larvae. The duration of a feeding bout was positively correlated with the duration of the subsequent interval, not with the duration of preceding intervals, suggesting that feeding-bout frequency is governed primarily by post-ingestion processes. It is postulated that short feeding bouts followed by long intervals limit the window for ingesting an efficacious dose of aerially applied insecticides such as Bacillus thuringiensis.

DIAPAUSE DEVELOPMENT OF SPRUCE BUDWORM LARVAE, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE), AT TEMPERATURES FAVOURING POST-DIAPAUSE DEVELOPMENT

1996 ◽  
Vol 128 (1) ◽  
pp. 167-169 ◽  
Author(s):  
Er-Ning Han ◽  
Eric Bauce
Keyword(s):  
Cold Storage ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Diapause Development

Requirements for diapause development of larvae of Choristoneura fumiferana have been generally believed to be met by temperatures of 2°C or below for a period ranging from 14 to 20 weeks (see review by Sanders 1991), whereas those favourable for post-diapause development were shown to be above 11°C (Régnière 1990). However, we noticed that a large number of larvae completed diapause after 10 weeks at 18°C without any cold storage. The following experiment was carried out to confirm this result.

Infection by Nosema fumiferanae (Microsporidia: Nosematidae) and feeding on previous-year’s foliage do not interact in affecting late instars of the spruce budworm (Lepidoptera: Tortricidae)

2015 ◽  
Vol 148 (2) ◽  
pp. 163-170
Author(s):  
Kees van Frankenhuyzen ◽  
Yuehong Liu
Keyword(s):  
Laboratory Experiments ◽  
Development Time ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Pupal Stage ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Linear Fashion ◽  
Two Factors ◽  
Pupal Mass

AbstractInfection by Nosema fumiferanae (Thomson) (Microsporidia: Nosematidae) and feeding by late-instars on previous year’s foliage due to depletion of current year’s growth (also known as back-feeding) are likely to co-occur in high-density outbreak populations of the spruce budworm (Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae)). We tested the hypothesis that effects of the two factors on larval fitness are exacerbated by their interaction. Twigs of balsam fir (Abies balsamea Linnaeus; Pinaceae) with or without new-growth shoots were fed to sixth-instar offspring from uninfected, moderately infected, or highly infected females in two laboratory experiments. Pupal mass and time to reach the pupal stage were significantly affected by infection and back-feeding but not by their interaction. Pupal mass decreased and development time increased with increasing spore burden in a linear fashion. Back-feeding had a significant effect on survival to the pupal stage, but infection did not, nor did their interaction. The relatively small changes in survival, pupal mass, and development time caused by infection and back-feeding were additive. The results thus refute our hypothesis that infection by N. fumiferanae and forced feeding on last year’s foliage by late instars are likely to interact in affecting spruce budworm recruitment in older outbreak populations.

scholarly journals Cold storage and gamma irradiation of Sitotroga cerealella Olivier eggs (Lepidoptera: Gelechiidae) in relation to the success of parasitism by Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae)

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Naglaa F. Abdel-Hameid ◽  
I. R. M. Elzoghby ◽  
A. L. Mehany ◽  
W. A. A. Sayed
Keyword(s):  
Gamma Irradiation ◽  
Cold Storage ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Sitotroga Cerealella ◽  
Trichogramma Evanescens ◽  
Control Programs ◽  
Angoumois Grain Moth ◽  
Rearing Techniques ◽  
The Times

AbstractThe performance of parasitism by the egg parasitoid, Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) on eggs of Angoumois grain moth, Sitotroga cerealella Olivier (Lepidoptera: Gelechiidae) was investigated under cold storage and gamma irradiation treatments of the host eggs. Cold storage treatment could improve the parasitoid mass rearing techniques and reduced the costs of biological control programs, while gamma irradiation might be used as a supplementary support at the times of high demand. The suitability of the S. cerealella eggs, stored at – 20 °C for 0.5, 1, or 2 h. as a host for T. evanescens was evaluated. The sensitivity of S. cerealella eggs to gamma irradiation treatments and the acceptability of irradiated eggs for parasitism by T. evanescens females for the parental P and F1 generations were examined. The results revealed that parasitism was drastically reduced more than adult’s emergence and sex-ratio (% of females) after cold storage periods of S. cerealella eggs. Moreover, the parasitism percentages were relatively reduced to (97.1, 96.1, 93.03, and 92.7 %) after irradiating the S. cerealella eggs at 40, 60, 80, and 100 Gy, respectively than the control (97.3% emergence). The percentages of emergence and females’ percent were slightly decreased by gamma irradiation doses, while, equal preferred by the F1 generation of parasitoid that produced from irradiated S. cerealella eggs.

Derivation of Pheromone-Based Larval Thresholds in Spruce Budworm Accounting for Distance to Defoliated Forest Stands

2021 ◽  
Author(s):  
Marc Rhainds ◽  
Ian DeMerchant ◽  
Pierre Therrien
Keyword(s):  
Boreal Forests ◽  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Intervention Strategy ◽  
Spruce Budworm ◽  
Interactive Effects ◽  
The Novel ◽  
Forest Stands ◽  
General Guideline ◽  
Number Of Males

Abstract Spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is the most severe defoliator of Pinaceae in Nearctic boreal forests. Three tools widely used to guide large-scale management decisions (year-to-year defoliation maps; density of overwintering second instars [L2]; number of males at pheromone traps) were integrated to derive pheromone-based thresholds corresponding to specific intergenerational transitions in larval densities (L2i → L2i+1), taking into account the novel finding that threshold estimates decline with distance to defoliated forest stands (DIST). Estimates of thresholds were highly variable between years, both numerically and in terms of interactive effects of L2i and DIST, which limit their heuristic value. In the context of early intervention strategy (L2i+1 > 6.5 individuals per branch), however, thresholds fluctuated within relatively narrow intervals across wide ranges of L2i and DIST, and values of 40–200 males per trap may thus be used as general guideline.

Weather and Outbreaks of the Spruce Budworm in the Province of Quebec from 1939 to 1956

1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
The Past ◽  
Forest Regions ◽  
Tree Component ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.

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