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1.
The efficacy of the commercial product Dipel 2X (Bacillus thuringiensis var.kurstaki), was assessed as a biological control means of the cotton leaf wormSpodoptera littoralis attacking clover cultivations (Trifolium alexandrinum) in Egypt. Field experiments using the biological agent were carried out in two localities as compared with the conventional chemical insecticide lannate. The percentage of reduction in the larval population increased at higher doses ofB. t. and the infestation levels reached very low levels, almost similar to those obtained after using lannate. The yield of the first cut of clover was estimated. The data obtained indicate that the yield significantly increased after treatment with eitherB. t. or lannate. In Menoufia, the yield was significantly higher after two successive spray applications withB. t. at 750 g/f compared to that obtained withB. t. when used at 500 g/f. In Giza Governorate, the yield was slightly higher after a single treatment withB. t. at 500 g/f as compared with lannate.  相似文献   

2.
Agrotis ypsilon andSpodoptera littoralis can be successfully controlled on various field crops usingBacillus thuringiensis (Dipel 2X) baits and sprays. Baits based on the pathogen at 200–250 g/Feddan, scored the best efficacy againstA. ypsilon in clover fields followed by potato, tomato, and cotton cultivations. Addition of some chemical additives (inorganic salts) toB. thuringiensis bait formulations greatly enhanced its potency. This was associated with an obvious increase in the yield of clover, potato and tomato crops; calcium oxide showed to be highly afficient in this respect. Sprays of Dipel 2X were also found as affective as lannate in controllingS. littoralis on clover cultivations.
Zusammenfassung Die Untersuchungen ergaben, daßAgrotis ypsilon undSpodoptera littoralis an verschiedenen Feldfrüchten erfolgreich mitBacillus thuringiensis (Dipel 2X) als Köder oder Sprühmittel bekämpft werden können. Die Köder auf der Grundlage von 200–250 gBacillus/Feddan erzielten die besten Ergebnisse gegenA. ypsilon auf Kleefeldern, gefolgt von Kartoffel, Tomate und Baumwolle. Die Beimengung von chemischen Zusatzmitteln (anorganische Salze) zu denBacillus-Ködern erhöhte die Wirksamkeit beträchtlich. Daraus resultierte eine auffallende Steigerung der Klee-, Kartoffel- und Tomatenernte. Dabei war Kaliumoxid das wirksamste Zusatzmittel. Das Sprühen mit Dipel 2X erwies sich in Kleefeldern als ebenso wirksam wie die Anwendung des chemischen Pestizids Lannate.

With 4 tables  相似文献   

3.
The calculated percentage of droplets deposition ofBacillus thuringiensis var.kurstaki HD-1 Dipel 2X on the foliage of soybean plants in relation to the sensitive “Ciba Geigy” papers showed to be the highest (92.4%) after ground spray application, compared to an average of 67.4, 85.8 and 89.3% following aerial application of the same preparation in spray volumes of 10, 20 and 30 l/F, respectively. Aerial application ofB. t. showed to be more effective during the first 3 days after spraying soybean cultivations and the mortality ofSpodoptera littoralis larvae varied between 36.9–67.2% in correlation to the spray volume. The volume achieving the highest and significant suppression of infestation was 20 l/F. On the other hand, the yield of soybeans obtained from plots receiving a spray volume of 30 l/F was higher compared to plots sprayed with a volume of 20 or 10 l/F, but with no significant difference when compared to those plots receiving ground spray application.  相似文献   

4.
Zusammenfassung Die Reaktion vonAgrotis ypsilon Rott.,Laphygma exigua Hbn. undSpodoptera littoralis Boisd. aufBacillus entomocidus subtoxicus, Biospor, bzw.B. thuringiensis thuringiensis 2172 wurde bestimmt, wobei drei verschiedene Arten von Nahrung gereicht wurden und zwei verschiedene Arten der Behandlung durchgeführt wurden. Bei der Aufnahme behandelten Futters war die Sterblichkeit bedeutend herabgesetzt, wenn Blätter vonRicinus medicinalis als Nahrung gegeben wurden. Die Sterblichkeit der beiden anderen Gruppen, bei denenGrossypium barbadense undTrifolium alexandrinum als Nahrung verwendet wurde, wich nicht merklich voneinander ab. Bei den 3 Insektenarten war die Sterblichkeit bei der oralen Behandlung auffallend höher als bei der Injektion derselben Menge direkt in das Haemocoel.
Summary The response ofAgrotis ypsilon Rott.,Laphygma exigua Hbn. andSpodoptera littoralis Boisd. toBacillus entomocidus subtoxicus, biospore andB. thuringiensis thuringiensis 2172 respectively was evaluated, using 3 different diets for voluntary ingestion and 2 other different modes of treatment. In the voluntary ingestion tests the mortality was markedly reduced, when foliage ofRicinus medicinalis was used as diet. The mortalities in the other two groups, whereGossypium barbadense andTrifolium alexandrinum were used as diet, did not differ significantly from each other. In the three insect species the mortality in oral treatments was markedly higher than that resulting from injecting the same dose directly into the hemocoele.
  相似文献   

