Functional roles of ants in a temperate grassland

Anuran juveniles avoid preying on aggressive ant species

“…Japanese pavement ant T. tsushimae (body size, 2.5 mm) belonging to Myrmicinae, have a stinger suitable for secretion of trailing pheromone (Attygalle & David Morgan, 1984), but less functional in aggression. Garden ant L. japonicus (body size, 2.5–3.5 mm) belonging to Formicinae, can spray formic acid for defense when attacked by predators (Ohwada & Yamawo, 2021). In summary, B. chinensis and L. japonicus are relatively aggressive preys presumed to be high threat to anurans, whereas T. tsushimae is less dangerous as a prey.…”

“…Due to their eusociality, workers and soldiers are generally highly aggressive towards other animals, in order to defend their colony or to hunt the prey animals (Trompeter & Langkilde, 2011). For defense and hunting, many ants possess venomous stingers (Nelder et al, 2006) formic acid (Ohwada & Yamawo, 2021) or other chemical substances (Wilson & Regnier Jr, 1971), or well‐developed mandibles, hardened exoskeleton, spiny projections, or bristles on the dorsum of the body (Ito et al, 2016). Given that ants are highly abundant but potentially risky prey, their predators are expected to determine whether they prey on ants or not, according to the balance of benefits and risks of focal ants.…”

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Predators have evolved a variety of foraging behavior which will be determined by the balance between prey capture success and cost associated with predation. The costs include the energetic cost of foraging behavior, and the damages associated with the defensive traits of prey such as chemical substances (Ohwada & Yamawo, 2021;Wilson & Regnier Jr, 1971), physical guarding (stingers or spines) (Ito et al, 2016;Nelder et al, 2006), and counterattack (Trompeter & Langkilde, 2011). The optimality theory predicts that these costs are important determinants of prey preference (Davies et al, 2012).Additionally, prey preference can be innate or acquired after learning.

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