The two-spotted spider mite Tetranychus urticae prefers soybean plants with higher nutritional quality

Microorganisms and arthropods may interact indirectly through plant-mediated mechanisms. Among these microorganisms, phosphate-solubilizing bacteria, commonly used as bioinoculants, have been widely employed to improve phosphorus fertilization efficiency. However, the effects of these inoculations on plant defense mechanisms and herbivory remain inconsistent, varying according to plant species and nutritional status. We aim was to evaluate whether the application of different bioinoculants to soybean plants influences host preference, development, oviposition, and population growth of the two-spotted spider mite, Tetranychus urticae . Soybean plants were subjected to the following treatments: (i) BRM 119 ( Bacillus megaterium ) + BRM 2084 ( Bacillus subtilis ); (ii) BRM 119 + BRM 2084 +  Bradyrhizobium sp.; (iii) Azospirillum sp.; (iv) Azospirillum sp. + BRM 119 + BRM 2084; (v) fertilization with 0.375 g NPK (control); and (vi) fertilization with 0.750 g NPK.. Adult female T. urticae exhibited a greater preference for bioinoculant-treated plants than for control plants. In addition, inoculated plants supported higher population growth of the mite. Inoculation with B. subtilis reduced developmental time and increased oviposition. However, the total number of individuals was not affected by the treatments. These findings suggest that the application of bioinoculants may increase the attractiveness of soybean plants and enhance the biological performance of T. urticae , possibly as a result of improved host plant nutritional quality. Therefore, the adoption of these bioinoculants should be accompanied by appropriate monitoring and management strategies for the two-spotted spider mite in soybean crops.