Insect aquaplaning: Nepenthes pitcher plants capture prey with the peristome, a fully wettable water-lubricated anisotropic surface

Proceedings of the National Academy of Sciences of the United States of America - Tập 101 Số 39 - Trang 14138-14143 - 2004
Holger F. Bohn1, Walter Federle1
1Zoologie II, Biozentrum, Am Hubland, 97074 Würzburg, Germany

Tóm tắt

Pitcher plants of the genus Nepenthes have highly specialized leaves adapted to attract, capture, retain, and digest arthropod prey. Several mechanisms have been proposed for the capture of insects, ranging from slippery epicuticular wax crystals to downward-pointing lunate cells and alkaloid secretions that anesthetize insects. Here we report that perhaps the most important capture mechanism has thus far remained overlooked. It is based on special surface properties of the pitcher rim (peristome) and insect “aquaplaning.” The peristome is characterized by a regular microstructure with radial ridges of smooth overlapping epidermal cells, which form a series of steps toward the pitcher inside. This surface is completely wettable by nectar secreted at the inner margin of the peristome and by rain water, so that homogenous liquid films cover the surface under humid weather conditions. Only when wet, the peristome surface is slippery for insects, so that most ant visitors become trapped. By measuring friction forces of weaver ants ( Oecophylla smaragdina ) on the peristome surface of Nepenthes bicalcarata , we demonstrate that the two factors preventing insect attachment to the peristome, i.e., water lubrication and anisotropic surface topography, are effective against different attachment structures of the insect tarsus. Peristome water films disrupt attachment only for the soft adhesive pads but not for the claws, whereas surface topography leads to anisotropic friction only for the claws but not for the adhesive pads. Experiments on Nepenthes alata show that the trapping mechanism of the peristome is also essential in Nepenthes species with waxy inner pitcher walls.

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Tài liệu tham khảo

Darwin C. (1875) Insectivorous Plants (Appleton London).

Lloyd F. E. (1942) The Carnivorous Plants (Ronald Press New York).

Knoll, F. (1914) Jahrb. Wiss. Bot. 54, 448–497.

10.1002/j.1537-2197.1977.tb15726.x

Juniper B. E. Robins R. J. & Joel D. M. (1989) The Carnivorous Plants (Academic London).

10.2307/2261474

10.1006/anbo.1999.0857

10.2307/2389076

10.1007/s00425-003-1075-7

10.1016/j.asd.2003.11.005

Gorb, E. V. (2004) Comp. Biochem. Physiol. A 137, S82–S83.

Hepburn, J. S. (1918) Proc. Am. Philos. Soc. 57, 112–129.

10.1093/oxfordjournals.jbchem.a129956

10.1007/BF00390820

10.1046/j.1469-8137.2002.00530.x

10.1007/s004420050390

10.1086/375422

10.1016/S0367-2530(17)30030-0

10.1017/S0266467400009160

Clarke C. & Wong K. M. (1997) Nepenthes of Borneo (Natural History Publications Kota Kinabalu Malaysia).

10.2307/2656921

10.1111/j.1096-3642.1856.tb00113.x

Juniper, B. E. & Burras, J. K. (1962) New Sci. 13, 75–77.

10.1073/pnas.97.12.6568

10.1242/jeb.203.3.505

10.1242/jeb.205.16.2479

10.1242/jeb.00716

10.1021/la010503y

10.1103/PhysRevLett.80.3296

Juniper B. E. & Jeffree C. E. (1983) Plant Surfaces (Edward Arnold London).

10.1002/jsfa.2740200214

10.1016/S0927-7757(02)00061-4

Wolf A. V. Brown M. G. & Prentiss P. G. (1984) in CRC Handbook of Chemistry and Physics ed. Weast R. C. (CRC Boca Raton FL) pp. D223–D272.

10.1111/j.1095-8312.1988.tb00465.x

Schuitemaker, J. P. & Staercke, A. (1933) Overdr. Natuurhist. Maandbl. 22, 29–31.

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Proceedings of the National Academy of Sciences of the United States of America

Tập 101 Số 39

14138-14143

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