Isolation, morphological and molecular characterization of Bacillus thuringiensis strains against Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae)

Zorzetti, Janaina; Ricietto, Ana Paula Scaramal; Fazion, Fernanda Aparecida Pires; Meneghin, Ana Maria; Neves, Pedro Manuel Oliveira Janeiro; Vilas-Bôas, Laurival A.; Vilas-Bôas, Gislayne Trindade

doi:10.1016/j.rbe.2018.07.002

Cited by 7 publications

(7 citation statements)

References 37 publications

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“…34 Moreover, similar bioassays have resulted in 80-100% mortality of Coffee berry borer firstto fifth-instar larvae (Hypothenemus hampei, Coleoptera: Curculionidae). 17,35 In our study, Bt israelensis caused 65-82% greater mortality and a 70-82% feeding reduction relative to the control group, in adult weevils, thus suggesting that this strain has the potential to be used for management of the forest pest H. abietis. Also, ours and previous results suggest that Coleopteran larvae and adults may be more susceptible to Bt israelensis toxins than expected, and its Diptera-specificity may need reconsideration.…”

Section: Toxicity Of Individual Bt Strainsmentioning

confidence: 57%

“…For instance, the Lepidopteran‐specific strain Bt kurstaki (Raven® formulation; Cry1Ac toxin) has been shown to yield higher mortality of a leaf beetle than the Coleopteran‐specific Bt tenebrionis ( Cry3Aa toxin) 22 . However, these same Cry1 and Cry3 toxins have little toxic effects on the Coffee berry borer 35 . Hence, results from our study are a valuable addition to our knowledge on the nonspecificity of Bt strains, which certainly deserves further consideration.…”

Section: Discussionmentioning

confidence: 72%

“…22 However, these same Cry1 and Cry3 toxins have little toxic effects on the Coffee berry borer. 35 Hence, results from our study are a valuable addition to our knowledge on the nonspecificity of Bt strains, which certainly deserves further consideration.…”

Section: Toxicity Of Individual Bt Strainsmentioning

confidence: 78%

“…For example, bioassays with spore suspensions from Bt israelensis in an artificial diet yielded up to 100% mortality of Cotton ball weevil third‐instar larvae ( Anthonomus grandis , Coleoptera: Curculionidae) 34 . Moreover, similar bioassays have resulted in 80–100% mortality of Coffee berry borer first‐ to fifth‐instar larvae ( Hypothenemus hampei , Coleoptera: Curculionidae) 17,35 . In our study, Bt israelensis caused 65–82% greater mortality and a 70–82% feeding reduction relative to the control group, in adult weevils, thus suggesting that this strain has the potential to be used for management of the forest pest H. abietis .…”

Section: Discussionmentioning

confidence: 99%

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A major forest insect pest, the pine weevil Hylobius abietis, is more susceptible to Diptera‐ than Coleoptera‐targeted Bacillus thuringiensis strains

Tudoran

Nordlander

Karlberg

et al. 2020

Pest Management Science

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BACKGROUND The pine weevil (Hylobius abietis) is a major forest regeneration pest causing high levels of seedling mortality and economic losses. Current management relies on silviculture, stem coatings and insecticides. Here we evaluated for the first time the effects of Bacillus thuringiensis (Bt) strains on H. abietis adults: two producing the Coleoptera‐targeted toxins Cry3Aa (Bt tenebrionis NB‐176) and Cry8Da (Bt galleriae SDS‐502), and one producing the Diptera‐targeted Cry10A (Bt israelensis AM65‐52). Choice and nonchoice assays using individual and mixtures of Bt formulations, containing these strains respectively, were conducted. RESULTS We found that Bt had toxic and lethal effects on H. abietis, but effects varied with strain and formulation concentration. The Diptera‐targeted Bt israelensis had the most negative effects on weevil weight, feeding and mortality (70–82% feeding reduction, 65–82% greater mortality than control), whereas the effect was lower for the Coleoptera‐specific Bt tenebrionis (38–42%; 37–42%) and Bt galleriae (11–30%; 15–32%). Reduced weevil feeding was observed after 3 days, and the highest mortality occurred 7–14 days following Bt exposure. However, we found no synergistic toxic effects, and no formulation combination was better than Bt israelensis alone at reducing consumption and survival. Also, pine weevils were not deterred by Bt, feeding equally on Bt‐treated and non‐Bt treated food. CONCLUSION There is potential to develop forest pest management measures against H. abietis that include Bt, but only the Diptera‐targeted Bt israelensis would provide effective seedling protection. Its Diptera‐specificity may need reconsideration, and evaluation of other Bt strains/toxins against H. abietis would be of interest. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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Section: Toxicity Of Individual Bt Strainsmentioning

