Breaking the cipher: ant eavesdropping on the variational trail pheromone of its termite prey

Abstract

Predators may eavesdrop on their prey using innate signals of varying nature. In regards to social prey, most of the prey signals are derived from social communication and may therefore be highly complex. The most efficient predators select signals that provide the highest benefits. Here, we showed the use of eusocial prey signals by the termite-raiding ant Odontoponera transversa . O. transversa selected the trail pheromone of termites as kairomone in several species of fungus-growing termites (Termitidae: Macrotermitinae: Odontotermes yunnanensis , Macrotermes yunnanensis , Ancistrotermes dimorphus ). The most commonly predated termite, O. yunnanensis, was able to regulate the trail pheromone component ratios during its foraging activity. The ratio of the two trail pheromone compounds was correlated with the number of termites in the foraging party. (3 Z )-Dodec-3-en-1-ol (DOE) was the dominant trail pheromone component in the initial foraging stages when fewer termites were present. Once a trail was established, (3 Z,6Z )-dodeca-3,6-dien-1-ol (DDE) became the major recruitment component in the trail pheromone and enabled mass recruitment of nest-mates to the food source. Although the ants could perceive both components, they revealed stronger behavioural responses to the recruitment component, DDE, than to the common major component, DOE. In other words, the ants use the trail pheromone information as an indication of suitable prey abundance, and regulate their behavioural responses based on the changing trail pheromone component. The eavesdropping behaviour in ants therefore leads to an arms race between predator and prey where the species specific production of trail pheromones in termites is targeted by predatory ant species.

Death recognition by undertaker bees

“…Ratios of signal compounds encode behavioural specific information in social insects (11, 13). Although SPME is not accurate in detecting the actual ratios of CHC compounds, basically, the ratio of compounds in the volatiles is quite different from the ratio of compounds in the whole body extract under the same HS-SPME extraction method (Fig.…”

“…The dynamics of emission of a signal are related to the signal’s behavioural function in a social context. For a recruitment signal, release should be positively correlated with the number of individuals involved (11, 12). In contrast, a decrease in inhibitory signals can result in the release of an inhibited behaviour.…”

Ant‐termite interactions: an important but under‐explored ecological linkage

“…A subterranean Dorylus ant species is an effective predator of termites, performing regular raids on termite colonies in Africa (Bodot, ; Abe & Darlington, ). Similarly, Odontoponera transversa follows the pheromones produced by termites to track and hunt them (Wen et al ., ). A particular adaptation occurs in Neoponera marginata : worker ants sting termites during raids to paralyse them, and the immobilised termites are then stored in the ant nest as a living food reserve (Leal & Oliveira, ).…”

Investment in chemical signalling glands facilitates the evolution of sociality in lizards

“…up to months for the snake Crotalus viridis [69]). Scent-marks effectively transmit the same information both passively and continuously, thereby increasing the probability of detection and accurate processing by conspecifics [19,23] (but also heterospecifics [70,71]) and help stabilize social systems [72][73][74].…”