Eyespots deflect predator attack increasing fitness and promoting the evolution of phenotypic plasticity.
Some eyespots are thought to deflect attack away from the vulnerable body, yet there is limited empirical evidence for this function and its adaptive advantage. Here, we demonstrate the conspicuous ventral hindwing eyespots found on Bicyclus anynana butterflies protect against invertebrate predators, specifically praying mantids. Wet season (WS) butterflies with larger, brighter eyespots were easier for mantids to detect, but more difficult to capture compared to dry season (DS) butterflies with small, dull eyespots. Mantids attacked the wing eyespots of WS butterflies more frequently resulting in greater butterfly survival and reproductive success. With a reciprocal eyespot transplant, we demonstrated the fitness benefits of eyespots were independent of butterfly behaviour. Regardless of whether the butterfly was WS or DS, large marginal eyespots pasted on the hindwings increased butterfly survival and successful oviposition during predation encounters. In previous studies, DS B. anynana experienced delayed detection by vertebrate predators, but both forms suffered low survival once detected. Our results suggest predator abundance, identity and phenology may all be important selective forces for B. anynana. Thus, reciprocal selection between invertebrate and vertebrate predators across seasons may contribute to the evolution of the B. anynana polyphenism.
Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA Department of Integrative Biology, Oregon State University, Corvallis, OR, USA klprudic@gmail.com.
Kathleen L
KL
Prudic
Department of Biology, Butler University, Indianapolis, IN, USA.
Andrew M
AM
Stoehr
Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.
Bethany R
BR
Wasik
Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA Department of Biological Sciences, National University of Singapore, Singapore NUS-Yale College, Singapore.
Antónia
http://orcid.org/0000-0001-9696-459X
A
Monteiro
D000818:Animals; D005075:Biological Evolution; D002080:Butterflies / Q000235:genetics / Q000502:physiology*; D005260:Female; D056084:Genetic Fitness; D007313:Insecta / Q000502:physiology; D008136:Longevity; D008297:Male; D010641:Phenotype; D010858:Pigmentation; D011235:Predatory Behavior; D012098:Reproduction; D012621:Seasons; D012641:Selection, Genetic; D014921:Wings, Animal / Q000502:physiology
adaptive coloration; visual signalling; wing patterns