LC and LD50 values of bacillus thuringiensis serovar japonensis strain buibui toxin to oriental beetle and northern masked chafer larvae (coleoptera: Scarabaeidae)

Bacillus thuringiensis serovar japonensis strain Buibui has the potential to be an important control agent for pest scarabs. Bioassays were designed to test B. t. japonensis against two of the major turf and ornamental scarab pests infesting turfgrasses and ornamentals and to serve as a basis for further tests against other scarab pests. LC and LD50 values of B. t. serovar japonensis strain Buibui toxin and spores were determined by four different bioassays for the oriental beetle, Anomala orientalis (Waterhouse), and northern masked chafer, Cyclocephala borealis Arrow. Oriental beetle larvae were bioassayed in autoclaved and nonautoclaved soil from where they were collected (Kingston, RI [native]), in nonautoclaved soil from where the northern masked chafer larvae were collected (Groton, CT [foreign]), and per os. Northern masked chafer larvae were bioassayed in autoclaved and nonautoclaved soil from where they were collected (Groton, CT [native]), in nonautoclaved soil from where the oriental beetle larvae were collected (Kingston, RI [foreign]) and per os. LC50 values of 3.93 μg toxin/g autoclaved native soil, 1.80 μg toxin/g nonautoclaved native soil, and μ0.42 g toxin/g nonautoclaved foreign soil and an LD50 value of 0.41 μg per os were determined at 14 d for A. orientalis. LC50 values of 588.28 μg toxin/g autoclaved native soil, 155.10 μg toxin/g nonautoclaved native soil, 265.32 μg toxin/g nonautoclaved foreign soil, and LD50 of 5.21 μg per os were determined at 14 d (soils) and 10 d (per os) for C. borealis. There were significant differences in LC50 values for oriental beetles in autoclaved, nonautoclaved native soil and nonautoclaved foreign soil. There were significant differences in LC50 values for northern masked chafers in autoclaved and nonautoclaved native soil. B. t. japonensis can be applied now for control of oriental beetles at rates that are economically competitive with synthetic chemicals. If we can determine the component of nonautoclaved soil that enhances the activity of toxin, it may be possible to lower the rates of toxin needed for control to more economical levels for more difficult to control species such as the northern masked chafer. © 2009 Entomological Society of America

The Potential of a Novel Concept of an Integrated Bio and Chemical Formulate Based on an Entomopathogenic Bacteria, <i>Bacillus thuringiensis</i>, and a Chemical Insecticide to Control Tomato Leafminer, <i>Tuta absoluta</i> ‘(Meyrick)’ (Lepidoptera: Gelechiidae)

Tomato leafminer, Tuta absoluta (Meyrick), (Lepidoptera: Gelechiidae), poses severe threats to sustainable tomato production globally with a high capacity to develop resistance to pesticides. Recently, the management programs for this cosmopolitan pest have relied on combinations of chemical insecticides which exacerbate the problems of cross-resistance and adverse environmental effects. A novel concept of integrated formulates through combining a chemical insecticide model of lambda-cyhalothrin with Bacillus thuringiensis (Bt) products as the formulation core was explored and evaluated. The susceptibility of the second instar larvae of tomato leafminer to the original formulation of lambda-cyhalothrin, Dipel, XenTari, and Agree products was assessed and compared to the combined formulations. The positive and negative impacts of lambda-cyhalothrin on the viability and pathogenicity of Bt strains were tracked and documented. The physicochemical properties of the combined formulates were examined and compared to the international standards of pesticide formulations. The proposed integrated combined formulates of Dipel, XenTari, and Agree biopesticides with lambda-cyhalothrin showed an enhancing effect and had a higher potential than the originally manufactured formulations alone for about a 3.67–10.08-fold impact on larval mortality. Lambda-cyhalothrin had no significant adverse effect on either the viability of Bt strains or the physicochemical properties of combined co-formulates. Therefore, such integrated combined formulates would have the potential to be involved as an alternative or a complementary approach in pest management and pest resistance management tools for sustainable pest management

Enhanced toxicity of Bacillus thuringiensis subspecies kurstaki and aizawai to black cutworm larvae (Lepidoptera: Noctuidae) with Bacillus sp. NFD2 and Pseudomonas sp. FNFD1

