The effect of ingested benzoylphenylurea on the ultrastructure of the cuticle deposited during the last larval instar of Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae)

1987 ◽  
Vol 65 (11) ◽  
pp. 2715-2723 ◽  
Author(s):  
Jean Percy-Cunningham ◽  
Diane Nicholson ◽  
Arthur Retnakaran
Keyword(s):  
Choristoneura Fumiferana ◽  
Larval Instar ◽  
Amorphous Material ◽  
Spruce Budworm ◽  
Amino Sugar ◽  
Epidermal Cells ◽  
Protein Component ◽  
Ultrastructural Changes ◽  
Sublethal Dose

The sequential ultrastructural changes induced by the ingestion of a sublethal dose of a benzoylphenylurea, chlorfluazuron, were investigated in sixth-instar larvae of the spruce budworm, Choristoneura fumiferana. The 4-day-old, postecdysis larvae showed the most profound ultrastructural effects. The newly formed endocuticle showed an absence of lamellae, indicating the lack of formation of chitin microfibrils. Vacuolated and fibrous areas containing an amorphous material, possibly proteinaceous, were observed in the region where lamellae would normally be present. The epidermal cells had microvilli with swollen and rounded tips. These cells also contained oval vesicles containing granular amorphous material. The in vivo inhibition of chitin deposition by this benzoylphenylurea was readily apparent. It is suggested that the amorphous material observed in the zone where chitin was lacking is the protein component of the glycoprotein chitin. It is possible that the benzoylphenylurea inhibits the assembly of the amino sugar with the protein to form microfibrils.

Parasitism of Spruce Budworm by Glypta and Apanteles at Different Crown Heights in Montana

1961 ◽  
Vol 93 (3) ◽  
pp. 222-228 ◽  
Author(s):  
Harold R. Dodge
Keyword(s):  
Choristoneura Fumiferana ◽  
Larval Instar ◽  
Spruce Budworm

Glypta fumifermae (Vier.) (Ichneumonidae) and Apanteles fumiferanae Vier. (Braconidae) are two of the most common parasites of immature larvae of the spruce budworm, Choristoneura fumiferana (Clem.). Females parasitize the minute host larvae in the fall. Their eggs or larvae lie dormant within the hibernating host larvae, and then resume development in the spring, when the spruce budworm larva breaks hibernation and commences to feed. The budworm host is killed by Apanteles usually when it is in the fifth larval instar or by the Glypta when it is in the sixth instar.

THEORETICAL OPTIMIZATION OF BACILLUS THURINGIENSIS BERLINER FOR CONTROL OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEM. (LEPIDOPTERA: TORTRICIDAE): ESTIMATES OF LETHAL AND SUBLETHAL DOSE REQUIREMENTS, PRODUCT POTENCY, AND EFFECTIVE DROPLET SIZES

1993 ◽  
Vol 125 (3) ◽  
pp. 473-478 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Nicholas J. Payne
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Sublethal Dose ◽  
Current Application ◽  
Feeding Inhibition ◽  
Eastern Spruce Budworm ◽  
Force Feeding ◽  
Droplet Sizes

AbstractWe present calculations of droplet sizes and product potencies that are theoretically required to deliver a lethal dose of Bacillus thuringiensis in one droplet to larvae of the eastern spruce budworm in aerial spray applications. The calculations are based on estimates of the dose required for 50% and 95% mortality [4.3 and 26.9 International Units (IU), respectively] and of the lowest dose that caused discernable feeding inhibition (0.5 IU) in force-feeding assays with sixth-instar larvae. For products containing 12.7–16.9 billion IU (BIU) per litre, the most widely used potency range, a 150- to 160-μm droplet is needed to deliver an LD95 and an 80- to 90-μm droplet to deliver an LD50, whereas droplets down to 40 μm are expected to cause extensive feeding inhibition. Our calculations suggest that current application prescriptions result in the delivery of a marginally effective dose to the target foliage and that budworm larvae have to ingest multiple droplets to obtain a lethal dose, a process that is thought to contribute to inconsistent spray efficacy. We predict that dose acquisition can be maximized by increasing product potency to 95 BIU/L, which would enable larvae to acquire a lethal dose by ingestion of only one or two droplets in the size range that is most commonly encountered on coniferous foliage (≤ 80 µm) after aerial application.

