Investigation on the effects of some microbial and botanical acaricides against two-spotted spider mite [Tetranychus urticae Koch (Acari: Tetranychidae)] under laboratory conditions

Thesis Type: Postgraduate

Institution Of The Thesis: Bursa Uludağ University, FEN BİLİMLERİ ENSTİTÜSÜ, BİTKİ KORUMA, Turkey

Approval Date: 2020

Thesis Language: Turkish

Student: Gizem Keskin

Supervisor: Nabi Alper Kumral


The effects of some botanical and microbial acaricides against two-spotted spider mites, Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) which is main pest of vegetables and fruits, were assesed during 2018-2019 in this study. Essential oil obtained from water distillation process of basil leaves [Ocimum basilicum L. (Lamiales: Lamiaceae)] and crude oil obtained from the cold-pressed process of chinaberry tree seeds [Melia azedarach L. (Sapindales: Meliaceae)] and a commercial neem oil product (Nimbecidine) [Azadirachta indica (A. Juss, 1830) (Sapindales: Meliaceae)] were used as botanical acaricides. Microbial product was a commercial formulation of Paecilomyces fumosoreus strain PFs-1. Based on acute toxic studies, the lethal concentrations of Nimbecidine, chinaberry and basil oils (LC50 and LC90) 0,79 and 1,83 mg/L; 4,04 and 6,94%; 4,85 and 10,32%, 72 h after treatmentusing a residual method on leaf disc. The lethal times (LT50 and LT90) of Nimbecidine (1 mg/L), chinaberry (6%) and the basil (8,4%) were 64 and 107 h, 41 and 73 h, 65 and 110 h, respectively. According to regression analysis, the increase in concentrations of botanical acaricides, the death response of T. urticae showed significant effect. The females had a strong aversion to bean leaf surfaces sprayed with the sublethal concentrations of Nimbecidine (0,125-0,75 mg/L), chinaberry (0,75-3%) and basil (0,71,4%) oils. Significant decreases were recorded in the number of eggs laid on bean leaves sprayed with the sublethal concentrations for Nimbecidine (0,03-0,5mg/L), chinaberry (0,75-3%) and the basil (1,4-5,6%) oils compared with unsprayed bean leaves. The recommended field (250x108 colonies/da) and different concentrations of Paecilomyces fumosoreus were applied to T.urticae. According to the acute toxic effects studies, the mortality of all doses was determined to be very low at 48th hour. The effects of highest dose was 57% at 48h, 96% at 96h.