5.
The effective threshold rate of application of Dipel 2X was 250g/f. Incorporation of some chemical additives such as calcium sulphate (CaSO4) or calcium oxide (CaO) significantly potentiated the effectiveness of Dipel 2X on larval population. The addition of calcium carbonate (CaCO3) and zinc sulphate (ZnSO4) to Dipel 2X greatly reduced the larval population and led to a significant increase in the yield of some vegetable crops. Dipel 2X baits at 250g/f were almost as effective as the chemical insecticide Hostathion when used at 1.5l/f in controllingA. ypsilon larvae attacking vegetable crops. Control of the greasy cutwormAgrotis ypsilon population was better achieved when the biological control agent Dipel 2X was used as baits.  相似文献   

6.
The Egyptian cotton leafworm,Spodoptera littoralis Boisd., is the main important pest of alfalfa in Israel. Population levels of other pests usually do not reach the economic threshold. Nine chemical insecticide applications (7 spray applications and 2 granular fluorosilicate baits) were required to controlS. littoralis during the season of 1984 (in which infestation level was high) whereas only 5 applications of aBacillus thuringiensis var.entomocidus (Bte) preparation (3 sprays and 2 baits) produced the same effect. During 1983 and 1985 pest populations were moderate and only 6 chemical pesticide applications were required. A bait ofBte on wheat bran, Coax®, developed in the present study was effective in the control of large larvae (instars 4–6). Hay yields of fields treated withBte were similar to the yields of a conventionally treated field. The best control of large larvae was obtained by applying the bait preparation under the wind row during the alfalfa cutting.  相似文献   

7.
Field tests were conducted to determine the effectiveness of wheat bran baits based onSteinernema feltiae compared to the pathogenBacillus thuringiensis and the organophosphorus compound hostathion againstAgrotis ipsilon infesting Okra,Hibiscus esculentis cultivations. Significant larval reduction was observed in all treated plots after application with a significant increase in the yield compared to the control plots. The yield was significantly affected by varying the number of IJS of the entomogenous nematode in the baits.With one table  相似文献   

8.
Zusammenfassung Die Virulenz von 13 Bacilluspr?paraten (2 Handelspr?parate vonBacillus thuringiensis var,thuringiensis Berliner und 11 Laboratoriums-Pr?parate von verschiedenen Arten und Variet?ten) gegen 3 ?gyptische Noctuiden (Agrotis ypsilon Rott.,Laphygma exigua Hbn. undProdenia litura Fab.) wurden untersucht. 50 Raupen von jeder Art (6–7 Tage alt) wurden für jede Behandlung und die Kontrolle verwendet (einen Tag auf behandeltes Laub vonTrifolium alexandrinum gesetzt). Die Resultate ergaben, da?Laphygma in 9 F?llen sehr empfindlich ist, wobei sich ein deutlicher Unterschied zu den beiden anderen Arten ergab. In 7 dieser F?lle folgte aufLaphygma Prodenia und in 2 F?lleAgrotis. Besonders wirksame Pr?parate waren: Biospor 2802 gegenLaphygma, Bacillus thuringiensis var.thuringiensis 2172 gegenProdenia undB. entomocidus var.subtoxicus 1179 gegenAgiotis. In den meisten F?llen wurde kein direkter Zusammenhang zwischen Virulenz und Zahl der lebenden Sporen gefunden.
Summary The virulence of 13 Bacillus preparations (2 commercial formulations ofBacillus thuringiensis var.thuringiensis Berliner and 11 laboratory preparations of different varieties and species) on 3 Egyptian noctuids (Agrotis ypsilon Rott.,Laphygma exigua Hbn. andProdenia litura Fab.) was tested. Fifty larvae of each species (6–7 days-old) were used for each treatment and for the control (one day voluntary ingestion on foliage ofTrifolium alexandrinum). Results revealed thatLaphygma is most susceptible in 9 cases with marked difference between it and both other species. In 7 of these casesLaphygma was followed byProdenia and in 2 cases byAgrotis. Most virulent preparations were: Biospore 2802 againstLaphygma, Bacillus thuringiensis var.thuringiensis 2172 againstProdenia andB. entomocidus var.subtoxicus 1179 againstAgrotis. In most cases no direct relationship was observed between virulence and number of viable spores in dose.

