Recherche d'une Méthode d'Utilisation du Bacillus thuringiensis pour Combattre les Insectes Forestiers

1964 ◽  
Vol 96 (1-2) ◽  
pp. 152-152
Author(s):  
W. A. Smirnoff
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana

Parmi les espèces de bactéries comprises dans le groupe “cereus”, il en existe une très pathogène pour certaines espèces d'insectes, c'est le Bacillus thuringiensis Berliner. Ce bacille produit des spores et des cristaux toxiques dans la cellule et excrète diverses substances toxiques dans son milieu de culture. L'action du B. thuringiensis varie avec les espèces d'insectes; chez certaines il provoque une septicémie typique, chez d'autres il cause une intoxication, alors que quelques espèces sont réfractaires à ses attaques. Depuis quelques années notre laboratoire envisage la possibilité d'utiliser le B. thuringiensis et d'autres espèces proche parentes dans la lutte à certains insectes forestiers fort nuisibles tels que la tordeuse des bourgeons de l'épinette (Choristoneura fumiferana (Clem.)), l'un des plus graves ravageurs des forês de conifères dans l'est de l'Amérique du Nord. En laboratoire avec une suspension contenant 200 gr. du pathogène par gallon d'eau, toutes les chenilles en expérience sont mortes de septicémie typique dans l'espace de 8 jours. Lors d'expériences conduites dans un peuplement hébergeant une forte population de I'insecte et dans des conditions climatiques optimales, 84 pour 100 de la population larvaire fut détruite en dedans de 24 jours après l'application d'une suspension contenant 80 gr. du pathogène par gallon d'eau. Ces premiers résultats nous incitérent à rechercher une lignée du B. thuringiensis plus pathogène pour le C. fumiferana surtout aux basses températures, et capable de résister à l'action bactéricide et bactériostatique de certaines substances produites par le feuillage du sapin et de l'épinette.

LONG TERM STUDY OF THE EFFECTIVENESS OF AERIAL APPLICATION OF BACILLUS THURINGIENSIS – ACEPHATE COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Population Densities ◽  
Long Term Study

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.

EFFECT OF TEMPERATURE ON THE PATHOGENESIS OF BACILLUS THURINGIENSIS BERLINER IN LARVAE OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEM. (LEPIDOPTERA: TORTRICIDAE)

1994 ◽  
Vol 126 (4) ◽  
pp. 1061-1065 ◽  
Author(s):  
Kees van Frankenhuyzen
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Growth ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Effect Of Temperature ◽  
Vegetative Cells ◽  
Time Required ◽  
Peak Abundance

AbstractThe relationship between temperature and pathogenesis of Bacillus thuringiensis Berliner var. kurstaki in infected larvae of the eastern spruce budworm, Choristoneura fumiferana Clem., was investigated to determine if more rapid death of larvae with an increase in temperature could be accounted for by enhanced bacterial growth. Cumulative mortality of larvae force-fed with a lethal dose of HD-1-S-1980 peaked within 2 days at 25 °C, 3 days at 19 °C, 7 days at 16 °C, and 21 days at 13 °C. The progress of bacterial growth in the larvae was followed from spore germination to cell lysis, and was completed within 4 days at 25 °C, 6 days at 22 °C, 12 days at 19 °C, 14 days at 16 °C, and > 28 days at 13 °C. Peak abundance of vegetative cells in the larvae was observed after 1 day at 25 °C, 2 days at 22 °C, 3 days at 19 °C, 7 days at 16 °C, and 21 days at 13 °C, and thus coincided almost exactly with the time required for maximum larval mortality. This correlation suggests that the observed effect of temperature on progression of larval mortality was due to its effect on the proliferation of vegetative cells in the infected larvae, and that bacterial septicemia makes an important contribution to death.

RELATIVE POTENCIES OF 50 ISOLATES OF BACILLUS THURINGIENSIS FOR LARVAE OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1983 ◽  
Vol 115 (7) ◽  
pp. 815-822 ◽  
Author(s):  
O. N. Morris ◽  
A. Moore
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Larval Growth ◽  
Spruce Budworm ◽  
Relative Potencies

AbstractFifty Bacillus thuringiensis (B.t.) isolates representing K-1, galleriae, K-73, thuringiensis, aizawai, dendrolimus, tolworthi, kenyae, darmstadiensis, alesti, and entomocidus crystal antigen types were bioassayed against fifth-instar spruce budworm, Choristoneura fumiferana (Clem.), larvae. In addition, larvae reared on diet with and without aureomycin were tested for their susceptibility to B.t. The data indicated no significant differences in susceptibility to B.t. among insects reared on aureomycin or on aureomycin-free diet, but differences were evident in larval growth and mortality among untreated controls. None of the 50 isolates bioassayed was any more toxic to the budworm than is the strain used at present in commercial preparations of B. thuringiensis.

