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Naturwissenschaften

, Volume 96, Issue 7, pp 781–787 | Cite as

Waterproof and translucent wings at the same time: problems and solutions in butterflies

  • Pablo Perez GoodwynEmail author
  • Yasunori Maezono
  • Naoe Hosoda
  • Kenji Fujisaki
Original Paper

Abstract

Although the colour of butterflies attracts the most attention, the waterproofing properties of their wings are also extremely interesting. Most butterfly wings are considered “super-hydrophobic” because the contact angle (CA) with a water drop exceeds 150°. Usually, butterfly wings are covered with strongly overlapping scales; however, in the case of transparent or translucent wings, scale cover is reduced; thus, the hydrophobicity could be affected. Here, we present a comparative analysis of wing hydrophobicity and its dependence on morphology for two species with translucent wings Parantica sita (Nymphalidae) and Parnassius glacialis (Papilionidae). These species have very different life histories: P. sita lives for up to 6 months as an adult and migrates over long distance, whereas P. glacialis lives for less than 1 month and does not migrate. We measured the water CA and analysed wing morphology with scanning electron microscopy and atomic force microscopy. P. sita has super-hydrophobic wing surfaces, with CA > 160°, whereas P. glacialis did not (CA = 100–135°). Specialised scales were found on the translucent portions of P. sita wings. These scales were ovoid and much thinner than common scales, erect at about 30°, and leaving up to 80% of the wing surface uncovered. The underlying bare wing surface had a remarkable pattern of ridges and knobs. P. glacialis also had over 80% of the wing surface uncovered, but the scales were either setae-like or spade-like. The bare surface of the wing had an irregular wavy smooth pattern. We suggest a mode of action that allows this super-hydrophobic effect with an incompletely covered wing surface. The scales bend, but do not collapse, under the pressure of a water droplet, and the elastic recovery of the structure at the borders of the droplet allows a high apparent CA. Thus, P. sita can be translucent without losing its waterproof properties. This characteristic is likely necessary for the long life and migration of this species. This is the first study of some of the effects on the hydrophobicity of translucency through scales’ cover reduction in butterfly wings and on the morphology associated with improved waterproofing.

Keywords

Biomaterials Functional morphology Hydrophobic Scales Water contact angle 

Notes

Acknowledgements

We thank Prof. Ko Okumura (Ochanomizu Women’s University, Tokyo, Japan) and Prof. Shinya Yoshioka (Osaka University, Graduate School of Frontier Sciences) for insightful discussions. We are also grateful to Hiroki Takamatsu (Kyoto University, Graduate School of Agriculture, Laboratory of Insect Ecology) for supplying some butterfly specimens. We thank the comments and suggestions of the referees and the editors, which considerably improved an early version of this manuscript.

Supplementary material

114_2009_531_MOESM1_ESM.pdf (24 kb)
Fig. S1 Reflectance spectra (in percentage) of each species: Parnassius P. glacialis; Parant. transl. translucent part of P. sita; Parant. black black part of P. sita; Parant. brown brown part of P. sita. X-axis wavelength in nanometre (PDF 23 kb)
114_2009_531_MOESM2_ESM.pdf (8 kb)
Fig. S2 Model showing the action of specialised scales of P. sita. Under the weight of a drop, the scales bend and the water can contact the bare surface of the wing. Along the borders of the drop, the scales rise because of their elasticity, thus, producing a much higher CA (PDF 7 kb)
Movie 1

Water drop (diameter approx. 2.5 mm) sled sideward with a micromanipulator over the wing of P. sita (MOV 7579 kb)

Movie 2

Water drop (diameter approx. 2.5 mm) sled sideward with a micromanipulator over the wing of P. sita, pressed up and down (MOV 8102 kb)

