STUDIES ON DIPTEROUS PARASITES OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA.TORTRICIDAE): VI. PHOROCERA INCRASSATA SMITH (DIPTERA:TACHINIDAE)

1958 ◽  
Vol 36 (4) ◽  
pp. 453-462 ◽  
Author(s):  
H. C. Coppel
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Immature Stages ◽  
Eastern Canada ◽  
First Instar

Phorocera incrassala Smith, which was transferred from Western to Eastern Canada for release against the spruce budworm, Choristoneura fumiferana (Clem.), deposits microtype eggs on leaves, which are later ingested by the host. Eggs hatch immediately after ingestion, but the parasite does not develop beyond the first instar until the host pupates. The larva then develops rapidly, matures in 10 days, and forms its puparium within the host pupal case. The adult emerges in 12 to 14 days. No information is available on the overwintering habits. Among the important characters for identifying the immature stages of P. incrassala are the buccopharyngeal apparatus and the anterior and posterior spiracles.

THE OCCURRENCE AND NATURE OF DIAPAUSE-FREE DEVELOPMENT IN THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE)

1957 ◽  
Vol 35 (4) ◽  
pp. 549-572 ◽  
Author(s):  
George T. Harvey
Keyword(s):  
Environmental Conditions ◽  
Behavior Pattern ◽  
Choristoneura Fumiferana ◽  
Continuous Light ◽  
Spruce Budworm ◽  
Light Treatment ◽  
Complex Behavior ◽  
Eastern Canada ◽  
First Instar ◽  
Free Development

Spruce budworm populations in Eastern Canada are effectively univoltine. After hatching, the larva follows a complex behavior pattern that leads to the building of a hibernaculum in which it molts and spends the winter months without feeding. This pattern seems to be independent of environmental conditions, except as they affect the rate at which the component events occur, and, in the absence of any evidence to the contrary, must be considered as inherent.Laboratory studies have shown that in 62% of the families produced by matings of field-collected individuals at least one larva can develop without diapause if subjected to long photoperiods (at 71° F.); on the average 3 to 4% of the second-instar larvae in such progenies can forego diapause. Selection over six generations yielded a strain that, if subjected to continuous light in the laboratory, is virtually free from diapause. This stock has been reared for a further six generations and still retains this photoperiod dependence. Behavior is usually normal during hibernaculum construction and molting, but then the larvae vacate their shelters, feed readily, and develop without any delay. No associated differences have yet been found between non-diapause (N-D) and normal (D) insects. The ability to develop without diapause is apparently determined by multiple genes; it is not sex-linked but may be to some extent sex-controlled.Diapause-free development in this strain results only when first-instar larvae are exposed to a photoperiod of at least 15 hours, shorter times resulting in almost universal diapause and longer times giving a progressively greater proportion of N-D insects, approaching 100% in continuous light. This response is reduced by lower temperatures. Potential N-D insects deprived of a light-treatment behave as normal D insects; under appropriate conditions of light their progeny in turn develop without diapause.

STUDIES ON DIPTEROUS PARASITES OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE): III. CEROMASIA AURICAUDATA TNS. (DIPTERA: TACHINIDAE)

1954 ◽  
Vol 32 (3) ◽  
pp. 144-156 ◽  
Author(s):  
H. C. Coppel ◽  
M. G. Maw
Keyword(s):  
Life History ◽  
Larval Stage ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Immature Stages ◽  
Eastern Canada ◽  
Mature Larva ◽  
Rearing Methods ◽  
Tachinid Parasite

The tachinid parasite Ceromasia auricaudata Tns., which had been transferred from Western to Eastern Canada for release against the spruce budworm Choristoneura fumiferana (Clem.), is an insect that deposits microtype eggs on leaves which are later ingested by the host. Eggs hatch immediately after ingestion, but the parasite does not develop beyond the first larval stage until the host pupates. Then the larva develops rapidly, maturing within 10 days. The mature larva leaves the host pupal case, drops to the ground, and pupates usually within 24 hr. Nine to 11 days later, the adult emerges. Very little information is available on the overwintering habits. The life history, habits, and rearing methods are outlined and important characters of the immature stages are illustrated and described.

