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This study focused on encapsulation of Rosmarinus officinalis essential oil (EO) on chitosan and gum Arabic matrix in various ratios and with varying essential oil concentrations. Additionally, UV/VIS spectroscopy was used to determine cumulative-release profiles. The insecticidal activity was tested against Tribolium castaneum and Oryzaephilus surinamensis, both pests of stored products. In terms of encapsulation efficiency (EE%) and loading capacity (LC%), capsules had EE at 45.8% and LC at 2.31%. Furthermore, many minor compounds were lost after encapsulation, until identifying only 1,8-cineole, α-terpineol, and camphor after 60 d of storage. The fumigant tests demonstrated that encapsulated EO exhibited an effective control against insect pest during storage periods, namely, 30, 45, and 60 d with 99, 66, and 46% mortality for T. castaneum and 100, 84, 82% mortality for O. surinamensis. [ABSTRACT FROM AUTHOR]

The aerial parts of cypress (Cupressus sempervirens L.) of three collect regions (Bizerte, Ben-Arous and Nabeul) were reported for their essential oil (EO) compositions, antioxidant, antimicrobial and insecticidal activities. Results showed that the higher EO yields were observed in Bizerte and Ben Arous (0.56%), followed by Nabeul (0.49%). The EO composition showed the predominance of α-pinene with 36.72% in Bizerte, 30.22% in Nabeul and 30% in Ben-Arous. Cypress EO of Bizerte showed higher antiradical capacity (IC50 = 55 µg/mL) than Ben-Arous (IC50 = 97.50 µg/mL) and Nabeul (IC50 = 155 µg/mL). E. faecalis was the most sensitive strain to cypress EO of Bizerte with the largest inhibition zone (IZ = 65 mm). Regarding the insecticidal activity, cypress EO of Bizerte had the highest mortality of Tribolium castaneum with a lethal concentration of LC50 = 164.3 µL/L air after 24 h exposure. [ABSTRACT FROM AUTHOR]

Eucalyptus leucoxylon, Rosmarinus officinalis, berries, and leaves of Schinus molle essential oils were analysed using GC-MS techniques and assessed for their fumigant toxicity against adults, larvae, and eggs of Ectomyelois ceratoniae and Ephestia kuehniella. Results showed that E. leucoxylon contained Spathulenol, p-Cymene, and Cryptone as major compounds. GC – MS analyses showed that the major compounds of R. officinalis essential oil were 1,8-Cineole, Camphor, and α-pinene. I-Phellandrene, t-Muurolol, and Phellandrene were the major components of the S. molle leaves; while I-Phellandrene, Limonen, and δ-Cadinene were the major components of the S. molle berries. S. molle berries were the most efficient followed by R. officinalis against E. ceratoniae and E. kuehniella. The most effective tested essential oil against E. ceratoniae larvae was S. molle berries. Results on the ovicidal and larvicidal effects of the tested oils demonstrated that R. officinalis was the most effective essential oil against E. kuehniella eggs. [ABSTRACT FROM AUTHOR]

This research was conducted to determine the effect of geographical distribution on morphological characteristics of plants and some chemical compounds such as polyphenols. Moreover, we explore the contact toxicity of ethanolic and methanolic extracts from Urginea maritima bulbs and Asphodelus microcarpus tubers collected from three localities in the North West of Tunisia against Tribolium castaneum adults. The toxicity results demonstrated that both of the studied plant extracts had an effective control against T. castaneum at concentration 7.5 µL/L air, thus total mortality reached. In addition, results showed plant extracts with methanol exhibited high mortality percentage of T. castaneum. On the other hand, results revealed that chemical composition of U. maritime bulbs and A. microcarpus tuber extract depends on the soil components and geographical distribution of plants. The present investigation confirmed that A. microcarpus and U. maritima may be recommended as an eco-friendly alternative to synthetic insecticide against T. castaneum. [ABSTRACT FROM AUTHOR]

The phytochemical composition of Laurus nobilis essential oil and their anticholinesterase, antioxidant, and insecticidal potential were studied. Also, the oil volatile fraction was compared in semolina at the beginning and after storage periods. For that, a headspace solid-phase-microextraction analysis (HS-SPME) coupled with gas chromatography and mass spectrometry was undertaken. Significant quantitative and qualitative differences of the oil volatile fraction were detected according to storage periods and occupation space ratios. Additionally, anti-acetylcholinesterase activity of L. nobilis oil against T. castaneum adults was evaluated. Results revealed that insecticide activity varied according to storage duration and occupation space. Besides, the oil acts on acetylcholine hydrolysis by inhibiting the activity of acetylcholinesterase. These results highlighted that L. nobilis essential oil may be recommended as an eco-friendly alternative for preserving semolina during storage. [ABSTRACT FROM AUTHOR]

Natural insecticidal products, essentially essential oils and their bioactive compounds are available as an excellent alternative method to control insect pests as well as they are less toxic to human health. However, due to their volatile constituents, encapsulation could be considered as the most suitable solution for their practical application. Therefore, this study aims to explore the insecticidal toxicity of chitosan nanoparticles loaded with Rosmarinus officinalis essential oil against adults of Carpophilus hemipterus. Chitosan nanoparticles were prepared by ionic gelation method with an encapsulation efficiency 41.543.1% and loading capacity 5.24G0.28%. Results revealed that chitosan nanoparticles loaded rosemary oil exhibited interesting insecticidal toxicity towards C. hemipterus adults in stored dates with 50.73% mortality. Overall, this work pointed out that the innovative design method based on chitosan-nanoparticles loaded rosemary oil can be promoted in integrated pest management program for stored date pests. [ABSTRACT FROM AUTHOR]

A three years survey and monitoring studies (2013–2014–2015) were carried out through 4 regions of north Tunisia in order to follow the evolution of the distribution, the frequency of occurrence and damage caused by the Hessian fly Mayetiola destructor (Say) to bread wheat (Triticum aestivum L.) and durum wheat (Triticum durum Desf). Moreover, the effectiveness of resistance genes H3, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H22, H23, H25 and H26 to protect wheat from Hessian fly attack was assessed in natural field and under controlled laboratory conditions at INRAT‐Kef Station. Results showed that Hessian fly was detected in 60.33% and 51.5% of all sampled durum and bread wheat fields, respectively. This pest was more frequent with a higher percentage of infestation in semi‐arid regions. Indeed, during 2013, infestation rate attained 12.39% in Kef region against 0.9% registered in Bizerte region. In order to update information about the annual number of generations, we surveyed the population dynamic of Hessian fly in Kef region. Three generations of the fly were counted annually on wheat, with two complete and one incomplete generation. This insect affects host plant growth at different developmental stages. Plant height was the most affected parameter followed by shoot dry weight and tiller number. Field investigations on host resistance revealed that among the 16 tested resistance genes, and only three were strictly effective (H22, H25 and H26). The resistance genes H5, H9, H13 and H9H13 have also conferred high levels of protection against Hessian fly. This work indicated that H22, H25 and H26 genes could be incorporated into Tunisian wheat varieties and released to farmers to manage the threat due to Hessian fly attacks. [ABSTRACT FROM AUTHOR]