SUSCEPTIBILITY OF SOME FOREST INSECTS TO MIXTURES OF COMMERCIAL BACILLUS THURINGIENSIS AND CHEMICAL INSECTICIDES, AND SENSITIVITY OF THE PATHOGEN TO THE INSECTICIDES

1972 ◽  
Vol 104 (9) ◽  
pp. 1419-1425 ◽  
Author(s):  
Oswald N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Feeding Activity ◽  
Low Doses ◽  
Chemical Insecticide ◽  
Drastic Reduction ◽  
Hyphantria Cunea ◽  
Test Species ◽  
Relative Susceptibility ◽  
Forest Insects ◽  
Low Concentrations

AbstractExperiments were designed to determine the effects of low doses of some insecticides on the viability and physiological characteristics of commercial Bacillus thuringiensis (Berliner) as a prelude to studies on the susceptibility of lepidopterous forest defoliators to mixtures of bacteria and insecticides.The results show that the insecticides tested had no effect on viability or physiological integrity of the bacteria.Bacteria–insecticide combination effects varied from strongly antagonistic to strongly supplemental depending on insecticide or Thuricide® formulations and concentrations and on the relative susceptibility of the test species to either agent applied separately. Pyrethrum at 10−3 was highly potentiating to BT at 10−1 against third instar Halisidota argentata. Among Hyphantria cunea, a supplemental effect always resulted from combining Thuricide® at 10−2 with low concentrations of malathion, phosphamidon, or pyrethrum.There was generally a drastic reduction in feeding activity among BT-treated insects and a further reduction among BT-chemical-insecticide-treated ones compared with controls.

scholarly journals THE USE OF AGENTS BASED ON THE BACTERIUM BACILLUS THURINGIENSIS VAR. ISRAELENSIS FOR MOSQUITO CONTROL

2019 ◽  
Vol 98 (8) ◽  
pp. 893-896
Author(s):  
Svetlana A. Roslavtseva
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Synergistic Effect ◽  
Mosquito Control ◽  
Mosquito Species ◽  
Bacillus Sphaericus ◽  
Development Of Resistance ◽  
Blood Sucking ◽  
Low Concentrations ◽  
Bacterium Bacillus

Mosquito control is necessary to improve the epidemic and, consequently, the sanitary and hygienic situation in human settlements. At the same time, the safest and more environmentally friendly way of controlling is not the fight against adult mosquitoes, but the treatment of reservoirs with microbiological larvicides based on entomopathogenic, aerobic, spore-forming, saprophytic bacteria Bacillus thuringiensis (de Barjac) (Bti). A new serotype of the bacterium B. thuringiensis was found in Israel in the Negev desert. This serotype being more active against larvae of blood-sucking and non-blood-sucking mosquitoes and midges than previously known serotypes, was named israelensis. Bti endotoxin is a typical insecticide with intestinal type of action for different mosquito species. For example, Bti H14 is highly insecticidal to the larvae of Aedes aegypti and Ae. albopictus at very low concentrations. The parasporal body (endotoxin crystal), a crystalline protein consisted of four main polypeptides and two minor polypeptides, possesses of a larvicidal action. Larvicidal activity is associated with a synergistic effect in a combination of four polypeptides. The possibility of development of resistance to products based on Bti and Bacillus sphaericus in populations of mosquitoes (Culicidae) was investigated. The use of domestic microbiological formulations based on Bti («Baktitsid», «Larviol-pasta», and «Antinat») was shown an eradication the larvae of bloodsucking mosquitoes and midges to be possible and rational, since they are not generated resistant populations of mosquitoes. This is confirmed by more than 30 years of the use of such formulations.

scholarly journals Increased responsiveness in feeding behaviour of Caenorhabditis elegans after experimental coevolution with its microparasite Bacillus thuringiensis

2011 ◽  
Vol 8 (2) ◽  
pp. 234-236 ◽  
Author(s):  
Rebecca D. Schulte ◽  
Barbara Hasert ◽  
Carsten Makus ◽  
Nico K. Michiels ◽  
Hinrich Schulenburg
Keyword(s):  
Caenorhabditis Elegans ◽  
Bacillus Thuringiensis ◽  
Feeding Activity ◽  
Free Food ◽  
Immune System Activation ◽  
Evolution Experiment ◽  
Food Conditions ◽  
System Activation ◽  
Defence Strategy ◽  
Host Parasite

