Field spray abdominal gland secretions of rove beetles: Effects on the pest abundance and arthropod community

Alternative environmentally friendly methods for pest control are in high demand because of the environmental impacts of pesticides. Notably, predator-released kairomone is a natural compound released by natural enemies, which mediates non-consumptive effects between natural enemies and prey. However, this novel pest control agent is underutilized relative to pesticides and natural enemies. Additionally, the effects of spraying predator kairomone on the number and diversity of arthropods in fields and whether this method is environmental-friendly are poorly understood. In the present study, a predator kairomone, rove beetle (Paederus fuscipes Curtis) abdominal gland secretion (AGS), was sprayed in rice fields to investigate whether AGS can suppress pest populations or will affect the fields’ arthropod communities. After AGS spraying, the abundance of arthropods decreased throughout the first 12-d period, including arthropod pests such as hemipterans (small brown planthopper, Laodelphax striatellus (Fallén), brown planthopper, Nilaparvata lugens (Stål), white-backed planthopper, Sogatella furcifera (Horváth), and leafhoppers), and lepidopterans (rice leaf folder, Cnaphalocrocis medinalis Guenée). The abundance of arthropod predators was not affected, except for predatory spiders, which decreased, and rove beetles (P. fuscipes), which increased. In the terms of arthropod diversity, neither pests nor their natural enemies were changed by AGS application. This work highlights that predator kairomone can temporarily suppress pest populations in fields but has no adverse effects on arthropod diversity; thus, this approach is environmentally friendly and can be used in real-world applications. Broadly, present studies suggest that the application of predator kairomone may have synergistic or cumulative effects on pest suppression.