References

  1. Auckland JN, Debinski DM, Clark WR (2004) Survival, movement, and resource use of the butterfly Parnassius clodius. Ecol Entomol 29:139–149CrossRefGoogle Scholar
  2. Bálint Z, Vértesy Z, Biró LP (2005) Micro-structures and nanostructures of high Andean Penaincisalia lycaenid butterfly scales (Lepidoptera: Lycaenidae): descriptions and interpretations. J Nat Hist 39:2935–2952CrossRefGoogle Scholar
  3. Bernhard CG, Miller WH (1962) A corneal nipple pattern in insect compound eyes. Acta Physiol Scand 56:385–386PubMedCrossRefGoogle Scholar
  4. Berthier S (2007) Iridiscences. The physical colors of insects. Springer, New YorkGoogle Scholar
  5. Brower LP (1988) Avian predation on the monarch butterfly and its implications for mimicry theory. Am Nat 131:4–6CrossRefGoogle Scholar
  6. Bush JWM, Hu DL, Prakash M (2008) The integument of water-walking arthropods: Form and function. In: Casas J, Simpson SJ (eds) Advances in insect physiology. insect mechanics and control. Academic Press, New York, pp 117–192Google Scholar
  7. Davis AK, Cope N, Smith A, Solensky MJ (2007) Wing color predicts future mating success in male monarch butterflies. Ann Entomol Soc Am 100:339–344CrossRefGoogle Scholar
  8. Extrand CW (2004) Criteria for ultralyophobic surfaces. Langmuir 20:5013–5018PubMedCrossRefGoogle Scholar
  9. Ghiradella H (1989) Structure and development of iridescent butterfly scales: lattices and laminae. J Morphol 202:59–88CrossRefGoogle Scholar
  10. Ghiradella H (1994) Structure of butterfly scales: patterning in an insect cuticle. Microsc Res Tech 27:429–438PubMedCrossRefGoogle Scholar
  11. He B, Patankar NA, Lee J (2003) Multiple equilibrium droplet shapes and design criterion for rough hydrophobic surfaces. Langmuir 19:4999–5003CrossRefGoogle Scholar
  12. Hernández-Chavarría F, Hernández A, Sittenfeld A (2004) The “windows”, scales, and bristles of the tropical moth Rothschildia lebeau (Lepidoptera: Saturniidae). Rev Biol Trop 52:919–926PubMedGoogle Scholar
  13. Kawabe S (1994) Inference of life pattern on "Parantica sita niphonica Moore"[sic.] in Okayama prefecture (in Japanese). Bull Okayama Univ Sci A 30:141–151Google Scholar
  14. Konvička M, Kuras T (1999) Population structure, behaviour and selection of oviposition sites of an endangered butterfly, Parnassius mnemosyne, in Litovelske Pomoravil. Czech Republic. J Ins Cons 3:211–223CrossRefGoogle Scholar
  15. Miyatake Y, Fukuda H, Kanazawa I (2003) Asagimadara. The travelling butterfly (In Japanese). Mushi sha, TokyoGoogle Scholar
  16. Perez Goodwyn PJ (2008) Anti-wetting surfaces in Heteroptera (Insecta): hairy solutions to any problem. In: Gorb SN (ed) Functional surfaces in biology: little structures with big effects: vol 1. Springer, DordrechtGoogle Scholar
  17. Prum RO, Quinn T, Torres RH (2006) Anatomically diverse butterfly scales all produce structural colours by coherent scattering. J Exp Biol 209:748–765PubMedCrossRefGoogle Scholar
  18. Sato E (2006) Asagimadara: The mystery of the sea-crossing butterfly (In Japanese). Yama to Keikoku sha, TokyoGoogle Scholar
  19. Stalder AF, Kulik G, Sage D, Barbieri L, Hoffmann P (2006) A snake-based approach to accurate determination of both contact points and contact angles. Coll Surf A 286:92–103CrossRefGoogle Scholar
  20. Uesugi K (1996) Adaptive significance of Batesian mimicry in the swallowtail butterfly, Papilio polytes (Insecta, Papilionidae): associative learning in a predator. Ethol 102:762–775Google Scholar
  21. Vértesy Z, Bálint Z, Kertész K, Vigneron JP, Lousse V, Biro LP (2006) Wing scale micro-structures and nanostructures in butterflies - natural photonic crystals. J Microsc 224:108–110PubMedCrossRefGoogle Scholar
  22. Vukusic P, Sambles JR, Lawrence CR (2004) Structurally assisted blackness in butterfly scales. Biol Lett 271:237–239Google Scholar
  23. Wagner T, Neinhuis C, Barthlott W (1996) Wettability and contaminability of insect wings as a function of their surface sculptures. Acta Zool 77:213–225CrossRefGoogle Scholar
  24. Watson GS, Myhra S, Cribb BW, Watson JA (2008) Putative functions and functional efficiency of ordered cuticular nanoarrays on insect wings. Biophys J 94:3352–3360PubMedCrossRefGoogle Scholar
  25. Yoshida A, Motoyama M, Kosaku A, Miyamoto K (1997) Antireflective nanoprotuberance array in the transparent wing of a hawkmoth, Cephonodes hylas. Zool Sci 14:737–741CrossRefGoogle Scholar
  26. Yoshioka S, Kinoshita S (2006) Structural or pigmentary? Origin of the distinctive white stripe on the blue wing of a Morpho butterfly. Proc Roy Soc B 273:129–134CrossRefGoogle Scholar
  27. Zheng Y, Gao X, Jiang L (2007) Directional adhesion of superhydrophobic butterfly wings. Soft Matt 3:178–182CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Pablo Perez Goodwyn
    • 1
    Email author
  • Yasunori Maezono
    • 1
  • Naoe Hosoda
    • 2
  • Kenji Fujisaki
    • 1
  1. 1.Laboratory of Insect Ecology, Graduate School of AgricultureKyoto UniversityKyotoJapan
  2. 2.Interconnect Design GroupNational Institute for Materials ScienceTsukubaJapan

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