HORMONAL INDUCTION OF SUPERNUMERARY INSTARS IN THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1973 ◽  
Vol 105 (3) ◽  
pp. 459-461 ◽  
Author(s):  
Arthur Retnakaran
Keyword(s):  
Juvenile Hormone ◽  
Choristoneura Fumiferana ◽  
Larval Instar ◽  
Spruce Budworm ◽  
Hormone Analogue ◽  
Larval Instars ◽  
Juvenile Hormone Analogue ◽  
Hormonal Induction

AbstractInduction of supernumerary larval instars in the spruce budworm, Choristoneura fumiferana Clemens, by applying ZR-515, a potent juvenile hormone analogue, is explained in terms of larval differentiation. Application to the early sixth instar where structures are relatively indeterminate results in the formation of a supernumerary larval instar, whereas treatment of the late-larva wherein many structures are committed to differentiate towards the pupa, results in a larval–pupal mosaic.

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Morphometric Analysis of the Hepatocytes from Fish Exposed to Arsenic

1976 ◽  
Vol 34 ◽  
pp. 282-283
Author(s):  
Elsie M. B. Sorensen
Keyword(s):  
Morphometric Analysis ◽  
Arsenic Concentration ◽  
Ultrastructural Changes ◽  
Sodium Arsenate ◽  
Lepomis Cyanellus ◽  
Mammalian Counterpart ◽  
Intracellular Changes ◽  
Green Sunfish ◽  
Organic Pesticides

The detoxification capacity of the liver is well documented for a variety of substances including ethanol, organic pesticides, drugs, and metals. The piscean liver, although less enzymatically active than the mammalian counterpart (1), contains endoplasmic reticulum with an impressive repertoire of oxidizing, reducing, and conjugating abilities (2). Histopathologic changes are kncwn to occur in fish hepatocytes following in vivo exposure to arsenic (3); however, ultrastructural changes have not been reported. This study involved the morphometric analysis of intracellular changes in fish parynchymal hepatocytes and correlation with arsenic concentration in the liver.Green sunfish (Lepomis cyanellus, R.) were exposed to 0, 30, or 60 ppm arsenic (as sodium arsenate) at 20°C for 1, 2, or 3 week intervals before removal of livers for quantification of the arsenic burden (using neutron activation analysis) and morphometric analysis of ultrastructural alterations. Livers were cut into 1 mm cubes for fixation, dehydration, and embedding.

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.

Increased susceptibility of purinergic receptor-deficient mice to lung infection withPseudomonasaeruginosa

2005 ◽  
Vol 289 (5) ◽  
pp. L890-L895 ◽  
Author(s):  
Cara Geary ◽  
Henry Akinbi ◽  
Tom Korfhagen ◽  
Jean-Etienne Fabre ◽  
Richard Boucher ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Purinergic Receptors ◽  
Tissue Injury ◽  
Purinergic Receptor ◽  
Intratracheal Instillation ◽  
Lavage Fluid ◽  
Sublethal Dose ◽  
Wild Type ◽  
Double Knockout

Purinergic receptors are expressed throughout the respiratory system in diverse cell types. The efficiency of mucus clearance in the airways, the cascade leading to tissue injury, and inflammation are modulated by autocrine/paracrine release of nucleotides and signaling by purinergic receptors. We assessed the role of purinergic receptors in innate host defense of the lung in vivo by infecting mice deficient in P2Y1, P2Y2, or both receptors with intratracheal instillation of Pseudomonas aeruginosa. After P. aeruginosa challenge, all double knockout (P2Y1/P2Y2−/−) mice succumbed within 30 h of challenge, whereas 85% of the wild-type mice survived. Thirty-three percent of wild-type mice survived beyond 96 h. Single knockout mice, P2Y1−/−, or P2Y2−/−, exhibited intermediate survivals. Twenty-four hours following intratracheal instillation of a sublethal dose of P. aeruginosa, the level of total protein in bronchoalveolar lavage fluid was 1.8-fold higher in double knockout than in wild-type mice ( P < 0.04). Total cell count in bronchoalveolar lavage fluids at 4 h and levels of IL-6 and macrophage inflammatory protein-2 in lung homogenates at 24 h postchallenge were significantly reduced in P2Y1/P2Y2−/− mice relative to wild-type mice. These findings suggest that purinergic receptors exert a protective role against infection of the lungs by P. aeruginosa by decreasing protein leak and enhancing proinflammatory cytokine response.

Epithelial–mesenchymal interactions allow for epidermal cells to display an in vivo-like phenotype in vitro

2005 ◽  
Vol 73 (2-3) ◽  
pp. 79-87 ◽  
Author(s):  
Eduardo Mitrani ◽  
Guy Nadel ◽  
Eilat Hasson ◽  
Esther Harari ◽  
Yael Shimoni
Keyword(s):  
Epidermal Cells
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