The stem borer, Lixus algirus L. (Coleoptera: Curculionidae) is the major insect pest of faba bean in the Mediterranean region. This study investigates the field biology and fluctuation of L. algirus at Douyet research Station in Morocco during two cropping seasons 2014-2015 and 2015-2016 using two local faba bean varieties. The influence of sowing dates and varieties on the damage caused by L. algirus was investigated over different locations and seasons using a split-plot design. The overwintering adults appear in the field from February by feeding over the leaves of faba bean plants. Eggs are laid from Mid-February through late April and mostly during March. The egg peak ranged from 0.75 to 1.1 eggs per plant. The number of larvae increases during March and peaked in April. The larval peaks ranged between 0.45 to 1.5 larvae per plant. The larval development takes an average of 42 days. Pupation lasts about 21 days within stems. Adults emerged in early June. Life cycle duration was 80 days. One generation of L. algirus was recorded on faba bean varieties in Morocco. The mean number of eggs showed a positive correlation with total rainfall. The number of pupae and relative humidity was negatively correlated. Peach and almond leaves were the most preferred by the newely emerged L. algirus adult during the summer and early autumn period. Planting dates did not affect L. algirus infestation levels over all varieties tested and locations.

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Après son introduction en 2008, Tuta absoluta (Meyrick) a causé des graves dommages à la production de tomates au Maroc. La lutte chimique est une méthode rapide et simple pour empêcher le développement de ce ravageur. Cependant, l'utilisation massive de ces produits chimiques présente des risques potentiels pour la santé et l'environnement. Afin de prévenir cet inconvénient, cette étude est un essai pour fournir des alternatives basées sur l'utilisation des bioinsecticides d'origine végétale qui sont des produits naturels. Sept plantes marocaines (Thymus vulgaris, Ononis natrix, Lawsonia inermis, Ricinus communis, Argania spinosa, Urtica dioica et Peganum harmala) ont été collectés dans différentes zones de la vallée du Souss. Les matières actives ont été extraites en utilisant un évaporateur rotatif (40°C) et du méthanol comme solvant. La méthode du « Leaf dip bioassay » a été adoptée pour évaluer la toxicité in vitro de ces extraits végétaux contre les larves L2 de T. absoluta. Le logiciel POLO‐PC a été utilisé pour déterminer la dose létale pour 90% des larves (DL90). L'extrait de T. vulgaris a affiché le taux de mortalité le plus important (97%), suivi par R. communis, P. harmala et U. dioica é qui affichaient respectivement des taux de mortalité de l'ordre de 80%, 65% et 55%. La DL90 la plus faible a été obtenue avec l'extrait de T. vulgaris (156 023 ppm).

The stem borer weevil, Lixus algirus L. (Coleoptera: Curculionidae), causes severe damage to faba beans (Vicia faba L.) in Morocco. A survey was conducted to determine the distribution of L. algirus, its natural enemies, and the severity of damage it causes to faba beans in Morocco. A total of 16 and 27 stops were randomly selected and surveyed in the major faba bean-growing regions during the years 2017 and 2018, respectively. The Gharb region recorded the highest level of L. algirus infestation at 80% and 71.42% in 2017 and 2018, respectively, followed by the Saïs region at 58.75% and 36% in 2017 and 2018, respectively. Two egg parasitoids (Chlorocytuslixi and Anaphes longicornis), one egg predator (Orius sp.), and a larval parasitoid (Cyanopterobracon) were identified. The ectoparasitoid C. lixi was observed to be the most dominant species, with percentages of parasitism in the regions ranging between 35.75% and 70.49%. The larval parasitoid Cyanopterobracon was the second most abundant species, with percentages of parasitism ranging between 3.03% to 15.96%. Understanding the parasitoid complex of L. algirus in Morocco is necessary for the subsequent development of a biological control program.