Toxicity and Biochemical Effects of Spirotetramat and its Binary Mixtures with Nanosilica against Aphis gossypii Glover, Bemisia tabaci Gennadius and the Earthworm, Eisenia fetida

Abstract

Nanotechnology will make agriculture eco-friendly and profitable by reducing the concentration of insecticides used, which is appreciable from the environmental safety perspective. Toxicity of spirotetramat alone and its mixtures with nanosilica against nymphs of Aphis gossypii (Hemiptera: Aphididae) and adults of Bemisia tabaci (Hemiptera: Aleyrodidae) was evaluated through laboratory and field experiments during two years (2020 and 2021). The possible impact of treatments on Eisenia fetida (Oligochaeta: Lumbricidae) was also assessed. The enzymatic activity of carboxylesterase (CarE) and glutathione S-transferase (GST) in tested insects and earthworm was estimated. Toxicity of spirotetramat was increased when mixed with nanosilica at 250, 500, 1000 mg L -1 , ratios were 1.13, 1.91 & 2.59 -fold on A. gossypii, 1.12, 1.41 & 2.26 -fold on B. tabaci and 1.05, 1.17 & 1.46 -fold on E. fetida, respectively. Spirotetramat and nanosilica at 1000 mg L -1 mixture gave the highest significantly increased in CarE activity of A. gossypii and B. tabaci (11.42 and 9.33 μmol min -1 mg protein -1 ), and decreased the GST activity (1.54 and 1.69 μmol min -1 mg protein -1 ), respectively, relative to the control. While, the same previous mixture on E. fetida increased the enzyme activity of CarE and GST (13.37 and 3.36 μmol min -1 mg protein -1 ), respectively, compared to the control. Additionally, the mixture of spirotetramat and nanosilica at 1000 mg L -1 recorded the highest population reduction percentages in A. gossypii (92.5 and 95.5 %) and B. tabaci (79.9 and 84.4 %) compared with spirotetramat alone (88.6 and 90.7%) for A. gossypii, (73.6 and 78.9%) for B. tabaci during 2020 and 2021 cotton seasons, respectively.

Synthesis of Tungsten Oxide, Iron Oxide, and Copper-Doped Iron Oxide Nanocomposites and Evaluation of Their Mixing Effects with Cyromazine against Spodoptera littoralis (Boisduval)

“… 27 The bioapplications based on magnetic NPs have gotten special attention because they have prominent advantages over other materials in terms of cost and ease of manufacture, physical and chemical stability, biocompatibility, and environmental safety, as well as the ability to be tuned and functionalized for specific applications. 28 Metal oxide NPs such as zinc oxide, 29 titanium dioxide, 30 silicon oxide, 31 , 32 iron oxides, 33 , 34 copper oxide, 35 and tungsten oxide 36 are also low-cost materials, easy to produce, and chemically stable. As a result, these nanomaterials are excellent candidates for various applications, including water treatment, 37 antimicrobials, 38 sensors, and many more.…”

Chitinase of Trichoderma longibrachiatum for control of Aphis gossypii in cotton plants

“…Cotton ( Gossypium hirsutum L.) is an important cash crop and is highly susceptible to attack by aphids 6 . Cotton aphids ( Aphis gossypii ), as a vicious pest of cotton that usually suck the phloem sap from vascular plant parts of cotton and help in the transmission mechanism of more than 75 viruses 7 , 8 . Major damages caused by A. gossypii are associated with its remarkable deposition of sooty mold and secretion of honeydews on cotton balls 9 , 10 .…”