بررسی اثر کشندگی عصاره‌ی آبی چهار گونه ماکروجلبک دریایی قهوه‌ای و قرمز روی شته‌ی سبز هلو (Myzuspersicae(Sulzer))

Marine macroalgae contain high amounts of vitamins, minerals, protein, carotenoids, fiber and essential fatty acids. Macroalgae are valuable and have high economic importance due to the fact that they contain valuable polysaccharides such as (agar, carrageenan and alginate). Due to their ability to synthesize phenolic compounds with more rings, these aquatic plants have compounds that cannot be found in land plants. Polyphenols are found in most plants, especially algae, and these compounds are produced to protect against environmental conditions, such as stress and herbivores. In this regard, this research investigated the mortality effect of aqueous extract by soaking the prepared powders in distilled water, then they were placed in a shaker, after that they were passed through a centrifuge and finally through a strainer, and the remaining distilled water was evaporated in a sterilized oven. and turned into powder. Four species of Phaeophyta(Padinaaustralis and Cystoseira trinodis) and Rhodophyta(Hypneaflagelliformis and Gracilaria corticata) marine macroalgae have been studied on M.persicae. Bioassay tests withCapsicumannuum L.leaf immersion method (at control concentrations (distilled water), 10 μl/miland 50 μl/milof each extract) and 20 M.persicaenymphs It was done in three replicates in each Petri dish. The results showed that the highest mortality effect of M.persicaenymph at a concentration of 50 μl/miland after 72 hours in P. australis species with an average of 41.66% and the lowest mortality effect in C. trinodisand G. corticata with an average of 10% observation. The effective substance is affected by various factors such as plant type, living conditions and place, type of solvent, extraction method, etc. Therefore, in order to control the M.persicaewith water extract with a concentration of 50 μl/miland the method of this research, the species P. australis is suggested in combination with other control methods.