Second Diapause in Spruce Budworm from Eastern Canada

1961 ◽  
Vol 93 (7) ◽  
pp. 594-602 ◽  
Author(s):  
George T. Harvey
Keyword(s):  
British Columbia ◽  
Experimental Analysis ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Fourth Instar ◽  
Eastern Canada ◽  
Low Incidence ◽  
One Year ◽  
Storage Times ◽  
Second Period

In eastern Canada larvae of the spruce budworm, Choristoneura fumiferana (Clem.), complete their development in one year, undergoing only one period of winter diapause in the second instar, whereas in certain parts of British Columbia, at high altitudes, two years are normally required for development, the larvae spending a second period of winter diapause in the fourth instar (3, 9). Among laboratory-reared eastern budworm there are a few individuals that enter a similar second diapause (7). The low incidence and somewhat irregular occurrence of this second diapause in eastern budworm, even in laboratory rearings, have hitherto made detailed studies almost impossible, but unusual storage times and treatments used recently in rearing experiments had the unexpected effect of increasing the incidence of this tvpe of behaviour to a level where experimental analysis became possible. This paper describes these larvae and their behaviour; an account of the effects of various conditions upon the incidence of second diapause will be presented later.

AN IMPROVED METHOD FOR PRODUCING LARGE NUMBERS OF SECOND-INSTAR SPRUCE BUDWORM LARVAE, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1972 ◽  
Vol 104 (12) ◽  
pp. 1955-1957 ◽  
Author(s):  
Dail Grisdale
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Immature Stages ◽  
Improved Method ◽  
Physical Conditions ◽  
Large Numbers

AbstractA method for weekly production in excess of 100,000 second-instar larvae of the spruce budworm, Choristoneura jumiferana (Clem.), is described. It depends on adherence to specific regimes of physical conditions and manipulation for the different immature stages. Standard, easily obtained utensils and materials are used in the rearing technique.

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.

Effects of Spruce Budworm Outbreaks on the Productivity and Stability of Balsam Fir Forests

1984 ◽  
Vol 60 (5) ◽  
pp. 273-279 ◽  
Author(s):  
David A. MacLean
Keyword(s):  
Tree Mortality ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Wood Production ◽  
Ecological Stability ◽  
Short Term ◽  
Eastern Canada ◽  
Feasible Method ◽  
Human Usage

Effects of spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks on the productivity and stability of forests in eastern Canada are reviewed and discussed. Defoliation results in reduced growth of trees, widespread tree mortality, and loss of wood production, and thereby causes major forest management problems. At present, the only feasible method for limiting damage and losses from budworm outbreaks over large areas is to apply chemical or biological insecticides periodically to kill larvae and protect the forest from defoliation and tree mortality. Although budworm outbreaks definitely disrupt the wood-producing capacity of forests (or the short-term "stability of forests for human usage"), in terms of overall ecological stability, outbreaks apparently act as a cycling mechanism that allows advance fir-spruce regeneration to succeed the fir-spruce overstory.

STUDIES ON DIPTEROUS PARASITES OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE): V. OMOTOMA FUMIFERANAE (TOT.) (DIPTERA: TACHINIDAE)

1957 ◽  
Vol 35 (5) ◽  
pp. 581-592 ◽  
Author(s):  
H. C. Coppel ◽  
B. C. Smith
Keyword(s):  
British Columbia ◽  
North America ◽  
Relative Humidity ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Immature Stages

Omoloma fumiferanae (Tot.), a parasite of a small number of Lepidoptera in North America and the most common of the native tachinid parasites of Choristoneura fumiferana (Clem.) in British Columbia, deposits macrotype eggs on the integument of the host. The time from oviposition (on a host about to pupate) to puparial formation was 8 to 12 days at 23 °C. and a relative humidity of 60%. Approximately 25% of puparia produce adults the same year. The fate of these adults is not known. The remainder of the puparia produce adults the following spring. Among the important characters for identifying the immature stages of O. fumiferanae are the buccopharyngeal apparatus and the anterior and posterior spiracles.