Immune responses, either constitutive or induced, are costly. An alternative defence strategy may be based on behavioural responses. For example, avoidance behaviour reduces contact with pathogens and thus the risk of infection as well as the requirement of immune system activation. Similarly, if pathogens are taken up orally, preferential feeding of pathogen-free food may be advantageous. Behavioural defences have been found in many animals, including the nematode Caenorhabditis elegans . We here tested nematodes from a laboratory based evolution experiment which had either coevolved with their microparasite Bacillus thuringiensis (BT) or evolved under control conditions. After 48 generations, coevolved populations were more sensitive to food conditions: in comparison with the controls, they reduced feeding activity in the presence of pathogenic BT strains while at the same time increasing it in the presence of non-pathogenic strains. We conclude that host–parasite coevolution can drive changes in the behavioural responsiveness to bacterial microbes, potentially leading to an increased defence against pathogens.

scholarly journals Sequential application of bio-pesticide, botanical and chemical insecticide to manage aphid and pod borer attacking yard long bean

2017 ◽  
Vol 42 (3) ◽  
pp. 531-538 ◽  
Author(s):  
MR Amin ◽  
AA Tarif ◽  
MM Rahman ◽  
MM Hossain ◽  
F Ge
Keyword(s):  
Bacillus Thuringiensis ◽  
Pest Management ◽  
Vigna Unguiculata ◽  
Untreated Control ◽  
Management Strategies ◽  
Aphid Population ◽  
Neem Oil ◽  
Chemical Insecticide ◽  
Pod Borer ◽  
Population Reduction

Present study evaluated the effect of sequential application of a bio-pesticide (Bacillus thuringiensis subsp. Kurstaki) (Bt), a botanical (neem oil) and a chemical insecticide (cypermethrin 25EC) as well as cypermethrin 25EC alone in the management of aphid (Aphis craccivora) and pod borer (Maruca vitrata) attacking yard long bean (Vigna unguiculata sesquipedalis) in the field. In each treatment Bt, neem oil and cypermethrin were applied in alternative sequence as well as cypermethrin alone at 07 days intervals. All the treatments reduced aphid population and flower infestation after 24, 48 and 72h of treatment compared to untreated control. Aphid population reduction by the treatments over control was ranged from 34.4 to 71.9%, and the treatment with cypermethrin alone had the lowest abundance of aphid and flower infestation. The Bt followed by neem oil and cypermethrin significantly reduced the pod infestation by pod borer and increased yield (38.9–41.4%) over control with BCR: 1.85-2.16. Use of cypermethrin alone was most effective and showed the lowest pod infestation and revealed the increased yield over control (47.7%) with BCR 4.70. Considering the hazardous affect of cypermethrin alone, its application followed by bio-pesticide and botanical sequentially would be promising components for integrated pest management strategies against aphid and pod borer attacking yard long bean.Bangladesh J. Agril. Res. 42(3): 531-538, September 2017

EFFICACY OF MIXTURES OF BACILLUS THURINGIENSIS, VIRUSES, AND CHLORDIMEFORM AGAINST INSECTS ON CABBAGE

1978 ◽  
Vol 110 (4) ◽  
pp. 443-448 ◽  
Author(s):  
R. P. Jaques ◽  
D. R. Laing
Keyword(s):  
Bacillus Thuringiensis ◽  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Autographa Californica ◽  
Granulosis Virus ◽  
Growing Seasons ◽  
Low Concentrations ◽  
Materials Used ◽  
Nuclear Polyhedrosis ◽  
Field Plots

AbstractThe efficacy of mixtures of chlordimeform with Bacillus thuringiensis and(or) Autographa californica nuclear polyhedrosis virus and Pieris rapae granulosis virus against Trichoplusia ni and Pieris rapae on the late cabbage was assessed in field plots over four growing seasons. Mixtures of 0.07 kg of chlordimeform/ha (1/8 of the recommended dosage) with low concentrations of the microbial insecticides were as effective or more effective than the materials used alone at full rates. The advantages of such mixtures in pest management are discussed.

