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The Opuntia ficus-indica (L.) cactus, a crucial crop in Morocco, is threatened by the wild cochineal, Dactylopius opuntiae (Cockerell). The aim of this research was to investigate the efficacy of nine bacterial strains against both D. opuntiae nymphs and adults females applied individually or after black soap in the laboratory, greenhouse, and field conditions. Using the partial 16S ribosomal DNA, the bacterial isolates were identified as Pseudomonas koreensis, Pseudomonas sp., Burkholderia sp. and Bacillus sp. Under laboratory conditions, the insecticidal activity of P. koreensis strain 66Ms.04 showed the level mortality (88%) of adult females' at 108 CFU/mL, 7 days after application. At a concentration of 108 CFU/mL, P. koreensis strain 66Ms.04 and Pseudomonas sp. (strains 37 and 5) caused 100% nymphs mortality rate three days after application. Under greenhouse conditions, the use of P. koreensis strain 66Ms.04 at 108 CFU/mL following the application of black soap (60 g/L) demonstrated the maximum levels of females and nymphs' mortalities with 80 and 91.25%, respectively, after 8 days of treatment. In field conditions, the combined application of the P. koreensis strain 66Ms.04 at 108 CFU/mL with black soap at 60 g/L, for an interval of 7 days, significantly increased the mortality of adult females to 93.33% at 7 days after the second application. These findings showed that the combined treatment of P. koreensis strain 66Ms.04 with black soap can be a potent and eco-friendly pesticide against D. opuntiae. [ABSTRACT FROM AUTHOR]

Hessian fly, Mayetiola destructor (Say) is a destructive insect pest occurring in many wheat growing areas of the world. The most effective management option for controlling Hessian fly is the use of resistant wheat cultivars carrying specific resistance genes. However, wheat resistance genes to Hessian fly are affected by temperature. Two Moroccan cultivars 'Chaoui' and 'Marouane' and three ICARDA elites DWHF01, DWHF02 and Icamoram7 all carrying resistance to Moroccan Hessian fly populations were evaluated at three different temperatures (20, 25 and 30 °C). Results showed that the elite DWHF01 and DWHF02 resistance was less affected by higher temperatures with percentage of resistant plants remaining above 60% at 30 °C. However, 'Marouane', 'Icamoram7' and 'Chaoui' lost more than 50% of their resistance at 30 °C. Resistance in all these genotypes was expressed only as antibiosis with presence of dead first instars on resistant plants. The number of live larvae on susceptible plants was counted and larval density decreased with increasing temperature. Moreover, length measurements of live larvae showed significant differences across different temperatures, the size of larvae increased as temperature increased and ranged between 3.23 and 4.13 mm. In light of the warming climates and increase occurrence of days above 30 °C during the first months of the Moroccan wheat season, the data presented here are meant to help breeders recommend cultivars better adapted to the raising temperatures. [ABSTRACT FROM AUTHOR]

This study investigates the insecticidal effect of the essential oil of Mentha pulegium L. on the second and third instar larvae of Helicoverpa armigera (Hübner). Antifeedant, contact toxicity and systemic toxicity of M. pulegium essential oil were evaluated using four concentrations and an untreated control under laboratory conditions. M. pulegium essential oil showed high level of antifeedant activity at 74.15%, and 61.72% when applied on the second instar larva and third instar larvae, respectively. The second instar larva was also more susceptible to systemic toxicity than the third instar larva LC50 1.80% and 3.80% at 24 h, respectively. Contact toxicity induced with LC50 values of 1.31% and 1.085% after 3 and 6 h on the second instar larva, respectively, and with LC50 values of 2.39% and 2.33% after 3 and 6 h on the third instar larva, respectively. This study showed that there is potential for using M. pulegium essential oil to formulate a biopesticide for the control of H. armigera larvae on chickpea. [ABSTRACT FROM AUTHOR]