The South American tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), invaded Algeria in 2008 and caused severely significant devastation to tomato plants. This study designed to ...evaluate the thermal requirements and assess the influence of temperature on the life cycle of this devastating pest under controlled greenhouse environment. Through a series of experiments, we observed four generations of T. absoluta at various temperatures and relative humidity levels. We chased the population dynamics by using pheromone traps and revealed four overlapping generations, each of which corresponded to peaks in adult flying activity. These peaks were influenced by the greenhouse's temperature and humidity levels. The development of successive and overlapping generations of T. absoluta requires temperatures ranging from 25 to 30 °C, coupled with humidity levels between 58.5 % and 69.33 %. Additionally, the morphometric analysis of T. absoluta larvae allowed the identification of four larval stages characterized by lengths of 2.5 mm for the first instar, 2.5 to 4 mm for the second instar, 4.5 to 5.5 mm for the third instar, and 6 to 7 mm for the fourth instar. By studying the biology of T. absoluta and its thermal and hygrometric requirements, we can develop an integrated pest management strategy that efficiently battles against this destructive pest.
The stinging nettle (Urtica dioïca L.) has been used as a traditional remedy to treat an important range of diseases due to its therapeutic virtues. This work was undertaken to valorize the ...prospective of extracts of wild Urtica dioica of Algeria as sources of polyphenols and natural antioxidants, as well as the effectiveness of diverse extraction techniques (Soxhlet and maceration) and solvents (ethanol and hexane) on the content of secondary metabolites, and their antioxidant activity were examined by Folin-Ciocalteu, DPPH, FRAP and TAC essays, respectively. The phytochemical screening of aerial part of Urtica dioïca revealed the presence of bioactive compounds: flavonoids, phenols, tannins, anthocyanins and saponosides. Soxhlet with ethanol extracts of Urtica dioica indicated the highest values of total phenolic (13.35 ± 1.06 mg GAE / g DW), flavonoids (3.61 ± 0.46 mg QE / g DW), and tannin (5.37 ± 0.59 mg CE / g DW). Similarly, In terms of IC50, the results clearly showed that the technique of Soxhlet with ethanol was the strongest radical scavenger (0.343 ± 0.012 mg/ml). On another hand, maceration with hexane extracts represented the lowest contents of polyphenols compounds and the antioxidant activity. Subsequently, Soxhlet associated with ethanol exhibited the highest extraction ability for isolation of bioactive ingredients from wild Urtica dioica.
The objective of this study was to investigate the possible protective role of nettle Urtica dioica (UD) against Hg-induced toxicity.
A total of 28 rats were equally divided into four groups: the ...control, the Hg (0.8 g HgCl2/kg in the diet), the UD (1.5 ml UD/rat by gavage), and the Hg+UD group. HgCl2 was daily dissolved in distilled water and immediately mixed with the standard diet. A solution of daily infused fresh nettle leaves in boiling water (16 g in 25 ml) was obtained and then it was administrated by gavage. Biochemical and reproductive markers, in addition to glutathione (GSH) level (liver, kidney and testis) and the histological profiles (testis and epididymis) were evaluated after 1 month exposure.
Compared to the control, the levels of glucose, triglycerides, urea, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were significantly raised in the Hg group. In the latter group, the concentrations of Mg, Fe, and Ca were significantly decreased. Besides, Hg+UD group has only showed raised AST activity and reduced Mg level. Concerning the fertility markers, Hg has provoked a significant decrease in the spermatozoa's concentration and motility and in plasma testosterone level as well. Furthermore, hepatic, renal and testicular GSH concentrations have declined significantly in the Hg treated rat compared to the control. A remarkable enhancement of the GSH level was observed in all organs of the UD group. The histological examinations of the Hg group have revealed marked testicular degeneration of the most seminiferous tubules, and showed few sperms in the lumen of epididymis ducts. However, the Hg+UD rats have demonstrated an improved histological structure with the presence of important numbers of sperms in the lumen. In addition, a clear stabilization of organized seminiferous tubules and an increased sperms' numbers were noted in the UD supplemented rats.
Nettle leaves have not only played a clear protective role during Hg intoxication, but it also enhanced hepatic, renal and testicular GSH level of Wistar rats.
Stored grain insects have revealed resistance to synthetic insecticides, a fact that has encouraged the use of medicinal plants for integrated pest control. Pistacia lentiscus is a plant from the ...Anacardiaceae family, very widespread in the Mediterranean region, and one of the most important medicinal plants in Algeria. This present study was undertaken to evaluate the potential of extracts of P. lentiscus from Algeria as sources of total phenolic (TPC) and total flavonoid (TFC) contents, as well as the efficiency of the insecticidal effect of methanol extracts (MeOH) extracted from various parts of P. lentiscus against Sitophilus granarius (L.), by using ingestion and contact toxicity methods. Leaves extracts of P. lentiscus had depicted the highest concentration of TPC and of TFC (384.05 ± 8.21mg GAE/g; 165.60 ± 0,00 mg of RU/g of dry weight DW.), respectively. Furthermore, leaves extracts of P. lentiscus have demonstrated the greatest insecticidal result compared to other parts of the plant which is explained by the causing the mortality of adult S. grinarius with a value of 98.82 % and LC50 of 83.35 µg/L via a significant reduction in the number of individuals in a dose-dependent. P. lentiscus extracts have the potential to be an effective natural agent against stored-product insects and could be an alternative environmentally friendly bio-insecticide.
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