Characterization ofBacillus thuringiensismutants and natural isolates by molecular methods

1997 ◽  
Vol 43 (5) ◽  
pp. 403-410 ◽  
Author(s):  
Yong Chul Jung ◽  
Sung Uk Kim ◽  
Song Hae Bok ◽  
Ho Yong Park ◽  
Jean-Charles Côté ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Bacillus Thuringiensis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Rice Grain ◽  
Chain Reaction ◽  
Hyphantria Cunea ◽  
Natural Isolates ◽  
Grain Dust ◽  
Polymerase Chain

Two Bacillus thuringiensis var. kurstaki HD-1 mutants, two Bacillus thuringiensis var. israelensis HD-500 mutants, and four rice grain dust isolates were characterized using microscopic examination and protein profiles of purified crystals on sodium dodecyl sulfate – polyacrylamide gel electrophoresis. Specific detection of cryI- and cryIV-type genes was performed in a polymerase chain reaction using cryI and cryIV-specific oligonucleotide primers. The cry-type genes under study consisted of cryIA(a), cryI(A)b, cryI(A)c, cryIB, and cryIV. Presence or absence of the cryI- and cryIV-type genes was further confirmed by Southern blotting followed by hybridization with specific cryI and cryIV gene fragments. A genetically modified strain of B. thuringiensis var. kurstaki HD-1, called OZK-13 and obtained following mutagenesis with ozone, was shown to contain cryIA(a), cryIA(b), and cryIA(c) genes. Another kurstaki HD-1 mutant, called NGK-13 and obtained following treatment with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), was shown to have lost the cryIA(b) gene while retaining the cryIA(a) and cryIA(c) genes. NGI-23-1, an oligosporogenous–multicrystalliferous mutant of B. thuringiensis var. israelensis (Bti) HD-500, obtained following treatment with MNNG contained cryIV-type genes. NGI-22, an oligosporogenous–acrystalliferous mutant of Bti HD-500, contained no cryI- nor cryIV-type genes. The rice grain dust isolate BT-285 contained the cryIA(a) and cryIA(c) genes. Isolate BT-14 contained only the cryIA(c) gene, whereas isolate BT-209 contained cryIA(a), cryIA(b), and cryIB genes. Isolate BT-205 contained no cryI- nor cryIV-type genes. Bacillus thuringiensis mutants and natural isolates shown to contain cryI-type genes were tested for their insecticidal activities in a series of bioassays against Hyphantria cunea Drury (Lepidoptera: Arctiidae). All cryI-carrying strains were toxic against the insect larvae. BT-205 was also tested and exhibited no toxicity against the insect larvae.Key words: Bacillus thuringiensis, δ-endotoxin crystal, cry-type genes, polymerase chain reaction.

scholarly journals Effects of gallic acid and Zn, Cu, and Ni on antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis

2021 ◽  
Author(s):  
Elif Fatma Topkara ◽  
Oğuzhan Yanar ◽  
Fatma Gönül Solmaz
Keyword(s):  
Bacillus Thuringiensis ◽  
Gallic Acid ◽  
Antioxidant Enzyme ◽  
Enzyme Activities ◽  
Antagonistic Effect ◽  
Metal Exposure ◽  
Antioxidant Enzyme Activities ◽  
Glutathione Peroxidase Activity ◽  
Hyphantria Cunea ◽  
Antagonistic Effects

Abstract The effects of copper, nickel, and zinc and the potent antioxidant gallic acid on the antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis subsp. kurstaki have been identified in this study. With metal exposure, all the enzyme activities have increased. Antagonistic effects were observed in the combination of gallic acid with all three metals on the activities of superoxide dismutase and catalase. In glutathione peroxidase activity, an antagonistic effect was observed in gallic acid plus nickel group, while there was a synergistic effect for gallic acid plus zinc and gallic acid plus copper. Activities of these enzymes in larvae exposed only to the metals increased in the infected groups; while exposure to gallic acid alone elicited a decrease. As a consequence, it was found that enzyme activities were affected by both metals and gallic acid and infection.

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