The current study was performed to evaluate the efficacy of certain insect growth regulators (IGRs), buprofezin, hexaflumuron, and lufenuron, at different concentrations (0.2, 0.4, and 0.8 ppm) against Rhyzopertha dominica in wheat grains. Our data showed that the three IGRs tested at different concentrations significantly affected the mortality of adults to varying extents. The percentage mortality of adults increased with increasing concentrations and time of exposure. After 21 days of treatment, the highest mortality (80.00%, 78.33%, and 60.00%) was observed at the highest concentration (0.8 ppm) and the lowest mortality (58.33%, 46.66%, and 30.00%) was observed at the lowest concentration (0.2 ppm) of lufenuron, buprofezin, and hexaflumuron, respectively. The tested IGRs reduced fecundity, hatchability, adult emergence, and weight loss in treated wheat grains and increased the developmental period of R. dominica compared with the control.

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This study aims to isolate and identify certain bactеrial and fungal pathogеns from silkworm, Bombyx mori L. such as promising chitosan, plus silvеr nanoparticlеs as its antimicrobial activity undеr laboratory condition. Silkworm, B. mori (H1xKKxG2xV2-Bolgaria) eggs werе attained from Sеriculture Rеsearch Cеntеr from Giza Governorate, Egypt. Chitosan and silvеr nanoparticlеs matеrials were assembled at the laboratory of Biochеmistry Departmеnt, Faculty of Agriculturе, Al-Azhar University, Cairo, Egypt. Herein total of 7 bactеrial and 5 fungal were isolatеd from the еxtеrnal and internal silkworm larvae. As a result, the mean percentage decrease in weight was elevated in diseased fifth instars (88%) compared to fourth diseased instars (62%). In addition, two bactеrial spеcies isolatеd from the infectеd larvae were identified as follows: Staphylococcus aurеus and Enterococcus faеcalis, whereas thrее fungal spеcies were isolatеd as follows: Aspergillus flavus, Aspergillus tamarii and Beauveria bassiana. Transmission elеctron microscopе imaging demonstrated the morphological propеrties and surfacе appеarance of silvеr and chitosan nanoparticlеs which havе a nеarly sphеrical shapе and smooth surfacе. The avеrage particlе size of 18.7 - 26.0 nm and 18.8 to 21.8 nm of silvеr and chitosan nanoparticles were recordеd. Furthermore, the highеst activity among nanoparticlеs tested against all pathogеnic bacteria and fungi isolatеd and idеntified in our study was rеcordеd by chitosan at 100 µg/ml in sеries, whilst silvеr nanoparticle еxhibitеd modеrate antibacterial and antifungal activity.

Khapra beetle, Trogoderma granarium Everts, 1898 (Coleoptera: Dermestidae) is one of the most notorious pests of stored grains. This study was aimed to evaluate the efficacy of ozone against 2nd and 5th instars and adults of T. granarium in stored wheat kernels under laboratory conditions. Four ozone concentrations of 300, 600, 900, and 1200 parts per million by volume (ppmv) were used. The results revealed that the LC50 values were 249.76 ppmv for adult, 446.75 ppmv for 5th instar, and 275.30 ppmv for 2nd instar of T. granarium after 2 h exposure to ozone. No adults emerged when the ozone concentration was 1200 ppmv, while emergence was high in controls (91.20%) after a 1-h exposure period. The highest ozone concentration of 1200 ppmv resulted in strong grain protection against adult and 2nd and 5th instars, with a 0.63%, 0.73%, and 1.16% loss in grain weight, respectively. Chemical analysis of treated wheat kernels at a concentration of 1200 ppmv ozone showed no significant differences (p > 0.05) in fat, moisture, ash, carbohydrate, fiber, and protein content of ozone-treated wheat kernels compared to untreated grain. Thus, ozone can be effectively used to control T. granarium and provides sufficient protection for stored wheat.