Entomopathogenic fungi and their biological control of Tetranychus urticae: Two-spotted spider mites

The two-spotted spider mite (TSSM) Tetranychus urticae, is regarded as one of the most dangerous pests responsible for great losses in most of agricultural crops. It is a persistent pest in Saudi Arabia, especially in greenhouses where T. urticae is primarily controlled by chemical pesticides. The main problem for the two-spotted spider mites is its high resistance to pesticides and high fertility rate. In the long term, chemical pesticides cause health problems and economic losses, so it was necessary to search for a safe alternative method for human health and the environment. One of these alternative methods was the selection of plant varieties resistant to the TSSM, in addition to biological control that includes mites or predatory insects and entomopathogenic fungi. The growth, reproduction, and life-table parameters of T. urticae were examined in a laboratory setting with a 16L:8D photoperiod at 28 +/- 1 degrees C and 65 +/- 5% RH, in the presence of three major members of Family: Solanaceae tomato, eggplant, and pepper. Pepper was shown to be less conducive to T. urticae growth and reproduction compared to eggplant and tomato. Tetranychus urticae proceeded through all five stages of its life cycle (egg, larva, protonymph, deutonymph, and adult) on tested solanaceous plants, and these plants significantly influenced its growth, reproduction, and Life-table parameters. Additionally, entomopathogenic fungi have been used against insects that have proven highly effective in controlling and reducing the density of two-spotted spider mites. Eight fungi were isolated from 80 insect and mite samples collected from several Saudi Arabia regions. Analysis of the 18S rRNA sequences revealed that the fungal strains identified as Beauveria bassiana, Fusarium sp. F. equiseti, F. oxysporium, Scopulariopsis brevicaulis1, S. brevicaulis2, Aspergillus sclerotiorum, and Penicillium citrinum. The ability of isolated fungi to secrete enzymes degrading the two-spotted spider mite cuticle, namely lipase, protease, and chitinase, were studied. (c) 2023 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).