Plant preference of Nesidiocoris tenuis (Hemiptera: Miridae) between tomato and a banker plant, Cleome hassleriana

The zoophytophagous mirid Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an important biological control agent that primarily acts against small insect pests of tomato (Solanum lycopersicum L., Solanales: Solanaceae). In Japan, biological control programs in vegetable greenhouses are primarily implemented using N. tenuis and cleome (Cleome hassleriana Chod., Brassicales: Cleomaceae), which is a suitable banker plant for maintaining this mirid. However, the preference of N. tenuis for crop or banker plant remains unclear. Here, we assayed the plant preference of N. tenuis between tomato and cleome using three colonies—individuals reproduced on Crassula ovata (Mill.) Druce (Saxifragales: Crassulaceae), tomato, and cleome. Moreover, we evaluated the effect of temporary (24 h) plant experience on the preference of N. tenuis. The plant preference was assayed by a dual-choice test using potted plants. The results showed that individuals reproduced on C. ovata showed equal preference for tomato and cleome, suggesting that N. tenuis has no innate preference for either of these plants. In contrast, individuals reproduced on tomato or cleome had a strong preference for the plant species on which they were grown. Furthermore, individuals who were temporarily exposed to a plant were more likely to prefer that plant. Our findings demonstrate that the preference of N. tenuis between tomato and cleome changes reversibly through learning, indicating that plant preference may be artificially manipulated. This study can help develop effective release strategies for N. tenuis, leading to improved banker plant systems for biological control.