Biology and morphology of immature stages of Meteorus trachynotus Vier. (Hymenoptera: Braconidae)

1990 ◽  
Vol 68 (5) ◽  
pp. 1000-1004 ◽  
Author(s):  
J. C. Thireau ◽  
J. Régnière ◽  
C. Cloutier
Keyword(s):  
Average Duration ◽  
Choristoneura Fumiferana ◽  
Pupal Stage ◽  
Instar Larva ◽  
Immature Stages ◽  
Head Region ◽  
Larval Stages ◽  
First Instar ◽  
Immature Development ◽  
First Time

The immature stages of Meteorus trachynotus Vier., developing in larvae of Choristoneura fumiferana (Clem.), are described. The egg of M. trachynotus is of the stalked type. There are three larval stages. The first instar has a caudal appendage which stops growing in the second instar and is lost when the larva exits from the host in the third instar. Only the first and third instars have sclerotized structures. The head region of the first instar bears a pair of hooklike appendages which are described for the first time. Cephalic sclerites of the last instar larva of other species of Meteorus are compared with those of M. trachynotus. The average duration of immature development at 23 °C was 18 days, the egg stage lasted 3 days, the first, second, and third instars lasted 5, 2.5, and 2.5 days, respectively, and the pupal stage lasted 5 days.

The influence of forest composition and climate on outbreak characteristics of the spruce budworm in eastern Canada

2013 ◽  
Vol 43 (12) ◽  
pp. 1181-1195 ◽  
Author(s):  
David R. Gray
Keyword(s):  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Basal Area ◽  
Spruce Budworm ◽  
Climate Scenario ◽  
Forest Composition ◽  
Eastern Canada ◽  
The North ◽  
Average Change ◽  
Maximum Temperatures

The spruce budworm (Choristoneura fumiferana Clemens) is perhaps the single most important disturbance agent in Canada’s eastern forests. Climate and forest composition are dominant factors in spruce budworm outbreak dynamics through their direct influences on the pest, its natural enemies, and its hosts, and through their influence on the multitrophic interactions that are important in outbreak dynamics. A combination of four climate variables, three forest composition variables, and one location variable explained 60% of the multivariate variability in outbreak characteristics (duration and severity) in eastern Canada. Outbreak duration was most strongly influenced by April–May accumulation of degree-days; outbreak severity was most strongly influenced by the extreme maximum temperatures of April–May. The basal area of balsam fir had a stronger influence than that of black spruce on duration and on severity. Both outbreak characteristics declined in more northerly locations. Under a projected future (2011–2040) climate scenario the largest increases in outbreak duration and severity are predicted to occur on the Gaspé Peninsula and the north shore of the St. Lawrence River (Quebec). The largest decreases in duration and severity are predicted to occur in southern Ontario and along the Bay of Fundy in New Brunswick and Nova Scotia. The predicted average change in outbreak duration is around –1.3 years. The predicted average change in outbreak severity is only slightly different from zero (around –1.5% defoliation).

SUSCEPTIBILITY OF EARLY INSTARS OF SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) TO HETERORHABDITIS HELIOTHIDIS (NEMATODA: RHABDITIDAE)

1984 ◽  
Vol 116 (2) ◽  
pp. 285-287
Author(s):  
Jean R. Finney ◽  
Gordon F. Bennett
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Control Agent ◽  
Balsam Fir ◽  
Larval Instars ◽  
First Instar ◽  
Cryptic Habitats ◽  
Chemical Pesticides ◽  
Third Instar Larvae

Finney et al. (1982) reported on the susceptibility of the 4th to 6th larval instars and pupae of Choristoneura fumiferana (Clemens) to Heterorhabditis heliothidis (Khan, Brooks and Hirschmann). This report describes the susceptibility of the first three larval instars to the nematode. First-instar larvae search for suitable sites where they spin hibernacula in which they molt and overwinter as second-instar larvae. Most third-instar larvae burrow within the balsam fir buds. All these stages occupy cryptic habitats to which delivery of chemical pesticides is a problem. Rhabditid nematodes, which can actively seek out a target insect, may prove a more useful control agent under these circumstances.

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