JOURNAL OF ANALYTICAL SCIENCES AND APPLIED BIOTECHNOLGY An International Open Access, Peer Reviewed Research Journal ISSN: 2665-8488 2019, Vol. 1, Issue (1) Pages: 1-10 ----------- (* ) Corresponding author: Ayoub AINANE Tel.: +212672349724; E-mail address: ainane.ayoub@gmail.com Evaluation of the toxicity of the essential oils of certain mints grown in the region of Settat (Morocco): Mentha piperita, Mentha pulegium and Mentha spicata against, Sitophilus Granarius, Sitophilus Oryzae and Sitophilus Zeamais Ayoub AINANE a *, Fatima KHAMMOUR a , M’hamed EL KOUALI a , Mohammed TALBI a , Adyl OUSSAID b , Adil LEMHIDI b , Abdelouahad OUSSAID b , Tarik AINANE c a LCAPCM, Faculty of Sciences Ben Msik, University of Hassan II, BP 7955,Casablanca 20660, Morocco. b Faculty Multidisciplinary University Mohammed Premier B.P: 300, Selouane 62702 Nador Morocco c Superior School of Technology (EST-Khenifra) ,University of Sultan Moulay Slimane, PB 170, Khenifra 54000 Morocco. ARTICLE INFO Received February 25 th ,2019 Received in revised form April 25 th ,2019 Accepted Jun 1 st , 2019 ABSTRACT Essential oils are secondary metabolites produced by plants as a defense against phytophagous pests. These extracts contain complex compounds. The essential oils present many previous works, especially in Morocco. The present work is a continuation of chemical study of the essential oils of some mints grown in the Settat Morocco region: Mentha piperita, Mentha pulegium and Mentha spicata, against insects of cereals: Sitophilus Granarius, Sitophilus Oryzae and Sitophilus Zeamais. Experiments were conducted in the laboratory using different doses of these oils to evaluate the mortality they cause on the adults of the insects tested. The results of the sensitivity showed that the three essential oils of mint had important insecticidal properties against the pests studied. And as a result, they were able to destroy all the insects at a concentration of 2 μl/cm 3 for a duration of 24 hours of treatment. © 2019 EST-Khenifra, University of Sultan Moulay Slimane. All rights reserved. Keywords: Mentha, Essential oils, Sitophilus, Insecticidal activity. 1. Introduction: The development of chemistry has given birth to synthetic methods for insect protection of stocks have the use of chemical insecticides. However, the search for alternatives is essential. It is in this context that it is the use of essential oils in the protection of stocks as bio insecticides with properties that respect the environment. The beetle’s pests of mostly beetle commodities can cause the total loss of a stock. as well the beetles are the most damaging pests of the grain stocks that for many developing countries represent the bulk of the diet that supports more than 70% of the population [1]. 2. Material and methods: 2.1. harvesting, extraction and analysis by gas chromatography (GC) / mass spectrometry (MS): The methods of harvesting the plants studied and the extraction of essential oils and the analysis of the oils by gas phase chromatography coupled with mass spectrometry are indicated in the first worked (see back articles) [2]. 2.2. The insects studied: 2.2.1 Sitophilus granarius: Sitophilus granarius, also known as wheat weevil, is a species of beetle’s insects of the family of Curculionidae with an almost cosmopolitan distribution. [3]. Adults are small, uniformly dark brown beetles about 5 mm in length, unable to fly. These larvae, white and legless, develop inside the grains.