<abstract xmlns="http://www.w3.org/1999/xhtml">We estimated the usefulness of spore-crystals preparations of the two <italic>B. thuringiensis</italic> isolates, MPU B9 and MPU B54, for reducing the number of pests. The potential insecticidal toxicities of <italic>B. thuringiensis</italic> isolates were assessed by the analysis of the genes coding for crystalline proteins. The activities of spore-crystals preparations were determined against <italic>Dendrolimus pini</italic> L. (Lepidoptera: Lasiocampidae) and compared with the toxicity of spores and crystals of <italic>B. thuringiensis</italic> subsp. <italic>kurstaki</italic> HD-1 from commercial biopesticide Foray. Although the analysis of crystalline toxin gene profiles indicated potentially higher activities of MPU B9 and MPU B54 crystals against the pests than that of HD-1, the toxicities of isolate and HD-1 preparations against <italic>D. pini</italic> caterpillars were similar. The LC50 amounted to 3.42×104 spores and crystals for HD-1, 3.36×104 for MPU B9 and 3.5×104 for MPU B54. Additionally, the toxicity of the MPU B54 preparation was evaluated against <italic>Spodoptera exigua</italic> (Hubner) (Lepidoptera: Noctuidae). The LC50 was 4.5×105 spores and crystals of MPU B54, and 2.69×106 spores and crystals of HD-1. The LC50 of the MPU B54 preparation against <italic>S. exigua</italic> was approximately six-fold higher than that of HD-1. However, due to the very wide fiducidal limits for LC50 values, which for both preparations overlap to a large extent, the toxicity of the preparations should be considered the same. The varied profiles of crystalline toxin genes and important toxicity of spore-crystal mixtures of isolates against <italic>S. exigua</italic> and <italic>D. pini</italic> indicate the effectiveness of the mixtures against pests and make the strains an alternative for HD-1 for reducing the number of insects.</abstract>

We estimated the usefulness of spore-crystals preparations of the two B. thuringiensis isolates, MPU B9 and MPU B54, for reducing the number of pests. The potential insecticidal toxicities of B. thuringiensis isolates were assessed by the analysis of the genes coding for crystalline proteins. The activities of spore-crystals preparations were determined against Dendrolimus pini L. (Lepidoptera: Lasiocampidae) and compared with the toxicity of spores and crystals of B. thuringiensis subsp. kurstaki HD-1 from commercial biopesticide Foray. Although the analysis of crystalline toxin gene profiles indicated potentially higher activities of MPU B9 and MPU B54 crystals against the pests than that of HD-1, the toxicities of isolate and HD-1 preparations against D. pini caterpillars were similar. The LC50 amounted to 3.42×104 spores and crystals for HD-1, 3.36×104 for MPU B9 and 3.5×104 for MPU B54. Additionally, the toxicity of the MPU B54 preparation was evaluated against Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae). The LC50 was 4.5×105 spores and crystals of MPU B54, and 2.69×106 spores and crystals of HD-1. The LC50 of the MPU B54 preparation against S. exigua was approximately six-fold higher than that of HD-1. However, due to the very wide fiducidal limits for LC50 values, which for both preparations overlap to a large extent, the toxicity of the preparations should be considered the same. The varied profiles of crystalline toxin genes and important toxicity of spore-crystal mixtures of isolates against S. exigua and D. pini indicate the effectiveness of the mixtures against pests and make the strains an alternative for HD-1 for reducing the number of insects.

Activity of spore-crystal mixtures of new <italic>Bacillus thuringiensis</italic> strains against <italic>Dendrolimus pini</italic> (Lepidoptera: Lasiocampidae) and <italic>Spodoptera exigua</italic> (Lepidoptera: Noctuidae)

Faculty of Biology, Department of Microbiology

General Directorate of State Forest, Forest Protecting Unit Łopuchówko

Folia Forestalia Polonica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Activity of spore-crystal mixtures of new  strains against  (Lepidoptera: Lasiocampidae) and  (Lepidoptera: Noctuidae)

We estimated the usefulness of spore-crystals preparations of the two B. thuringiensis isolates, MPU B9 and MPU B54, for reducing the number of pests. The...

Activity of spore-crystal mixtures of new Bacillus thuringiensis strains against Dendrolimus pini (Lepidoptera: Lasiocampidae) and Spodoptera exigua (Lepidoptera: Noctuidae)

Published Online: Jul 20, 2018

Page range: 91 - 98

Received: Aug 17, 2017

Accepted: May 07, 2018

DOI: https://doi.org/10.2478/ffp-2018-0009

Keywords
bacterial toxins, insecticidal toxicity, Lepidoptera, plant protection

© 2018 Edyta Konecka et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Activity of spore-crystal mixtures of new Bacillus thuringiensis strains against Dendrolimus pini (Lepidoptera: Lasiocampidae) and Spodoptera exigua (Lepidoptera: Noctuidae)

Published Online: Jul 20, 2018

Page range: 91 - 98

Received: Aug 17, 2017

Accepted: May 07, 2018

DOI: https://doi.org/10.2478/ffp-2018-0009

Keywordsbacterial toxins, insecticidal toxicity, Lepidoptera, plant protection

© 2018 Edyta Konecka et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
bacterial toxins, insecticidal toxicity, Lepidoptera, plant protection