confidence: 57%

Section: Discussionmentioning

confidence: 72%

Section: Toxicity Of Individual Bt Strainsmentioning

confidence: 78%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

A major forest insect pest, the pine weevil Hylobius abietis, is more susceptible to Diptera‐ than Coleoptera‐targeted Bacillus thuringiensis strains

Tudoran

Nordlander

Karlberg

et al. 2020

Pest Management Science

View full text Add to dashboard Cite

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“…Similarly, the LC 50 recorded in this research was about six orders of magnitude higher than the values obtained in a prior study, testing fourth-instar Aedes aegyptii larvae (2.061×10 -6 µg µl -1 ) (Hernández-Soto et al, 2009), probably because dipterans are more susceptible than coleopterans to Bti Cry proteins. Furthermore, previous research has focused on testing only Bt-sc against CBB larval stages (De-la-Rosa et al, 2005;López-Pazos et al, 2009;Zorzetti et al, 2018). Thus, this is the first evaluation of the susceptibility of H. hampei adults to Bt-sc from B. thuringiensis, either alone or mixed with a partially purified plant extract enriched in PI.…”

Section: Discussionmentioning

confidence: 99%

Soybean protease inhibitors increase Bacillus thuringiensis subs. israelensis toxicity against Hypothenemus hampei

et al. 2020

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Introduction. The coffee berry borer (Hypothenemus hampei Ferrari, CBB) is one of the most devastating pests on coffee plantations around the world. Although CBB is susceptible to the effect of δ–endotoxins of Bacillus thuringiensis subs. israelensis (Bti) at laboratory level, the efficacy of this control method is poor in the field, presumably due to the inactivation by digestive proteases different to those required for protoxin activation. Objective. To study whether the addition of a soybean flour extract enriched with protease inhibitors (PI), mixed with Bti crystals and spores (Bti-sc) in an artificial diet, could improve the toxicity of Bti against CBB. Materials and methods. This study was performed in San José, Costa Rica, between 2012 and 2013. A set of adult female CBB insects was exposed to a mixture containing different concentrations of a partially purified soybean meal extract with active PI and lyophilized Bti-sc, and were tested through a bioassay in artificial diet to estimate the sub-lethal concentration (LC50). The mortality results were validated by observing the dissected midgut, whose ultrastructure was analyzed by transmission electron microscopy. Results. The soybean extracts partially degraded the Bti-sc complex, it reduced its LC50 by almost four times (from 1.135 to 0.315 µg µl-1) and enhanced CBB mortality in a concentration-dependent manner. Histological analyses of the midgut confirmed this synergistic effect, since severe epithelial damage to the intestinal epithelium of CBB exposed to Bti-sc + PI was visualized compared to Bti-sc alone. Conclusions. The combination of a soybean extract enriched in PI and Bti-sc enhanced the mortality effect over CBB, which was confirmed by the midgut collapse. Soybean flour is a cost-effective supplement that could increase Bti effectiveness against CBB and delay the appearance of biological resistance.

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Entomopathogenic Microbes for Sustainable Crop Protection: Future Perspectives

Soumia

Krishna

Jaiswal

et al. 2020

Environmental and Microbial Biotechnology

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Isolation, morphological and molecular characterization of Bacillus thuringiensis strains against Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae)

Cited by 7 publications

References 37 publications

A major forest insect pest, the pine weevil Hylobius abietis, is more susceptible to Diptera‐ than Coleoptera‐targeted Bacillus thuringiensis strains

A major forest insect pest, the pine weevil Hylobius abietis, is more susceptible to Diptera‐ than Coleoptera‐targeted Bacillus thuringiensis strains

Soybean protease inhibitors increase Bacillus thuringiensis subs. israelensis toxicity against Hypothenemus hampei

Entomopathogenic Microbes for Sustainable Crop Protection: Future Perspectives

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