FORECASTING THE EFFICACY OF OPERATIONAL BACILLUS THURINGIENSIS BERLINER APPLICATIONS AGAINST SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEMENS (LEPIDOPTERA: TORTRICIDAE), USING DOSE INGESTION DATA: INITIAL MODELS

1992 ◽  
Vol 124 (6) ◽  
pp. 1101-1113 ◽  
Author(s):  
Richard A. Fleming ◽  
Kees van Frankenhuyzen
Keyword(s):  
Bacillus Thuringiensis ◽  
Population Density ◽  
Choristoneura Fumiferana ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Initial Application ◽  
Eastern Spruce Budworm ◽  
Population Reduction ◽  
Support Tools ◽  
Image Position

AbstractSingle aerial applications of Bacillus thuringiensis Berliner (Bt) to control infestations of the eastern spruce budworm (Choristoneura fumiferana Clemens) have had varied operational success. Double applications are too expensive for general use, but might prove useful if directed to areas where the initial application was unsuccessful. This requires forecasts of the efficacy of the initial application in operational spray blocks within 4–5 days.Data were collected in 30 spray blocks in 1989 in a feasibility study to determine if such forecasts of spray efficacy could be made from the prespray budworm population density, N0, and from the proportion of the population that had ingested a lethal dose Bt within 2 days of application, M. A mathematical model forecasting the postspray budworm population density, NF, was derived from population-dynamic considerations and fitted (r2 = 0.48, p < 0.0001):The proportion of current foliage defoliated, D, depended (r = 0.81) on N0 and on whether the block was sprayed (I = 0) or not (I = 1):Only one measure of defoliation involved M in any statistically significant way. The predicted (from values of N0) proportion of defoliation prevented by Bt application, dD, was weakly (r2 = 0.25, p = 0.002) related to M:The large proportion of the variation in efficacy that remains unexplained by the models involving M limits the operational utility of this approach as it now stands for specific sites. The potential for further development of these models as decision support tools for fairly large spray blocks is discussed in terms of improving the sampling plan and including additional predictor variables.Methods are also presented that reduce bias in calculations of population reduction (Abbott 1925) and foliage protection when data are available from few control and many treatment blocks.

CONFIRMATIONS EXPERIMENTALES DU POTENTIEL DU COMPLEXE BACILLUS THURINGIENSIS ET CHITINASE POUR LA REPRESSION DE LA TORDEUSE DES BOURGEONS DE L’EPINETTE, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1977 ◽  
Vol 109 (3) ◽  
pp. 351-358 ◽  
Author(s):  
W.A. Smirnoff
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Choristoneura Fumiferana

RésuméDes études intensives et systématiques qui ont été conduites en laboratoire en tenant compte de l’âge et de l’état physiologique de l’insecte, ainsi que des conditions de température, ont démontré que Bacillus thuringiensis Berliner non cristallogène ainsi que Bacillus cereus Frankland et Frankland étaient aussi pathogènes pour les larves de Choristoneura fumiferana Clemens que la souche de B. thuringiensis cristallogène testé. Ainsi, à 20°C, B. thuringiensis var. kurstaki provoquait chez les larves de 3e âge de C. fumiferana une lente septicémie causant la mortalité de 90% des larves en 27 jours. Dans des conditions expérimentales identiques, une souche de B. thuringiensis non cristallogène (n° 17) et deux souches de B. cereus entomopathogènes isolées chez C. fumiferana et chez un tachinidé causaient également une lente septicémie chez C. fumiferana et provoquaient 90% de mortalité des larves de 3e âge après une période de 30 à 32 jours.Les expériences ont démontré par ailleurs que l’addition de quantités minimes de chitinase, soit l’équivalent de 10,000 UN/ha augmentait considérablement l’efficacité des préparations commerciales de B. thuringiensis contre C. fumiferana. Ainsi, la préparation bacillaire Sandoz-Wander (E.U.) 26B, dispersée à raison de 16.8 × 109 IU/ha, n’entraînait pas plus de 80% de mortalité des larves de 3e et de 4e âges après 30 jours, tandis que, avec l’addition de chitinase N.B.C., la mortalité était de 100% entre 9 et 27 jours selon les conditions expérimentales. Des résultats similaires ont été obtenus avec la préparation Dipel 36B; un taux de 100% de mortalité chez les larves de 3e âge a été atteint en 9 jours avec l’addition de chitinase et en 24 jours sans l’apport de cet enzyme. Dans un programme de lutte contre C. fumiferana à l’aide de B. thuringiensis, l’addition de chitinase s’avère donc essentielle.

AN IMPROVED TECHNIQUE FOR DOSING LARVAE OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE), WITH MEASURED QUANTITIES OF BACILLUS THURINGIENSIS VAR. KURSTAKI

1982 ◽  
Vol 114 (1) ◽  
pp. 89-91 ◽  
Author(s):  
A. Moore ◽  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Artificial Diet ◽  
Antimicrobial Agents ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Test Sample ◽  
Serial Dilution ◽  
Artificial Diets ◽  
Improved Technique

Bioassays of Bacillus thuringiensis (Bt.) are commonly performed by applying a serial dilution of the test sample to either foliage or artificial diet (Burges and Thompson 1971). In these assays the ingested dose is not measured directly, but is assumed to be proportional to the concentration of the sample applied to the diet. This assumption is valid only if the total amount of food ingested during the experiment is the same at all dosage levels. However, this assumption may not be true because Bt. inhibits feeding of some lepidoptera larvae (Burges and Thompson 1971). Furthermore, artificial diets usually contain nutrients and possibly antimicrobial agents which may interact with Bt.

Sublethal effects of Bacillus thuringiensis on the spruce budworm, Choristoneura fumiferana

1997 ◽  
Vol 83 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Anita Pedersen ◽  
John Dedes ◽  
Debbie Gauthier ◽  
Kees Frankenhuyzen
Keyword(s):  
Bacillus Thuringiensis ◽  
Sublethal Effects ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm
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