Taxonomic notes on some South and Southeast Asian members of the genus Rhene Thorell, 1869 (Aranei, Salticidae, Dendryphantini).

The type materials of seven Indian Rhene species available at the Zoological Survey of India, Kolkata, have been studied. R. mus (Simon, 1889) is illustrated for the first time in 132 years since its first description. Eleven new synonyms and five new combinations are proposed: Zeuxippus Thorell, 1891 syn. n. with Rhene Thorell, 1869; R. biembolusa Song Chai, 1991 syn. n. with R. flavicomans Simon, 1902; R. haldanei Gajbe, 2004 syn. n. with Bianor angulosus (Karsch, 1879); R. decorata Tikader, 1977 syn. n. and R. pantharae Biswas Biswas, 1992 syn. n. with R. pallida (Thorell, 1895) comb. n.; R. citri (Sadana, 1991) syn. n., R. danieli Tikader, 1973 syn. n., R. indica Tikader, 1973 syn. n., R. khandalaensis Tikader, 1977 syn. n. and R. sanghrakshiti Gajbe, 2004 syn. n., with R. flavigera (C.L. Koch, 1846); Rhenefictus tropicus Logunov, 2021 syn. n. with Rhenefictus wandae (Wang Li, 2021) comb. n. (ex. Rhene), Rhene atellana (Thorell, 1895) comb. n., Rhene histrio (Thorell, 1891) comb. n., Rhene pallida (Thorell, 1895) comb. n., and Rhene yunnanensis (Peng Xie, 1995) comb. n. (all ex. Zeuxippus). Detailed digital illustrations and distributional maps are also provided.

Development of encapsulated peppermint essential oil in chitosan nanoparticles: characterization and biological efficacy against stored-grain pest control.

Peppermint oil (PO) has widely been reported for their nutritional and biomedical properties. Essential oil (EO) has several properties, usage restricted due to environmental condition, polymer based nanoencapsulation of EOs is developed as one of the promising technique to address this limitation. In this current study emphasizes on developing Peppermint oil (PO) encapsulated chitosan nanoparticles (CS NPs) by ionic gelation method in order to improving its insecticidal potential effective management of two stored grain pest. The nano-encapsulated PO (CS/PO NPs) was confirmed by UV-Vis spectrophotometry and X-ray diffraction (XRD) techniques. The physicochemical characterization of CS/PO NPs revealed <563.3 nm size, Zeta potential of -12.12 mV, encapsulation efficiency >64% and loading capacity >12.31% respectively. Developed CS/PO NPs demonstrated the toxicity studies have significantly efficacy against both stored product pest compared to control. In-vivo percent inhibition of AChE activity ranged between S. oryzae (52.43% and 37.71% and and T. castaneum (37.80% and 31.29). Overall, these results highlighted that polymer chitosan nanoparticle encapsulated with essential oil is a promising novel design that could be promoted in stored food pest management schedule for T. castaneum and S. oryzae.

Structural characterization of chitosan nanoparticle loaded with Piper nigrum essential oil for biological efficacy against the stored grain pest control.

In this study, Piper nigrum essential oil (PNO) has been encapsulated in chitosan nanoparticle (CS NPs) via ionic gelation method with sodium tripolyphosphate (TPP). The successfully loaded Piper nigrum EO was confirmed by UV-Vis spectrophotometry and X-ray diffraction (XRD) techniques. The average particle size of P. nigrum essential oil loaded chitosan nanoparticle (CS/PNO NPs) showed 527.5 nm with spherical shape morphology. Zeta potential values of the particles were found to be negative -5.34 mV. Encapsulation efficiency and loading efficiency was in the range of 35% to 40% and 4.85% to 7.04% respectively. CS/PNO NPs exhibited strong insecticidal activity against Sitophilus oryzae and Tribolium castaneum. In addition, CS/PNO NPs enhanced the fumigant toxicity and altered the neurotransmitter, acetylcholine in both the stored grain pests. Overall results of nanoformulation indicated that these novel design systems could be promoted in integrated pest management schedule for T. castaneum and S. oryzae.

Toxicity, antifeedant and biochemical efficacy of Mentha piperita L. essential oil and their major constituents against stored grain pest.

The efficiency of chemically characterized Mentha piperita L. essential oil (EO), a plant based insecticide was tested for acetylcholinesterase activity (AChE) and antioxidant enzyme system (SOD, CAT, GSH and GSSH) in Sitophilus oryzae (L.) and Tribolium castaneum (Herbst.). GC-MS results evidenced for menthone and menthol as the major compounds of EO. As a fumigant, EO and its major component showed 100% mortality at 75.0 µL/L air and 100.0 µL/L air against S. oryzae and T. castaneum at 24 h of exposure. Antifeedant activity exhibited 100% lethal activity against pests in comparison to sub lethal doses. In vivo percent inhibition of AChE activity ranged between S. oryzae (29.68%, 18.81% and 14.34%) and T. castaneum (20.67%, 13.73% and 9.19%). Significant changes in antioxidant defense system studied for SOD, CAT, GSH and GSSH were noticed. Results revealed the toxicity of EO associations with the inhibition of AChE activity accompanied by oxidative imbalance. Therefore, M. piperita EO has a noteworthy role in insecticidal properties and could be recommended as an eco-friendly alternative to synthetic insecticides.