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Purpose: To evaluate the antidiabetic activity of crude extract of Olea europaea L. (CEOE) leaves in streptozotocin induced-diabetic rats and also to determine its tannin content. Methods: Thirty (30) male, normoglycemic Wistar rats (170 - 250 g) were randomly divided into five groups of six rats each. Group 1, which served as the normal control group, received distilled water while groups 2 and 3, were administered 200 and 600 mg/kg of CEOE extract daily for 18 days, respectively. Group 4 was given glibenclamide (Glibil; 3 mg/kg) while group 5 served as the untreated diabetic control group. Diabetes was induced with a single intraperitoneal injection of streptozotocin (50 mg/kg) and rats with blood glucose levels ≥ 250 mg/dL were confirmed to be diabetic. The blood glucose concentration, water and feed intake, tannin content of CEOE as well as the weight of organs were determined. Results: The results showed that O. europea contained a large amount of tannins (806.22 ± 0.036 μg Tannic Acid Equivalent/g Extract). Administration of the extract (200 and 600 mg/kg) significantly decreased polydipsia and polyphagia, and reversed weight loss in rats with diabetes (p < 0.05 and p < 0.01, respectively) in comparison with glibenclamide. Conclusion: The antidiabetic activity of the crude extract of O. europea was higher than that observed with glibenclamide, thus validating the folkloric use of this plant in diabetes care. Further investigation of Olea europea, including thorough chemical and pharmacological studies, are required. [ABSTRACT FROM AUTHOR]

Fall armyworm, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), is a polyphagous species capable to develop on several cultivated and non-cultivated host plants, including weeds. On this basis, we evaluated the survival and development of S. frugiperda on leaves of hairy fleabane (Conyza bonariensis L.; Asteraceae) and slender amaranth (Amaranthus viridis L.; Amaranthaceae) in laboratory trials. Spodoptera frugiperda neonates were initially fed on leaves of non-Bt maize and then were transferred to hairy fleabane or slender amaranth leaves at different time points. On hairy fleabane leaves, only 12% of larvae in L5 and L6 stages developed into pupae and adults, with similar duration of immature stage of those developed in maize leaves. In contrast, S. frugiperda larvae from L1 to L6 stages developed into pupae on slender amaranth leaves, but only those from the L2 stage onwards originated adults (9–65%). On maize, > 64% of neonates developed to adulthood. Surviving larvae fed on early instars on slender amaranth leaves had up to 10 d longer developmental time of neonate-to-pupa and neonate-to-adult periods compared to those developed on maize. Pupal weights of surviving insects on slender amaranth leaves were also lower (104.9–67.4 mg/pupa) than on maize (207.4 mg/pupa). In summary, our findings indicate that the hairy fleabane is not a suitable host for S. frugiperda, whereas slender amaranth is a viable food source for the survival end development of this species, mainly for advanced instars. [ABSTRACT FROM AUTHOR]