Acarological Society of Iran Persian Journal of Acarology 2251-8169 10 3 2025 12 01 Laboratory bioassay of six pesticides, an entomopathogenic fungus,and a botanical pesticideon two-spotted spider mite,Tetranychus urticaeKoch(Acari: Tetranychidae) 269 280 238635 10.22073/pja.v10i3.65092 EN Rumpa Basak Laboratory of Applied Entomology and Acarology, Department of Entomology, Bangladesh Agricultural University, Bangladesh; Mahbuba Akter Laboratory of Applied Entomology and Acarology, Department of Entomology, Bangladesh Agricultural University, Bangladesh; Toufica Ahmed Tumpa Laboratory of Applied Entomology and Acarology, Department of Entomology, Bangladesh Agricultural University, Bangladesh; Dilruba Sharmin Laboratory of Applied Entomology and Acarology, Department of Entomology, Bangladesh Agricultural University, Bangladesh; Mohammad Shaef Ullah Laboratory of Applied Entomology and Acarology, Department of Entomology, Bangladesh Agricultural University, Bangladesh; Journal Article The two-spotted spider mite, <em>Tetranychus urticae</em> Koch (Acari: Tetranychidae) is a serious pest that infests different agricultural crops in Bangladesh. The application of different types of pesticides (botanical and chemical) with various modes of action and bio-pesticides was used for the first time to develop sustainable pest control strategies against spider mites. In this study, the effects of six chemical insecticides viz. abamectin, bifenthrin, bifenazate, etoxazole, hexythiazox, and spinosad, and entomopathogenic fungus <em>Beauveria bassiana</em> and botanical neem oil were evaluated against adult and egg stages of <em>T.</em> <em>urticae</em> under laboratory conditions. Treated mites were kept in controlled conditions at 25 ± 1 ℃, 60–70% RH and a photoperiod of 16:8 h (L: D). The LC₅₀ values of all chemicals [for adults, abamectin (0.51 ml/L), bifenthrin (3.26 ml/L), bifenazate (3.82 ml/L), hexythiazox (3.27 ml/L) and spinosad (3.83 ml/L); for eggs, abamectin (0.56 ml/L), bifenthrin (3.48 ml/L), bifenazate (26.81 ml/L), hexythiazox (4.18 ml/L) and spinosad (18.28 ml/L)] suggest that they were effective against eggs and adult females of the <em>T. urticae</em>. Etoxazole (LC₅₀ = 3.99 ml/L) is recommended against egg stage. The neem oil was found to be moderately effective (for adult, LC₅₀ = 1.26%; for egg, LC₅₀ = 1.77%) against eggs and adult females of <em>T. urticae</em>. The <em>B. bassiana</em> was also found to be effective against eggs and adult females of <em>T. urticae</em>. Finally, it could be concluded that all chemicals used in this study are effective for the management of two spotted spider mite but the entomopathogenic fungus <em>B. bassiana</em> and botanical neem oil were promising alternatives for successful management of <em>T. urticae</em> in IPM programs. https://www.persianacarology.org/article_238635_c12155c141c692dd3a0db66518790090.pdf