Data from: To quiver or to shiver: increased melanisation benefits thermoregulation, but reduces warning signal efficacy in the wood tiger moth

• Main Authors: Hegna, Jonathan R., Nokelainen, Ossi, Mappes, Johanna, Hegna, R. H.
• Format: Dataset
• Language: unknown
• Published: 2013
• Subjects: aposematism; Parasemia plantaginis; Shiver; North Finland
• Online Access: https://zenodo.org/record/4935688; https://doi.org/10.5061/dryad.82c67

Melanin production is often considered costly, yet beneficial for thermoregulation. Studies of variation in melanization and the opposing selective forces that underlie its variability contribute greatly to understanding natural selection. We investigated whether melanization benefits are traded off with predation risk to promote observed local and geographical variation in the warning signal of adult male wood tiger moths (Parasemia plantaginis). Warning signal variation is predicted to reduce survival in aposematic species. However, in P. plantaginis, male hindwings are either yellow or white in Europe, and show continuous variation in melanized markings that cover 20 to 90 per cent of the hindwing. We found that the amount of melanization increased from 40 to 59 per cent between Estonia (58° N) and north Finland (67° N), suggesting melanization carries thermoregulatory benefits. Our thermal measurements showed that more melanic individuals warmed up more quickly on average than less melanic individuals, which probably benefits flight in cold temperatures. With extensive field experiments in central Finland and the Alpine region, we found that more melanic individuals suffered increased predation. Together, our data suggest that warning signal efficiency is constrained by thermoregulatory benefits. Differences in relative costs and benefits of melanin probably help to maintain the geographical warning signal differences. Melanin cline datasetData on the hindwing melanin across Estonia and up through Finland.Thermal dataData used in the thermoregulation study showing the temperature change after being under a radiant heat source.PredationThe number of attacks on artificial moth models on each transect.