Termiticidal Effects and Morpho-Histological Alterations in the Subterranean Termite (Odontotermes formosanus) Induced by Biosynthesized Zinc Oxide, Titanium Dioxide, and Chitosan Nanoparticles.

Recently, nanoparticles have been widely used in agricultural pest control as a secure substitute for pesticides. However, the effect of nanoparticles on controlling the subterranean termite Odontotermes formosanus (O. formosanus) has not been studied yet. Consequently, this study aimed to evaluate the effectiveness of some nanomaterials in controlling O. formosanus. The results showed that zinc oxide nanoparticles (ZnONPs), titanium dioxide nanoparticles (TiO2NPs), and chitosan nanoparticles (CsNPs) biosynthesized using the culture filtrate of Scedosporium apiospermum (S. apiospermum) had an effective role in controlling O. formosanus. Moreover, the mortality rate of O. formosanus after 48 h of treatment with ZnONPs, TiO2NPs, and CsNPs at a 1000 µg/mL concentration was 100%, 100%, and 97.67%, respectively. Furthermore, using ZnONPs, TiO2NPs, and CsNPs on O. formosanus resulted in morpho-histological variations in the normal structure, leading to its death. X-ray diffraction, UV-vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic light scattering, energy dispersive spectroscopy, and the Zeta potential were used to characterize the biosynthesis of ZnONPs, TiO2NPs, and CsNPs with strong activity against O. formosanus termites. Overall, the results of this investigation suggest that biosynthesized ZnONPs, TiO2NPs, and CsNPs have enormous potential for use as innovative, ecologically safe pesticides for O. formosanus control.

Biocontrol Efficacy of Endophyte Pseudomonas poae to Alleviate Fusarium Seedling Blight by Refining the Morpho-Physiological Attributes of Wheat.

Some endophyte bacteria can improve plant growth and suppress plant diseases. However, little is known about the potential of endophytes bacteria to promote wheat growth and suppress the Fusarium seedling blight pathogen Fusarium graminearum. This study was conducted to isolate and identify endophytic bacteria and evaluate their efficacy for the plant growth promotion and disease suppression of Fusarium seedling blight (FSB) in wheat. The Pseudomonas poae strain CO showed strong antifungal activity in vitro and under greenhouse conditions against F. graminearum strain PH-1. The cell-free supernatants (CFSs) of P. poae strain CO were able to inhibit the mycelium growth, the number of colonies forming, spore germination, germ tube length, and the mycotoxin production of FSB with an inhibition rate of 87.00, 62.25, 51.33, 69.29, and 71.08%, respectively, with the highest concentration of CFSs. The results indicated that P. poae exhibited multifarious antifungal properties, such as the production of hydrolytic enzymes, siderophores, and lipopeptides. In addition, compared to untreated seeds, wheat plants treated with the strain showed significant growth rates, where root and shoot length increased by about 33% and the weight of fresh roots, fresh shoots, dry roots, and dry shoots by 50%. In addition, the strain produced high levels of indole-3-acetic acid, phosphate solubilization, and nitrogen fixation. Finally, the strain demonstrated strong antagonistic properties as well as a variety of plant growth-promoting properties. Thus, this result suggest that this strain could be used as an alternate to synthetic chemicals, which can serve as an effective method of protecting wheat from fungal infection.

Termiticidal, biochemical, and morpho-histological effects of botanical based nanoemulsion against a subterranean termite, Odontotermes Formosanus Shiraki.

Recently, the use of nanopesticides has shown significant efficacy in the control of many pests. However, the effect of nanopesticides, especially nanoemulsions, on suppressing termites, Odontotermes formosanus (Shiraki, 1909) (O. formosanus), has not been studied yet. Therefore, this study aimed to produce nanoemulsions of the essential oils of eucalyptus (Eucalyptus globulus Labill; E-EO) and nutmeg (Myristica fragrans Houtt; N-EO) to suppress O. formosanus. The analysis of eucalyptus nanoemulsion (E-NE) and nutmeg nanoemulsion (N-NE) was confirmed by using UV-Vis, dynamic light scattering, zeta potential, transmission electron microscopy, scanning electron microscopy, and energy dispersive spectroscopy. In addition, chemical analysis by Gas Chromatography with a mass spectrometer (GC-MS) exhibited the major constituents of E-NE and N-NE. The principal chemical components of E-NE included D-limonene, eucalyptol, 1,5-cyclooctadiene,3,4-dimethyl, benzene, and 1-methyl-3-(1 methylethyl)-, while the main constituents in N-NE were cyclohexane,1-methylene-4-(1 methylethenyl)-, eucalyptol, and L-. alpha. -terpineol. The mortality rates were 100% and 99.53%, respectively, after 24 hours of treatment with a concentration of 140 mg/mL, compared to 23.43% and 43.55%, respectively, from E-EO and N-EO treatment. These results refer to the essential oils' nanoemulsion as far more effective than the essential oils themselves. Furthermore, the effects of E-NE and N-NE on detoxification enzymes such as acetylcholinesterase, carboxylesterase, acid and alkaline phosphatase were investigated, as well as total protein concentrations, and the results have been found to be significantly increasing or decreasing in comparison with control. Besides, histological and morphological alterations found post exposure to E-NE and N-NE were shown. Overall, the results from this study clearly indicate that the nanopesticide-formulated nanoemulsions may have great potential to be used as novel, environmentally safe insecticides for controlling O. formosanus.