Die Autoren sind zu Dank verpflichtet Herrn Dr. A. Burgerjon, Station des Recherches de Lutte Biologique (La Miniere), Herrn Dr. G. Benz ETH-Entomological Institute (Zürich), Herrn J. Wolf, Department of Agriculture (Leeds) und der N. R. R. L. (Illinois) für die Beschaffung der Bakterien-Pr?parate, die in vorliegender Arbeit verwendet wurden.  相似文献   

9.
Field applications usingBacillus thuringiensis (Dipel 2 X) againstSpodoptera exigua infesting corn and sunflower cultivations were carried out in two different localities in Egypt. The percentage of infested corn plants decreased to 2.5%, seven days after treatment with Dipel 2x, (250 g/fed) and the yield was significantly increased compared with untreated plots. The carbamate insecticide (Lannate) at 300 g/fed caused complete kill to the larvae and the highest yield was obtained. Application of Lannate, Dipel (250 g) or a combination of both (150 g/each/fed) caused a high reduction of the larvae existing in sunflower after seven days from application, while Dipel at 200 g/fed gave a lower effect. Ten days after application, the number of larvae and infested plants increased significantly in plots treated with Lannate alone, while plots treated with either Dipel (250 g) or Dipel combined with Lannate (150 g/each) still maintained a lower infestation. The estimated yield showed the highest increase in plots treated with Lannate followed by Dipel (250 g) and then a combination of both.  相似文献   

10.
Shellac was evaluated as radiation protection for the bacteriumBacillus thuringiensis var.entomocidus againstSpodoptera littoralis larvae. Shellac provided excellent protection toB. thuringiensis. The efficacy of shellac in the protection of entomocidal activity ofB. thuringiensis var.entomocidus against UV irradiation has been studied. Results obtained by the absorbtion and the bioassay of residual entomocidal activity ofB. thuringiensis var.entomocidus after exposure to UV irradiation showed that shellac is an excellent photoprotective agent.  相似文献   

11.
Field tests were conducted to determine the effectiveness of wheat-brain baits based onBacillus thuringiensis var.kurstaki HD-1 (dipel 2x) compared to the organophosphorous insecticide Hostathion against the greasy cutwormAgrotis ypsilon infestations on horse bean (Vicia fabae) cultivations. Significant larval reductions were observed in all treated plots after one application with a significant increase in the yield (1.45–1.60 folds) compared to the control plots. The yield was not obviously affected by varying the dose of dipel in the bait between 150–250 g/feddan. The addition of the adjuvant potassium carbonate to the dipel bait caused a significant larval reduction, 10 days after application and showed to be as efficient as baits based on Hostathion.  相似文献   

12.
On the distribution of Bacillus thuringiensis Berl. and some Sporozoon diseases of store damaging Lepidoptera in the Kosova region, Yugoslavia The studies concerning the incidence and distribution ofBacillus thuringiensis Berl. and various Sporozoa, such asMattesia dispora Naville (Weiser, 1954),Nosema heterosporum Kellen & Lindengren,Telochania ephestiae Mattes andAdelina mesnili Perez, as well as the quantitative and qualitative relationships of both groups of pathogens to various store product destroying Lepidoptera, were carried out with specimens found in 57 watermills at 22 localities in the are of Kosova, Yugoslavia.A total of 3065 dead and living larvae ofEphestia kühniella infected withBacillus thuringiensis and Sporozoa were examined. Other larvae also examined after infection withB. thuringiensis included specimens ofE. elutella, Plodia interpunctella, Plutella maculipennis andPyralis farinalis.Regarding the relationships of the overall intensity of infection of theE. kühniella larvae to the portion of the insects examined (table 2), the following habitats displayed the highest percentage: Hulaj and Tekuli 100%, Prizreni 86% and Isniqi 80%. The intensity of the larvae infected withB. thuringiensis was highest at Istogu 35%, Radavci 33% and Isniqi 32%. The greatest incidence of Sporozoan infections was in the following habitats: WithMattesia dispora: Kabashi 80% and Strellci 74%; withNosema heterosporum: Peja (Pe) 39% and Rugova 35 %; withAdelina mesnili: Kashica 28%, Strellci and Gjakova 21%.Further data from table 3 indicate that theE. kühniella larvae infected withBacillus thuringiensis were spread relatively widely and evenly throughout all the examined habitats in the area of Kosova. But onlyEphestia kühniella was infected at all of 22 localities.  相似文献   

