Acaricidal Impacts of Two Algae on Tetranychus urticae Koch (Tetranychidae) in Laboratory and Semi-Field Conditions

Tetranychus urticae Koch (Acari: Tetranychidae) is the most common mite in greenhouses and on field-grown crops, causing significant damage to a variety of crops. Traditional agricultural practices, such as the use of synthetic pesticides, cause a variety of difficulties, including environmental contamination, pest resistance, and adverse impacts. As a result, these detrimental consequences have highlighted the need for new efficient, safe, and environmentally friendly natural alternatives to synthetic pesticides. Algal products serve an important role as chemical alternatives in agricultural applications. The current study is to bioassay biocide effects of two commercial algal products (marine algae and veggie) as natural and safe bio-pesticides on T. urticae under laboratory and semi-field conditions. The findings showed that mortality increased as concentration and time increased. A marine alga is more efficient than veggie, after 7days of exposure to T. urticae adult females, LC50 values were 0.429 and1.369 g/l, respectively. Also, the LC50 values for marine algae and veggie for treated eggs of T. urticae were 1.69 g/l and 2.57 g/l, respectively under laboratory conditions. The reduction percentage of T. urticae immature stage after 14 days of application with marine algae and veggie were 89.81 and 88.67%, respectively.