Utilization of Several Biopolymers for Granular Formulations of Bacillus thuringiensis

Ramos, Lilia Hortencia Morales; McGuire, Morgan; Wong, Luis Jesús Galán

doi:10.1093/jee/91.5.1109

Cited by 16 publications

(8 citation statements)

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“…The use of feeding stimulants to increase the insect feeding response for insecticidal formulations has been widely studied, and a great variety of natural ingredients related to the insect consuming habits have been incorporated to such formulations. It is well known that cornstarch is one of the more successful polymers used for these kind of formulations (Dunkle and Shasha 1988;Bartelt et al 1990;McGuire et al , 1996Shasha 1990, 1992;Gillespie et al 1994;Tamez-Guerra et al 1996); however, by using it alone, lepidopteran larvae usually Þnd it unpalatable (Morales-Ramos et al 1998, Rosas-Garcṍa et al 2004. In this study, it is interesting to observe that feeding stimulants affected positively insect feeding response and prompted the larvae to ingest the formulations.…”

Section: Discussionmentioning

confidence: 99%

Design of a Bacillus thuringiensis-Based Formulation That Increases Feeding Preference on Spodoptera exigua (Lepidoptera: Noctuidae) Larvae

Rosas-García

Villegas-Mendoza²,

Torres-Ortega

2009

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A Bacillus thuringiensis (Bt)-based formulation intended to increase feeding response in Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) was developed. Eight matrices were prepared from natural ingredients and confronted with fresh maize leaves to select one highly palatable to larvae. The selected matrix was combined with Bt HD-125 strain at three different concentrations (30, 70, and 100 g/kg) of the spore-crystal complex to elaborate three insecticidal formulations. Effects caused by the matrix, including palatability, any adverse effect, and reduction in toxic activity of the strain, were tested on the formulations. Results indicated that the blend of modified cornstarch, porcine gelatin, and dried corncob was the most preferred by larvae. Formulations obtained were evaluated in mortality bioassays with neonate larvae in laboratory, using artificial diet, and in the greenhouse, with maize, Zea mays L., plants to compare their effectiveness when applied to natural food. In laboratory tests, all formulations, including a commercial formulation, were ingested by larvae causing high mortality in neonate larvae; in the greenhouse tests, formulations were also ingested causing mortality in larvae, overcoming commercial formulation effectiveness. Results suggest that the selected matrix combined with Bt 70 g/kg is the most suitable formulation to achieve effective control because this concentration acts faster than the lower concentration and is equal than the higher concentration. This formulation, designed specifically against a particular pest, is highly effective and offers a high potential for effective pest control.

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Section: Discussionmentioning

confidence: 99%

Design of a Bacillus thuringiensis-Based Formulation That Increases Feeding Preference on Spodoptera exigua (Lepidoptera: Noctuidae) Larvae

Rosas-García

Villegas-Mendoza²,

Torres-Ortega

2009

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“…Based on these characteristics, Capsul ™ was very useful in encapsulating the spore–crystal complex as an insoluble solid providing a free‐flowing powder that was very easy to disperse in water. The porcine gelatin was chosen because of its good adherent properties,22 which are very useful for field applications; moreover, this product has low cost and is readily available. Powdered sugarcane was included in the formulation owing to its feeding stimulant activity for larvae,29 and is required in very small amounts.…”

Section: Discussionmentioning

confidence: 99%

“…Spray‐dried formulations were prepared as follows: an aqueous suspension (2 L) was made with Capsul ™ , gelatin, powdered sugarcane and spore–crystal complex at room temperature, according to Table 1. The formulations were prepared at the recommended Bt concentration (70 g kg −1 ) for laboratory tests,22 but lower and upper concentrations were prepared to evaluate the toxic potential of the strain. The suspension was passed through a spray drier (Apex, Type SEE68 from Apex Construction Ltd, using a Watson‐Marlow 502 S pump) under the following conditions: inlet temperature 130–145 °C, outlet temperature 70–90 °C, pressure 2500–3250 mmHg, resistance level 4–6 and flow 7–12 mL min −1 .…”