13.
Due to the fact that the persistence ofBacillus thuringiensis (B.t.) is very short in the field as affected by exposure to ultraviolet radiation, some biochemical approaches have been adopted in an attempt to increase potentiation of the pathogen against the two lepidopterous corn borers,Chilo agamemnon andOstrinia nubilalis. These approaches were based on the incorporation of some selected non-toxic chemical compounds with different modes of action with the endotoxin ofB.t. fed to the larvae and thus resulting in its potentiation. Among the compounds tested, some representatives of inorganic salts, organic acids, protein and lipid solubilizing agents, amino acids and amides showed an obvious potentiation to the endotoxin activity against the target insects. Inorganic salts, such as, calcium oxide, calcium carbonate, zinc sulphate and potassium carbonate at 0.1% potentiated the activity of the product Dipel 2X (B.t. var.kurstaki) against the two tested species in varying degrees. With regard to protein solubilzing agents, urea, sodium thioglycollate and EDTA enhanced the potency ofB.t. againstO. nubilalis with a fold increase of 1.4–2.3. The lipid emulsifying agent Tween 80 (0.5%), caused 1.3 fold increase in the potency ofB.t. With respect toC. agamemnon, sodium thioglycollate and EDTA (0.1%) were effective in potentiating the activity ofB.t. with fold increase of 3.1 and 1.2, respectively, while urea caused a decrease in the potency ofB.t as compared with the control. The lipid emulsifying agent Tween 80 (0.5%) caused 1.3 fold increase in the potency ofB.t. The potentiating effect of aromatic compounds is not obvious with respect to the tested insect species. With amino acids and amides, it appears that some of the tested compounds enhanced the potency ofB.t. against the tested insect species but in varying degrees. The mode of action of the tested compounds has been discussed in the light of the results obtained.  相似文献   

14.
The relation between the pathogenBacillus thuringiensis and the predatorOrius albidepennis (Hem.: Anthocoridae) associated with the greasy cutwormAgrotis ypsilon (Lep.) has been investigated. The biology of the predator showed to be affected in terms of nymphal duration, rate of food consumption and egg production when the predator larvae were fed on treated eggs or neonate larvae of the host (A. ypsilon). The effect of B-exotoxin (thuringiensin) on the predator has been also demonstrated.  相似文献   

15.
Zusammenfassung Es konntenBacillus-Isolate gefunden werden, die sich in Keimungsversuchen an Samen als antagonistisch gegenüberPythium aphanidermatum undRhizoctonia solani erwiesen. Die Versuche wurden mit Bohnen- und Gurkensamen durchgeführt. Die wirksamsten Antagonisten konnten in infizierter Erde Auflaufraten bei Gurken von 40–60% erzielen.Die Wirksamkeit der Antagonisten an Bohnen war niedriger, hier lagen die Keimraten kaum höher als 30%. Offenbar hängt die Wirksamkeit derBacillus-Antagonisten von der Fähigkeit ab Antibiotika zu produzieren und in Konkurrenz zu anderen Mikroorganismen zu treten.
Antagonismin vivo ofBacillus spp. againstRhizoctonia solani andPythium spp.
In seed germination tests some isolates ofBacillus spp. showed antagonistic effects againstPythium aphanidermatum andRhizoctonia solani. In thoroughly infected soil, cucumber seeds reached a 40–60% rate of germination in the presence of the best antagonists. Protection to bean seeds was less effective; the germination rate was hardly better than 30%. The efficiency of antagonism reached by several isolates ofBacillus spp. appears to depend on their capacity to compete with other microorganisms or to produce antibiotic substances.

