The Biology and Management of the White-footed Ant Technomyrmex brunneus in Japan

Abstract

White-footed ants of the genus Technomyrmex (Hymenoptera: Formicidae) originated from Asia but have invaded several subtropical regions of the globe and have become significant pests in recent years. Invasive populations of T. brunneus in Japan have ecological characteristics typical of other invasive ants, such as polygyny, unicoloniality, pre-adaptation to disturbed habitats, and herbivorous but flexible feeding habits. This species shows extreme polygyny and high reproductivity, because its colonies include numerous intercastes (worker-like queens). Therefore, population densities reach high levels, leading them to become a serious nuisance as household pests. Additionally, T. brunneus possesses other characteristics that make its control difficult, such as arboreality, absence of trophallaxis, low insecticide susceptibility, and bait preference biased to liquids. Recent studies have revealed that hydrogel baits, which are liquid baits sustained by superabsorbent polymers, are suitable for controlling this species. Here we review the pest status, ecology, and control of T. brunneus and indicate future research directions to stop the damage it causes.