A joint research group led by Assistant Professor Ryoya Tanaka and Professor Azusa Kamikouchi of the Graduate School of Science, Nagoya University, Assistant Professor Yuki Mitaka and Professor Daigo Takemoto of the Graduate School of Bioagricultural Sciences at Nagoya University, Researcher Mitsuhiko Sato of the Kazusa DNA Research Institute, and Lecturer Yoshinori Suzuki of the Graduate School of Pharmaceutical Sciences at Nagoya City University, has announced their discovery that a parasitic species of ant crickets which live in ant nests have escape strategies suited to the unique environment in the nest. The discovery was made by examining the escape behaviors of the crickets in response to ants. The results were published in the international journal Communications Biology on December 31.
Provided by Assistant Professor Ryoya Tanaka of Nagoya University and Lecturer Yoshinori Suzuki of Nagoya City University (Credit: Issey Takahashi)
Various organisms live inside ant nests, and these are called myrmecophiles (ant guests). Most myrmecophiles exploit ants' hydrocarbon-based communication strategies to dupe ants into believing "they are ants," and this is considered to be an effective chemical strategy to avoid attacks from ants. Meanwhile, some myrmecophiles are attacked when they are detected by ants, and escape behavior has been shown to be important for avoiding attacks; however, the underlying mechanism has remained unclear.
In the present study, the research group focused on a species of ant crickets devoid of adequate chemical strategies (Myrmecophilus tetramorii) and examined their escape behaviors in response to ants. The results showed that the ant crickets have two escape strategies: a strategy to get behind ants through relatively slow circular movement and the other to use high-speed linear movement. They classified the strategy of getting behind ants by following a circular-shaped trajectory at a relatively slow speed as "dodging" and the strategy of getting away from ants in a short time through high-speed linear movement as "distancing" and examined how the ant crickets switch between these two strategies.
Examinations of the interindividual distances between the cricket and the ant when the cricket initiated an escape behavior indicated that the crickets chose the "dodging" strategy when they were relatively far from ants and the "distancing" strategy when they close to them. The ant crickets appeared to switch the two different strategies depending on the risk of being attacked. Furthermore, the researchers observed the escape behavior in response to two species of ants that are not hosts of Myrmecophilus tetramorii and found that "dodging" may be a host-selective escape strategy. Simulations also revealed that "dodging" contributes to efficient foraging while avoiding ants in a limited space such as ant nests.
Tanaka said, "'Escaping' is a basic animal instinct, but I realized that there are various hidden strategies when we observe them closely. Many more unexpected, unique behavioral patterns may remain to be discovered, particularly in species with parasitic relationships, such as those studied here. Moving forward, I would like to keep the focus on the unique behaviors of insects and pursue research to elucidate the genetic and neural circuit mechanisms underlying these unique behaviors."
Journal Information
Publication: Communications Biology
Title: Switching escape strategies in the parasitic ant cricket Myrmecophilus tetramorii
DOI: 10.1038/s42003-024-07368-y
This article has been translated by JST with permission from The Science News Ltd. (https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.