Multitrait aposematic signal in Batesian mimicry

Abstract

Batesian mimics can parasitize Müllerian mimicry rings mimicking the warning color signal. The evolutionary success of Batesian mimics can increase adding complexity to the signal by behavioral and locomotor mimicry. We investigated three fundamental morphological and locomotor traits in a Neotropical mimicry ring based on Ithomiini butterflies and parasitized by Polythoridae damselflies: wing color, wing shape, and flight style. The study species have wings with a subapical white patch, considered the aposematic signal, and a more apical black patch. The main predators are VS-birds, visually more sensitive to violet than to ultraviolet wavelengths (UVS-birds). The white patches, compared to the black patches, were closer in the bird color space, with higher overlap for VS-birds than for UVS-birds. Using a discriminability index for bird vision, the white patches were more similar between the mimics and the model than the black patches. The wing shape of the mimics was closer to the model in the morphospace, compared to other outgroup damselflies. The wing-beat frequency was similar among mimics and the model, and different from another outgroup damselfly. Multitrait aposematic signals involving morphology and locomotion may favor the evolution of mimicry rings and the success of Batesian mimics by improving signal effectiveness toward predators.

Fireflies thwart bat attack with multisensory warnings

“…Wingbeat rates have been implicated as a component of warning signals in systems with visually guided predators. Convergence in wingbeat rates within aposematic mimicry groups occurs in heliconiine butterflies ( 39 , 40 ), as well as in damselfly mimics of ithomiine butterflies ( 41 ). Considering the prevalence of chemically protected flying insects ( 8 ), the roles of flight-based warning signals, transduced by vision, echolocation, or passive listening are fertile grounds for future research, particularly as it applies to multisensory signaling.…”

Frequency dependence shapes the adaptive landscape of imperfect Batesian mimicry

“…High light intensity and Endler's daylight or forest shade irradiance spectra [40] were used. Comparisons were made for white reflectance spectra only, because white is considered an important mimetic feature in other butterfly mimicry systems [41,42], and visual inspection of the reflectance spectra did not reveal any differences between the other wing colours, orange and brown (electronic supplementary material, figures S3-S4).…”

Complex dynamics underlie the evolution of imperfect wing pattern convergence in butterflies

“…Measurement of the blue-and long wavelength-absorbing rhodopsins of butterflies in the Limenitis lineage within Adelpha indicates that adult eyes contain photopigments with peak absorbances of ß430 nm and 515-530 nm, respectively (Frentiu et al 2007;Frentiu et al 2015), which (together with the ultraviolet opsin) are in good locations to potentially permit the detection of differences between A. iphiclus and A. serpa whites (Figs. To test this possibility, future experiments using an achromatic butterfly control to test for brightness alone (to determine whether color, instead of brightness, is a more effective stimulus) should be performed, especially because white coloration has been noted as an important mimetic feature in other butterfly mimicry systems (Beccaloni 1997;Outomuro et al 2016). Additionally, based on our discriminability modeling results, it is likely avian predators are capable of detecting these spectral differences between the wing whites, and therefore able to recognize and avoid A. iphiclus.…”

“…However, under three of the four scenarios used in our avian vision model, the natural wing white comparisons done between physical butterfly specimens fall just under the discriminability threshold of 1 just noticeable difference, whereas three of the four comparisons for the artificial butterfly whites lie just above the threshold (Table 1), suggesting that the potential for Batesian mimicry to occur might be higher in nature than in the context of our experiment. To test this possibility, future experiments using an achromatic butterfly control to test for brightness alone (to determine whether color, instead of brightness, is a more effective stimulus) should be performed, especially because white coloration has been noted as an important mimetic feature in other butterfly mimicry systems (Beccaloni 1997;Outomuro et al 2016).…”