Section: Experimental Methodsmentioning

confidence: 99%

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Laboratory and field tests of spray‐dried and granular formulations of a Bacillus thuringiensis strain with insecticidal activity against the sugarcane borer

Rosas-García¹

2006

Pest Management Science

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Formulations of Bacillus thuringiensis Berliner (Bt) with insecticidal activity against the sugarcane borer, Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae), were developed and tested under laboratory and field conditions. The formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a Bt var. kurstaki GM-34 strain from a non-sugarcane region as the active ingredient. The spore-crystal complex of this strain was mixed at three different concentrations (30, 70 and 100 g kg(-1)) with the other ingredients. The blends were prepared as spray-dried and granular formulations, and then submitted to laboratory tests with two day old larvae of D. saccharalis and field tests in sugarcane crops with natural sugarcane borer infestation. Spray-dried formulations in laboratory bioassays caused mortality near 100% with all three concentrations, and granular formulations caused mortality around 84%. The field tests showed that spray-dried formulations at 70 and 100 g kg(-1) concentrations were as effective as a commercial bioinsectide (Lepinox), while granular formulations were ineffective.

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“…starch-based granular formulations (Dunkle and Shasha, 1988;Gillespie et al, 1994;McGuire et al, 1990) has been the subject of recent interest for the delivery of B. thuringiensis and nucleopolyhedroviruses to noctuid pests (Morales-Ramos et al, 1998;Tamez-Guerra et al, 1998, 2000a, 2000b. One drawback of phagostimulant formulations is that they are invariably more expensive than simpler water-based sprays.…”

Section: Discussionmentioning

confidence: 99%

Granular phagostimulant nucleopolyhedrovirus formulations for control of Spodoptera frugiperda in maize

et al. 2002

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The efficacy of bioinsecticides that act by ingestion can be improved by the use of phagostimulant formulations that increase the consumption of the pathogen. A granule recipe comprising of pregelatinized flour, starch, ground maize cob, maize oil, and water was identified that was highly palatable to Spodoptera frugiperda larvae. To compare the performance of a multiple nucleopolyhedrovirus (SfMNPV) in aqueous spray and phagostimulant granules, multiple linear regression procedures were employed to analyze the results of seven independent field trials involving spray applications and eight independent field trials involving application of phagostimulant granules for control of S. frugiperda in maize. Prevalence of infection was positively correlated with the quantity of inoculum applied but negatively correlated with the interval between application and sampling of larvae for both granular and spray formulations. Virus-induced mortality was greater when inoculum was applied in granular than in spray formulation. A field experiment involving the application of 1:5 Â 10 12 occlusion bodies (OBs)/ha in quantities of 6, 18, and 32 kg granules/ha indicated that the quantity of granules applied did not significantly affect viral mortality at any timepoint. Persistence of activity of viral inoculum applied in spray or granular formulations was significantly greater when applied in the granular formulation, with approximately 23% of the original activity remaining at 8 days postapplication compared to <1% in the spray-treated plants. We conclude that the efficacy of SfMNPV was improved by formulation; the granular formulation caused a higher prevalence of infection in S. frugiperda larvae and persisted longer on crop foliage compared to an aqueous spray application. The cost of the formulation ingredients alone was approximately US$0.50/kg. When combined with the virus, the cost of the basic bioinsecticide components would be about US$17/ha, although this estimate does not include additional costs involved in the commercialization of a potential bioinsecticide product. Ó

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Utilization of Several Biopolymers for Granular Formulations of Bacillus thuringiensis

Cited by 16 publications

References 0 publications

Design of a <I>Bacillus thuringiensis</I>-Based Formulation That Increases Feeding Preference on <I>Spodoptera exigua</I> (Lepidoptera: Noctuidae) Larvae

Design of a <I>Bacillus thuringiensis</I>-Based Formulation That Increases Feeding Preference on <I>Spodoptera exigua</I> (Lepidoptera: Noctuidae) Larvae

Laboratory and field tests of spray‐dried and granular formulations of a Bacillus thuringiensis strain with insecticidal activity against the sugarcane borer

Granular phagostimulant nucleopolyhedrovirus formulations for control of Spodoptera frugiperda in maize

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