Mandible strike kinematics of the trap‐jaw ant genus Anochetus Mayr (Hymenoptera: Formicidae)

Abstract

High‐speed power‐amplification mechanisms are common throughout the animal kingdom. In ants, power‐amplified trap‐jaw mandibles have evolved independently at least four times, including once in the subfamily Ponerinae which contains the sister genera Odontomachus and Anochetus. In Odontomachus, mandible strikes have been relatively well described and can occur in <0.15 ms and reach speeds of over 60 m s−1. In contrast, the kinematics of mandible strikes have not been examined in Anochetus, whose species are smaller and morphologically distinct from Odontomachus. In this study, we describe the mandible strike kinematics of four species of Anochetus representative of the morphological, phylogenetic, and size diversity present within the genus. We also compare their strikes to two representative species of Odontomachus. We found that two species, Anochetus targionii and Anochetus paripungens, have mandible strikes that overall closely resemble those found in Odontomachus, reaching a mean maximum rotational velocity and acceleration of around 3.7 × 104 rad s−1 and 8.5 × 108 rad s−2, respectively. This performance is consistent with predictions based on body size scaling relationships described for Odontomachus. In contrast, Anochetus horridus and Anochetus emarginatus have slower strikes relative to the other species of Anochetus and Odontomachus, reaching mean maximum rotational velocity and acceleration of around 1.3 × 104 rad s−1 and 2 × 108 rad s−2, respectively. This variation in strike performance among species of Anochetus likely reflects differences in evolutionary history, physiology, and natural history among species.

Thermal robustness of biomechanical processes

“…Other movements hypothesized to be spring actuated have not been studied in the context of temperature, but may yet be revealed as thermally robust. For example, recoiling elastic structures power prey capture and processing in numerous aquatic invertebrates and vertebrates (Longo et al, 2018;Patek et al, 2004;Van Wassenbergh et al, 2008) as well as terrestrial animals (Gibson et al, 2018;Han et al, 2019;Kaji et al, 2018;Patek et al, 2006;Wood, 2020;Wood et al, 2016). Moreover, they enable jumping in several insect species (Burrows, 2003;Sutton and Burrows, 2018) and sound production in some insects (Bennet-Clark and Daws, 1999;Davranoglou et al, 2019).…”

Latch-based control of energy output in spring actuated systems

“…By using LaMSA mechanisms, small and lightweight organisms achieve accelerations and velocities far beyond what their muscles and actuators can accomplish alone. Trap-jaw ants (mandible strike: 64 m s −1 at an average acceleration of the order of 10 6 m s −2 ) [7][8][9][10][11][12][13], mantis shrimp ( predatory strike: up to 31 m s −1 at an average acceleration of the order of 10 4 m s −2 ) [14][15][16][17][18], froghoppers ( jump: 4.7 m s −1 at an average acceleration of the order of 10 3 m s −2 ) [19,20], and even soft-bodied gall midges ( jump: 0.88 m s −1 at an average acceleration on the order of 880 m s −2 ) [21] are just a few examples. Furthermore, LaMSA mechanisms are used in a variety of organisms for diverse applications ranging from prey capture and predator evasion, to jumping locomotion.…”

Corrieopone nouragues gen. nov., sp. nov., a new Ponerinae from French Guiana (Hymenoptera, Formicidae)

“…Since 2001, 17 Ant Course editions have trained nearly 500 students from 59 countries, included more than 60 international instructors, and offered opportunities to explore the biological diversity in different parts of the globe, from Australia to Southeast Asia, to East Africa, and to North, Central, and South America ( www.antcourse.org ). Specimens collected in past editions enhanced our understanding of several aspects of ant biology, such as functional morphology (e.g., Peeters et al 2017 ; Larabee et al 2017 , 2018 ; Gibson et al 2018 ), ecology ( Kronauer 2004 ), reproductive biology ( Peeters 2017 ), and natural history (LaPolla et al 2004; Lattke and Delsinne 2016 ). The course also created opportunities for remarkable discoveries.…”