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Abstract:There is a growing interest of industry to replace synthetic chemicals by natural products with bioactive properties from plant origin. The aim of this study was to validate the therapeutic properties of Mentha pulegium L. by conducting a phytochemical study, to determine the chemical composition of its essential oils (EO) and evaluate its insecticidal activity against stored cereals pests. Leaves and flowers of M. pulegium L.were collected from three regions of the Moroccan Middle Atlas. Phytochemical tests on pennyroyal aerial parts revealed the presence of gallic tannins, flavonoids, alkaloids, sterols and triterpenes and saponins. The chemical composition of essential oils was analyzed by gas chromatography coupled with mass spectrometry. The main components were pulegone and piperitenone. The EO from Khénifra is dominated by pulegone (81.46%), and those from Azrou and M'rirt are rich both in pulegone (68.86 and 71.97%) and piperitenone (24.79% and 26.04%) respectively. Pennyroyal oil has showed an important fumigant effect against Sitophilus oryzae (L.) adults. This effect is influenced by the tested doses and exposure periods. The potential of this plant to be used to control stored product insects was discussed.

Control methods used to limit field losses caused by Bruchus rufimanus Boheman, 1833 consist of synthetic insecticides that pose health risks to farmers, consumers and the environment. In an attempt to find safer alternatives, we screened essential oils from the leaves of Rosmarinus officinalis collected in the Middle Atlas and Loukkos regions of Morocco in the laboratory as natural fumigants against B. rufimanus. These essential oils were extracted by steam distillation using a Clevenger distiller, characterised chemically by coupled gas chromatography–mass spectrometry (GC/MS) and tested at five concentrations (0, 10, 20, 40, 80 µl/l air). The essential oils of R. officinalis mainly comprised oxygenated monoterpenes (Middle Atlas: 79.4%; Loukkos: 48.78%) and terpenes (Middle Atlas: 14.71%; Loukkos: 32.33%). The lethal concentrations (LC50) of Middle Atlas and Loukkos essential oils against male beetles ranged from, respectively, 46.53 to 1.19 µl/l air and 58.85 to 11.57 µl/l air. Similarly, doses of R. officinalis essential oils from Middle Atlas and Loukkos lethal to females, ranged from 44.6 to 2.08 µl/l air and from 53.00 to 5.38 µl/l air, respectively. Additionally, the lethal time (LT50 and LT99) of exposed adults ranged from 1–8 and from 2–13 days for different concentrations of R. officinalis essential oils from Middle Atlas and Loukkos, respectively. With no mortality recorded in the control groups, these findings demonstrate the fumigant potential of these oils against this bruchid under the storage conditions.

To develop eco-friendly alternative control strategies for medfly, mass trapping trials were conducted in the central Morocco during the crop season 2016. Two control methods, mass trapping and the attract-and-kill technique were compared for the control of medfly on two peach varieties (?Rome Star? and ?Ryan Sun?) in Sefou district. For mass trapping, 62 traps/1.23 ha of MagnetTMMed type baited with ammonium acetate, trimethylamine, putrescine and 0.01 g of deltamethrin were installed on both varieties. In plots testing the attract-and-kill technique, treatments with malathion in mixture with protein hydrolyzate were applied to straw tufts attached to branches of the same varieties whenever 1 fly was caught on a Trimedlure trap installed at the center of each plot. The results showed that the number of flies captured by mass trapping reached 508 and 489 adults on ?Rome Star? and ?Ryan Sun?, respectively. The average number varied from 1 to 3 adults/trap/day, depending on the date of capture and the variety, and females accounted for 62-100% of total caught flies. In plots protected by the attract-and-kill technique, and taking into account the threshold adopted by the farm, 11 and 15 treatments were carried out respectively on the ?Ryan Sun? and ?Rome Star? varieties. Overall, infestation rates in plots did not exceed 0.3% before or at harvest with mass trapping versus 0.9% with the attract-and-kill technique. On fruit dropped on the ground, the infestation rate did not exceed 4% in mass trapping, compared to 11.5% in the chemically treated plots. Mass trapping was therefore proved to be an effective and eco-friendly tool for managing medfly on peach fruit.

Des élevages expérimentaux de Callosobruchus maculatus (F.) (Coleoptera, Bruchidae) sur les graines de Vicia faba décortiquées ou non, ou sur des pastilles faites des mêmes graines, ont permis de mettre en évi-dence une barrière empêchant le développement de la bruche.Avec les graines entières, toutes les larves meurent au premier stade enfoncées dans le tégument; alors qu'elles se développent normalement dans les graines décortiquées.Avec des pastilles de broyats de graines non décortiquées, la majorité des larves meurt avant le terme de leur développement; la plus forte mortalité est observée au quatrième stade larvaire. Les larves, qui survivent, accusent une augmentation de leur durée de développement par rapport à ceIles qui se nourrissent aux dépens des pastilles faites de graines sans tégument.