Bacillus thuringiensis subspecies kurstaki and aizawai are important control agents for lepidopteran pests. Bioassays were designed to test B. t. kurstaki and aizawai against second- and-fourth instar black cutworm larvae with and without Bacillus sp. NFD2 and Pseudomonas sp. FNFD1 bacteria. B. thuringiensis subsp. aizawai (XenTari) was more toxic to both second- and fourth-instar black cutworm, Agrolis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), larvae than B. t. kurstaki (DiPel) at 7 d after treatment (DAT). When DiPel was combined with NFD2 or FNFD1 versus second instars, the LC 50s were 5.0X and 4.7X lower, respectively, than with DiPel alone. DiPel combined with both NFD2 and FNFD1 versus second instars resulted in an LC50 value 7.7X lower than with DiPel alone. When XenTari was combined with NFD2 or FNFD1 versus second instars, the LC50s were 5.2X and 3.8X lower, respectively, than with XenTari alone. XenTari combined with both NFD2 and FNFD1 versus second instars resulted in an LC50 9.7X lower than with XenTari alone. When DiPel was combined with NFD2 or FNFD1 versus fourth instars, the LC50s were 4.4X and 3.4X lower, respectively, than with DiPel alone. DiPel combined with both NFD2 and FNFD1 versus fourth instars resulted in an LC50 5.0X lower than with DiPel alone. When XenTari was combined with NFD2 or FNFD1 versus fourth instars, the LC50s were 5.7X and 3.3X lower, respectively, than with XenTari alone. XenTari combined with both NFD2 and FNFD1 versus fourth instars resulted in an LC50 6.7X lower than with XenTari alone. © 2011 Entomological Society of America

Enhanced toxicity of Bacillus thuringiensis japonensis strain Buibui toxin to oriental beetle and northern masked chafer (Coleoptera: Scarabaeidae) larvae with Bacillus sp. NFD2

Bacillus thuringiensis japonensis strain Buibui (Btj) has the potential to be an important control agent for pest scarabs. Bioassays using autoclaved and nonautoclaved soil showed there were always lower LC50 values associated with nonautoclaved soil. We identified five other bacteria found in the hemolymph of insects killed by Btj and used them in bioassays to see whether we could enhance the control achieved with Btj alone. One bacterium, designated NFD2 and later identified as a Bacillus sp., showed the greatest enhancement of Btj in preliminary experiments and was used in bioassays with Btj versus oriental beetle, Anomala orientalis (Waterhouse), and northern masked chafer, Cyclocephala borealis Arrow (Coleoptera: Scarabaeidae), larvae. This bacterium alone was nontoxic to grubs in bioassays. A combination of this bacterium with Btj in nonautoclaved soil resulted in a significantly lower LC50 value (0.23 g toxin per g soil) from all other treatments for A. orientalis with one exception; the LC50 where NFD2 was added back into autoclaved soil (0.29 g toxin per g soil). A combination of this bacterium with Btj in nonautoclaved soil resulted in a significantly lower LC50 value (48.29 g toxin per g soil) from all other treatments for C. borealis with the exception of the treatment where Bacillus sp. NFD2 was added back to autoclaved soil (96.87 g toxin per g soil) with Btj. This research shows that other soil bacteria can be used to enhance the toxicity of Btj and possibly other Bts. © 2010 Entomological Society of America

Influence of Non-Thermal Plasma on the Quality and Nutritional Content of Palm Dates

In this work, the surface dielectric barrier discharge (SDBD) plasma treatment was used to sterilize the palm date fruits. N2SPS, N2FNS, and hydroxyl radical have emerged in the emission spectrum of the plasma from SDBD. The effects of SDBD plasma on A. niger that was extracted from palm date varieties were investigated. After 15 days of incubation, the reduction of A. niger at a 3 min exposure time was 4 log. The total phenolic content of the Ajwa variety after SDBD plasma treatment has been documented as the highest value among the other varieties; it was 1.65-fold of the untreated one. The treated Ajwa variety using SDBD plasma has recorded the highest increase in antioxidant activity; it was increased to 67.69% compared to the control one. After SDBD plasma treatment, the HMF was not detected in the Maghol variety. According to the PCA model, the first two PCs demonstrated strong positive correlations with most of the examined variables and demonstrated a strong positive correlation between these variables when assessed in both untreated and treated with SDBD plasma of palm date types in this stud

Influence of Non-Thermal Plasma on the Quality and Nutritional Content of Palm Dates

In this work, the surface dielectric barrier discharge (SDBD) plasma treatment was used to sterilize the palm date fruits. N2SPS, N2FNS, and hydroxyl radical have emerged in the emission spectrum of the plasma from SDBD. The effects of SDBD plasma on A. niger that was extracted from palm date varieties were investigated. After 15 days of incubation, the reduction of A. niger at a 3 min exposure time was 4 log. The total phenolic content of the Ajwa variety after SDBD plasma treatment has been documented as the highest value among the other varieties; it was 1.65-fold of the untreated one. The treated Ajwa variety using SDBD plasma has recorded the highest increase in antioxidant activity; it was increased to 67.69% compared to the control one. After SDBD plasma treatment, the HMF was not detected in the Maghol variety. According to the PCA model, the first two PCs demonstrated strong positive correlations with most of the examined variables and demonstrated a strong positive correlation between these variables when assessed in both untreated and treated with SDBD plasma of palm date types in this stud