Aversive Learning in the Praying Mantis (Tenodera aridifolia), a Sit and Wait Predator

Abstract

Animals learn to associate sensory cues with the palatability of food in order to avoid bitterness in food (a common sign of toxicity). Associations are important for active foraging predators to avoid unpalatable prey and to invest energy in searching for palatable prey only. However, it has been suggested that sit-and-wait predators might rely on the opportunity that palatable prey approach them by chance: the most efficient strategy could be to catch every available prey and then decide whether to ingest them or not. In the present study, we investigated avoidance learning in a sit-and-wait predator, the praying mantis (Tenodera aridifolia). To examine the effects of conspicuousness and novelty of prey on avoidance learning, we used three different prey species: mealworms (novel prey), honeybees (novel prey with conspicuous signals) and crickets (familiar prey). We sequentially presented the prey species in pairs and made one of them artificially bitter. In the absence of bitterness, the mantises consumed bees and crickets more frequently than mealworms. When the prey were made bitter, the mantises still continued to attack bitter crickets as expected. However, they reduced their attacks on bitter mealworms more than on bitter bees. This contrasts with the fact that conspicuous signals (e.g. coloration in bees) facilitate avoidance learning in active foraging predators. Surprisingly, we found that the bitter bees were totally rejected after an attack whereas bitter mealworms were partially eaten (~35%). Our results highlight the fact that the mantises might maintain a selection pressure on bees, and perhaps on aposematic species in general.Electronic supplementary materialThe online version of this article (10.1007/s10905-018-9665-1) contains supplementary material, which is available to authorized users.

The fishing mantid: predation on fish as a new adaptive strategy for praying mantids (Insecta: Mantodea)

“…This scenario, from a more speculative perspective, suggests the possibility that the insect learned from the experience where and what to hunt. Mantids are known to use aversive learning to avoid toxic prey (Carle et al 2018), a first basic learning ability shared by many predators. This case, however, suggests a further step to a more articulated cognitive process, including the ability to learn not only from a single stimulus but from different environmental clues and experiences, for elaborate new hunting strategies.…”

The Evolutionary Ecology of Flash Displays and Other Transiently Visible Anti-predation Signals

“…Therefore we can rule out the possibility that some form of specific coevolutionary relationship between these two species may have influenced our results. Previous studies have found that mantids are capable of learning to avoid warningly coloured defended prey (Carle et al, 2018). Our finding that naïve mantids were wary of large caterpillars with eyespots at the outset, indicates that praying mantids have largely an innate rather than learned tendency to be cautious of large potential prey with eye-like stimuli.…”

Methods for independently manipulating palatability and color in small insect prey

“…While previous learning studies have used DB-treated prey [42,54,61] and diet-manipulated milkweed bugs [25,69] as aversive stimuli, here we scaled down these methods for use with smaller, understudied arthropod predators and thoroughly investigated the merits (and potential drawbacks) for each method. Our data therefore provide practical guidance for using these techniques effectively in future manipulative experiments that examine learning, foraging, and aposematism.…”

“…While quinine has long been used as a bittering agent in taste aversion studies with many animals [57][58][59], we chose to use DB here because quinine has been shown to be ineffective with at least some jumping spider species, which will readily eat quinine-laced prey [60]. In invertebrate predators, there are two main aversive conditioning studies (to our knowledge) that used DB, both of which manipulated the palatability of prey offered to mantids by injecting and coating prey with DB solution [61,62]. Despite its widespread effectiveness in studies with avian predators, and more recent use with mantid predators, little is known about the effectiveness of DB when applied solely to the surface of much smaller prey and offered to smaller invertebrate predators.…”