Aversive reactions of two invertebrate predators to European red–black insects

• Published in: Ethology 2023-01, Vol.129 (1), p.24-32
• Main Authors: Segovia, Julio M. G., Pekár, Stano
• Format: Article
• Language: English
• Subjects: Aversion; Coccinellidae; Crickets; defenses; heteroptera; Hypotheses; Insects; Invertebrates; mimetic complex; Mimicry; Palatability; Predators; Prey; Protected species; Small mammals; Species; Spiders; Sympatric populations
• ISSN: 0179-1613; 1439-0310
• DOI: 10.1111/eth.13341

Prey species gain protection by imitating signals of unpalatable models in defensive mimicry. Mimics have been traditionally classified as Batesian (palatable mimic resembling an unpalatable model) or Müllerian (unpalatable mimic resembling a similarly unpalatable model). However, recent studies suggest that rather than discrete categories, the phenomenon of mimicry can be better understood as a continuum. The level of unpalatability of defended prey is a key factor in determining the type of mimetic relationship. Herein, we used insects (ladybugs and true bugs) from a putative European “red–black” mimetic complex as experimental models of defended species and crickets as a control prey. We offered the prey to two species of sympatric invertebrate predators (praying mantis and spider) and video recorded the interactions. We tested three alternative hypotheses, namely (i) the three red–black species tested are similarly defended against both predators; (ii) some red–black species are better defended than others against both predator species, and (iii) the effectiveness of the red–black species defenses is predator dependent. Both predators attacked all prey types with a similar frequency. But while all three red–black species similarly elicited aversive behaviors in spiders, the mantises' aversive reactions varied depending on the prey species. Our results provide support to the third hypothesis, suggesting that the same prey species can fall into different parts of the spectrum of palatability–unpalatability depending on the type of predator. Predatory interactions with two invertebrate predators (spiders left panel; mantises right panel) and four prey types suggest that the levels of unpalatability of the red–black prey are predator dependent (firebug—Pyrrhocoris apterus, ladybug (Ha)—Harmonia axyridis, ladybug (Cs)—Coccinella septempunctata, shield bug—Graphosoma lineatum). We used crickets (Gryllus assimilis) as a control prey.