Mit 4 Abbildungen  相似文献   

16.
Summary Spraying Toxaphen against mice in forest cultures seems to be doubtful on the strength of side effects. The effectiveness of toxic baits for mice control should be increased by raising attractiveness as well as by reducing the size of baits. Experiments showed that Tetrachlorvinfos can be used forHylobius-control in place of DDT. Within young coniferous stands cleared by chemicals bark beetles can be controlled by felled stems sprayed with BHC. For avio chemic measures against larvae in the crowns of conifer the best results were obtained by using insecticides mixed with Diesel oil.   相似文献   

17.
On the hourly activity of certain Lepidopterous cotton pests as indicated by light-trap catches.The curves illustrating the hourly catches in an ultra violet trap of six species of cotton insect pests indicate the following:The cotton leaf-worm mothsSpodoptera littoralis are active all the night, with two distinct peaks, the first about 3 hours after sunset and the second about 3 hours before sunrise.The lesser cotton leaf worm mothsSp. exigua are mainly active during the second half of the night.The pink boll wormPectinophora gossypiella, the spiny boll worm.Earias insulana and the American boll wormHeliothis zea are, as a rule, more active during the first half of the night. Their activity diminishes gradually after midnight. Within the three species, the curve representingH. zea maintains an intermediate position between those ofP. gossypiella andE. insulana.The pattern of night activity of the cutworm,Agrotis ypsilon, resembles those of the three boll-worms.  相似文献   

18.
The molluscicidal activity of Thuricide used as bacterial insecticide,Bacillus thuringiensis, againstBiomphalaria alexandrina andBulunus truncatus was tested.The obtained results indicate that Thuricide possess a mollus-cicidal activity against both snails species.B. truncatus was more sensitive to the action of Thuricide. However the slope function of the LC50 forB. alexandrina was significantly higher than that forB. truncatus. The mortality rate of exposedB. alexandrina increased by increasing the exposure time.Exposure ofB. alexandrina to low concentration of Thuricide caused a significant decrease in both ovipository activity and size of egg masses and reduced the percentage of egg hatchability.
Zusammenfassung Es wurde die molluscizide Wirkung von Thuricide (Bac. thuringiensis) gegen die SchneckenBiomphalaris alexandrina undBulunus truncatus getestet. Die Ergebnisse zeigen, daß Thuricide für beide Schnecken molluscizid war.B. truncatus erwies sich als empfindlicher, doch war die Neigungs-Funktion des LC50-Wertes fürB. alexandrina signifikant höher als fürB. truncatus. Die Mortalitätsrate vonB. alexandrina erhöhte sich mit zunehmender Expositionszeit. Die Exposition vonB. alexandrina gegenüber geringen Konzentrationen von Thuricide verursachte eine signifikante Verringerung sowohl der Eiablage-Aktivität als auch der Größe der Eigelege sowie des Schlüpfprozents der Eier.

With 3 tables  相似文献   

19.
A laboratory study revealed that females of the phytoseiid mite, Amblyseius swirskii Athias-Henriot, fed on protonymphs of their own species or of other predatory mites i.e. Agistemus exsertus Gonzales and Euseius scutalis Athias-Henriot exhibited a marked decline in their fecundity and a shortening in their longevity. Moreover, the rate of predation was also reduced. When A. swirskii females were fed on nymphs of the two-spotted spider mite Tetranychus urticae Koch after having been fed previously on protonymphs of either A. swirskii or A. exsertus increases in the rates of oviposition and consumption were observed, although these rates were lower than those of conspecific females reared continuously on the two-spotted spider mite only.  相似文献   

20.
Zusammenfassung Durch den Einsatz eines Doppelrotors konnte die Durchsatzleistung beim Prallvorgang von Mehlen von 7 t/h auf 12 t/h bei gleichzeitiger vollständiger Abtötung der Eier vonEphestia kuehniella gesteigert werden.Bei der Prallung von Grießen in Prallmaschinen kann durch Verringerung der Umlaufgeschwindigkeiten der Prallbolzen eine unerwünschte Verfeinerung des Produktes vermieden werden. Eine Abtötung von Mehlmotteneiern ist bei Leistungen von mindestens 12 t/h weiterhin gewährleistet.
Use of impact machines to control the Mediterranean Flour MothEphestia kuehniella (Lepidoptera: Pyralidae) in flour and semolina
By using a double rotor system in impact machines for flour treatment the capacity can be increased from 7 t/h to 12 t/h and still showing 100% mortality of eggs from the Mediterranean Flour MothEphestia kuehniella.By semolina treatment in impact machines the velocity of the bolts can be reduced to insure that the granulation of the treated product is not influenced to an unacceptable degree. A 100% kill ofE. kuehniella eggs can be reached for a capacity of at least 12 t/h.

Mit 3 Tabellen  相似文献   

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