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. serovarjaponensis 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 microg toxin/g autoclaved native soil, 1.80 microg toxin/g nonautoclaved native soil, and 0.42 microg toxin/g nonautoclaved foreign soil and an LD50 value of 0.41 microg per os were determined at 14 d forA. orientalis. LC50 values of 588.28 microg toxin/g autoclaved native soil, 155.10 microg toxin/g nonautoclaved native soil, 265.32 microg toxin/g nonautoclaved foreign soil, and LD50 of 5.21 microg 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 LCo 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.
Bacillus thuringiensisjaponensis 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 LC, 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 microg 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 microg toxin per g soil). A combination of this bacterium with Btj in nonautoclaved soil resulted in a significantly lower LC50 value (48.29 microg 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 microg 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.
Thirty bacterial strains were successfully isolated from dead/diseased nymphs of the desert locust Schistocerca gregaria Forskal (Orthoptera: Acrididae) occurred in rearing cages at Egypt. Among them, two isolates, DL3 and DL4, showed a high biocidal activity against locust at preliminary bracketing bioassay. Molecular identification of the two bacterial isolates was carried out by sequencing the 16S rRNA gene and nucleotide blast of international GenBank, and the results showed that DL3 isolate was Bacillus cereus (KY630646) and DL4 isolate was Bacillus cereus (KY630647) with a 100% similarity with Bacillus cereus strain SZAN-2 (GU222440) and Bacillus cereus strain KPRR3 (KY556439), respectively. The insecticidal activity of both isolates against locust nymphs using leaf dipping and per os techniques proved that DL4 isolate was more efficient than DL3 and both of them have the potential to be successful biocidal agents to control desert locust.
The present study was carried out from November (2015) -October (2017 to determine the toxicological effects of pesticides exposure on agricultural application workers. Blood samples of the investigated workers were collected from Giza, Qalyubiyah and El-Buhayrah Governorates, Egypt. Thirty male individuals represented pesticide application workers were involved from the three governorates. Also, 25 male individuals (aged 18-55 years) were selected randomly from Cairo Governorate to represent the unexposed (control) group. Ten ml of blood sample per individual was collected and serological analysis for hematological (RBCs, TLC, Hb, PCV, MCV, MCH, MCHC), biochemical (ALT, AST, total protein, urea, creatinine and uric acid) and oxidative stress (GSH.R, MDA and AChE) parameters were carried out. About 53% of workers involved was with an average level of education, between 18 and 35 years of age (57%), working in their field for 6 to 10 years (40%), about eight hours a day for six days a week on average (67%). Hb, MCH, MCHC, ALT, AST, AlP, TP, urea, creatinine and MDA were increased significantly by 5. 58, 9.23, 3.75, 55.49, 42.44, 30.07, 6.83, 49.33, 25.48, and 133.02% respectively. While the levels of Alb, GSH.R and AChE activity were significantly decreased by 14.51, 8.33 and 21.04% respectively. a significant positive correlation between exposure duration and ALT, AST, creatinine, urea and MDA. While, there were significant negative correlations between exposure duration and total protein, alkaline phosphatase, AChE Activity, GSH.R, RBCs, Hb, PCV, MCV and MCH. Increasing of pesticide application workers vital parameters gives an indication of the occur-rence of various health consequences due to chronic exposure to pesticides. These results can be explained by the fact that the negligence of workers in following occupational safety and health measures from wearing protective tasks, not eating, drinking and smoking during the application of pesticides, resulting from the low awareness of workers about the risks of the materials dealt with and the decrease in their educational and cultural level increases the chances of exposure to the pesticide on the health of the worker.
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