اثر عصاره‌ی آبی (به روش جدید عصاره گیری) چهار گونه ماکروجلبک دریایی قهوه‌ای و قرمز روی کشندگی کنه تارتن دولکه‌ای (Tetranychus urticae Koch)

Marine macroalgae are rich sources of bioactive compounds that are able to produce many types of metabolites with a wide range of biological activities. Extensive studies on the beneficial effects of using seaweed extract on plants, including germination and early establishment of seeds, improving crop yield, increasing resistance to living and non-living stresses, fungal diseases, insect attacks, and increasing useful life after harvest. has shown, but until now, the mortality effects of macroalgae extracts and extract extraction method of this research have not been done on the T. urticae. Four species of Phaeophyta (Padina australis & Cystoseira trinodis) and Rhodophyta (Hypnea flagelliformis & Gracilaria corticata) were collected from the shores of Bushehr in July, 2022 and were identified by the experts of a reputable company and immediately sent to Ardabil for study. After receiving the species, they were washed with distilled water and dried in the shade and then turned into powder. The prepared powders were soaked in distilled water, then placed in a shaker with a revolution (120 rpm), then centrifuged for 20 minutes and in Finally, they were passed through a strainer and the remaining distilled water was evaporated in a sterilized oven and turned into powder. Mortality effects by immersion method of Phaseolus calcaratus leaves in extract concentrations (control (distilled water), 10 mg/ml and 50 mg/ml) and after drying of the leaves, 20 female adult T. urticae were placed on each leaf. The test results showed that all four types of extracts had a significant effect on the mortality of the tartan mite after 72 hours. So that the extracts of 50 mg/ml concentration of P. australis and G. corticata species with an average of 95% lethality, the highest and C. trinodis and H. flagelliformis species with 70% and 68.33% respectively of mortality had the lowest effect in controlling the T. urticae. This research introduces the use of the extract of the four tested species and their extraction method in the biological control programs of this pest with a wide host range, which is very efficient.