PTEROTHORACIC MUSCULATURE OF THE ADULT MALE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1971 ◽  
Vol 103 (1) ◽  
pp. 1-12 ◽  
Author(s):  
B. K. Mitchell ◽  
W. D. Seabrook

AbstractThe musculature of the pterothorax of the adult male Choristoneura fumiferana (Clem.) is described in detail and the arrangement of muscles is shown to correspond closely to other lepidopterans. A comparison with the general plan of the alate segment is also attempted.

1971 ◽  
Vol 103 (12) ◽  
pp. 1753-1756 ◽  
Author(s):  
Arthur Retnakaran

AbstractTopical application of thiotepa on the adult male spruce budworm, Choristoneura fumiferana Clemens, at a concentration of 10 μg/insect resulted in 100% sterility. Unlike metepa, thiotepa did not have any apparent adverse effects on the competency of the sperms. Large numbers of male moths can be sterilized by allowing them to walk for 30 min on filter paper treated with a 2.5% solution of thiotepa in a 3:1 mixture of acetone and diffusion pump oil.


1970 ◽  
Vol 102 (5) ◽  
pp. 627-636 ◽  
Author(s):  
B. K. Mitchell ◽  
W. D. Seabrook

AbstractThe musculature of the prothorax and the prothoracic coxa of the adult male Choristoneura fumiferana (Clem.) is described in detail and is compared with three other families of the Lepidoptera.


1983 ◽  
Vol 115 (11) ◽  
pp. 1437-1443 ◽  
Author(s):  
S. B. Ramaswamy ◽  
R. T. Cardé ◽  
J. A. Witter

AbstractLarval densities and catch of adult male Choristoneura fumiferana (Clemens) in pheromone-baited covered funnel traps in the same year were highly correlated. Such traps avoid saturation problems associated with conventional sticky traps. Release of marked males resulted in recapture rates of up to 21% in covered funnel traps. The findings suggest that non-saturating pheromone-baited traps could be used to monitor population densities and trends of the spruce budworm.


1987 ◽  
Vol 22 (3) ◽  
pp. 193-200 ◽  
Author(s):  
Linda Ellis White ◽  
W. D. Seabrook

The neuromorphology of the brain and suboesophageal ganglion (SOG) of the adult male spruce budworm, Choristoneura fumiferana (Clemens), is described and compared with information in the existing literature on adult Lepidoptera. The brain, SOG, and connecting nerves are illustrated. Protocerebral nerves include two pairs to the corpora cardiaca as well as optic nerves and ocellar pedicels. One pair of antennal nerves innervate the deuto-cerebrum and the tritocerebrum is innervated by one pair of labrofontalis nerves. Five pairs of nerves arise from the SOG: the mandibular, maxillary, labial, and two pairs of cervical nerves.


Author(s):  
Marc Rhainds ◽  
Ian DeMerchant ◽  
Pierre Therrien

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.


1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais

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.


1987 ◽  
Vol 119 (3) ◽  
pp. 251-263 ◽  
Author(s):  
S.M. Smith ◽  
M. Hubbes ◽  
J.R. Carrow

AbstractDuring 1982 and 1984, ground releases of Trichogramma minutum Riley were assessed for control of the spruce budworm, Choristoneura fumiferana (Clemens), on 12- to 20-year-old, white spruce stands in northern Ontario. Maximum parasitism of susceptible egg masses was 16 and 87% following the release of 480 000 and 12 million female T. minutum per hectare, respectively. Releases at intervals of 1 week maintained parasitism of susceptible egg masses at constant levels throughout the oviposition period of spruce budworm. When parasitism of susceptible egg masses was maintained above 78.2% during the ovipositional period, total egg mass parasitism averaged 58.0% and resulted in an 80.3% reduction of overwintering 2nd-instar larvae. The optimal strategy for reducing spruce budworm was two releases of T. minutum at an interval of 1 week in the ovipositional period. This allowed a second generation of parasitoids to emerge from the spruce budworm eggs that were more efficient in maintaining high levels of parasitism than those emerging from the standard rearing host. Natural parasitism of spruce budworm egg masses was less than 4% and there was no carryover of parasitism in the years following inundative release. The rate of T. minutum release necessary to achieve effective mortality of spruce budworm during outbreak populations is discussed briefly.


1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.


1997 ◽  
Vol 129 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Robert K. Lawrence ◽  
William J. Mattson ◽  
Robert A. Haack

AbstractSynchrony of insect and host tree phenologies has often been suggested as an important factor influencing the susceptibility of white spruce, Picea glauca (Moench) Voss, and other hosts to the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). We evaluated this hypothesis by caging several cohorts of spruce budworm larvae on three white spruce populations at different phenological stages of the host trees, and then comparing budworm performance with host phenology and variation of 13 foliar traits. The beginning of the phenological window of susceptibility in white spruce occurs several weeks prior to budbreak, and the end of the window is sharply defined by the end of shoot growth. Performance was high for the earliest budworm cohorts that we tested. These larvae began feeding 3–4 weeks prior to budbreak and completed their larval development prior to the end of shoot elongation. Optimal synchrony occurred when emergence preceded budbreak by about 2 weeks. Larval survival was greater than 60% for individuals starting development 1–3 weeks prior to budbreak, but decreased to less than 10% for those starting development 2 or more weeks after budbreak and thus completing development after shoot elongation ceased. High performance by the budworm was most strongly correlated with high levels of foliar nitrogen, phosphorous, potassium, copper, sugars, and water and low levels of foliar calcium, phenolics, and toughness. These results suggest that advancing the usual phenological window of white spruce (i.e. advancing budbreak prior to larval emergence) or retarding budworm phenology can have a large negative effect on the spruce budworm’s population dynamics.


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