The effect of strip-intercropping pepper and garlic on the control of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus urticae Koch, is an important pest of agricultural crops in Iran. In this study, intercropping pepper (P),Capsicum annuum L., with garlic (G), Allium sativum L., in the three patterns 3T:5G, 3T:8G and 3T:11G (row ratios) along with sole pepper crop were assessed on the densities of T. urticae,diversity of natural enemies and crop yield in an experimental field, based on a randomized complete block design during the two growing seasons 2017 and 2018. The densities of T. urticae eggs and mobile forms were lower in the three intercrops compared with sole pepper crop (p < /em> ≤ 0.05). The values of the Shannon diversity index (H´) and the Pielou’s evenness index (J´) for the composition of T. urticae predators were greater in the three intercrops compared with sole pepper crop. In the present study, Stethorus gilvifrons (Mulsant) and Orius niger (Wolff) were the main predators of T. urticae on pepper plants. The abundance of O. niger was higher in the three intercrops compared with sole pepper crop, but the populations of S. gilvifrons had not significant difference between intercrops and sole pepper crop (p < /em> ≤ 0.05). Moreover, the values of land equivalent ratio (LER) were greater than one in the three intercrops (LER ≥ 1.14) compared to sole crops. These results revealed that intercropping pepper with garlic could be an effective method in the integrated management of T. urticae in pepper fields.