The invasive Thrips parvispinus spends its prepupal and pupal stages in the soil and the other stages on plant leaves. Its biological control can thus be achieved by releasing a combination of above- and below-ground predators. Some soil mites have been observed climbing plants, creating the possibility of their use both above and below- ground. However, their application in biocontrol remains poorly explored. We tested the effectiveness of the belowground predatory mite Rhabdocarpais consanguineus, alone and in combination with the predatory mite Amblyseius swirskii in controlling T. parvispinus on sweet pepper plants in cages in a greenhouse. In a first experiment, 10 adult female mites of A. swirskii and 20 R. consanguineus were released onto plants and into the soil, respectively, over two consecutive weeks. During the experiment, the mites were fed twice per week, with A. swirskii being fed Typhapollen on the plant leaves and R. consanguineus receiving Carpoglyphus lactis in the soil. After 14 and 21 days, three male and three female adult thrips were introduced onto the plants. Starting one week after the final release, the numbers of adult and second-instar thrips, adult predatory mites, total leaves, and damaged leaves were recorded once per week for nine weeks. We found that R. consanguineus significantly reduced the density of T. parvispinus; however, the level of control was not sufficient to prevent damage of some plants. Amblyseius swirskii, both alone and in combination with R. consanguineus, effectively controlled T. parvispinus. The densities of A. swirskii were lower when R. consanguineus were present than in their absence, either due to competition for the thrips prey or to intraguild predation. In a second experiment, we further investigated this interaction between the two predators. Five larvae, five protonymphs, and five deutonymphs of A. swirskii plus pollen were introduced onto small plants, either with or without 20 deutonymphs of R. consanguineus that were released on the soil without food. The remaining predators were counted after 48 hours. We found that the deutonymphs of R. consanguineus climbed from the soil onto the plants, where they fed on the larvae of A. swirskii. Despite the occurrence of this intraguild predation, the results of the first experiment show that A. swirskii can effectively control T. parvispinus, both alone and in combination with R. consanguineus. The added release of R. consanguineus to plants with A. swirskiidid not improve control.