Insect attachment on waxy plant surfaces: the effect of pad contamination by different waxes

• Elena V. Gorb and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2024, 15, 385–395, doi:10.3762/bjnano.15.35

• experimentally supports the contamination hypothesis. Keywords: adhesion; Chrysolina fastuosa; Chrysomelidae; Coleoptera; epicuticular wax projections; tenent setae; traction force; Introduction It has been shown in numerous experimental studies that insects possessing hairy adhesive pads (i.e., specialized

• (3D) epicuticular wax projections, insects usually fail to attach to [4][5][6]. The reducing effect of such plant surfaces on insect adhesion has been shown for many plant and insect species using various experimental approaches, from direct behavioral observations and simple inversion [7] or incline

• plant wax had a primary effect on the force reduction. Contaminability of insect pads by waxes of different plant species was visualized in an additional experiment. Results and Discussion Waxy plant surfaces The plant surfaces studied are densely covered by different types of epicuticular wax

Biomimetics on the micro- and nanoscale – The 25th anniversary of the lotus effect

• Matthias Mail,
• Kerstin Koch,
• Thomas Speck,
• William M. Megill and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 850–856, doi:10.3762/bjnano.14.69

• epicuticular wax coverage on leaves of Deschampsia antarctica as a possible adaptation to severe environmental conditions”, used cryo-scanning electron microscopy to study surfaces of D. antarctica, one of the only two flowering plants native to Antarctica. The results show that the two-layered wax, which

Design of a biomimetic, small-scale artificial leaf surface for the study of environmental interactions

• Miriam Anna Huth,
• Axel Huth,
• Lukas Schreiber and
• Kerstin Koch

Beilstein J. Nanotechnol. 2022, 13, 944–957, doi:10.3762/bjnano.13.83

• in 20 mL chloroform. Five independent biological replicates were analyzed (n = 5). For the extraction of epicuticular wax from outdoor plants, leaf 2, 3, and 4 were pooled together for one replicate. Here the analysis of six independent biological replicates was performed (n = 6). Leaves were scanned

• substance classes, so that there were no notable differences in the relative wax composition and the corresponding wax morphology (Supporting Information File 1, Figure S4). Abiotic factors can have an influence on the amount of epicuticular wax. For example, previous studies have shown that higher

• increasing magnifications; (c) orange: cuticle, green: cell wall, blue: cytoplasm, (d) orange: epicuticular wax crystals, brown: cuticle. (1) Reduction of arthropod pest attachment, (2) complex functions of trichomes, for example, generation of air turbulences, (3) host-pathogen recognition/signaling for

Hierachical epicuticular wax coverage on leaves of Deschampsia antarctica as a possible adaptation to severe environmental conditions

• Elena V. Gorb,
• Iryna A. Kozeretska and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2022, 13, 807–816, doi:10.3762/bjnano.13.71

• outer glume were wax-free, both leaf sides had a prominent epicuticular wax coverage consisting of two superimposed layers: polygonal rodlets formed by fused irregular platelets (the lower wax layer) and membraneous platelets (the upper wax layer). Although the adaxial (inner) and abaxial (outer) leaf

• surfaces might contribute to the plant adaptation to severe environmental conditions in Antarctica due to an increase of its resistance against cold temperatures, icing, harmful UV radiation, and dehydration. The presence of the epicuticular wax on the abaxial leaf side and the ligule as well as the

• epicuticular wax coverage on the leaf surfaces in the adaptation of D. antarctica to the severe Antarctic environment. Additionally, the results obtained from this highly specialized plant species might be potentially interesting for biomimetics of technical surfaces or surface coatings exposed to similar

Polarity in cuticular ridge development and insect attachment on leaf surfaces of Schismatoglottis calyptrata (Araceae)

• Venkata A. Surapaneni,
• Tobias Aust,
• Thomas Speck and
• Marc Thielen

Beilstein J. Nanotechnol. 2021, 12, 1326–1338, doi:10.3762/bjnano.12.98

• epidermal cell wall are linked by a transition region that is rich in cellulose, hemicellulose, and pectin [1][2][3][4][5]. The outer peripheral layer of the cuticle may show various microscopic morphological structures such as cuticular ridges, epicuticular wax crystals, trichomes, and hairy structures [4

• hydrophobicity of the leaf surfaces [8][9]. On petals, they might act additionally as diffraction gratings producing structural colors to attract pollinators [10][11][12]. Ridges are relatively robust compared with other cuticular morphologies [8] such as epicuticular wax crystals. They may also provide

Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

• Miriam Anna Huth,
• Axel Huth and
• Kerstin Koch

Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70

• ]. As early as 1871, de Bary proposed the designation “crystal” for the wax structures [10]. This hypothesis was later verified by X-ray diffraction [11][12]. The most common crystalline structure of epicuticular wax crystals is the orthorhombic order [13]. Studies of growing plant waxes showed that wax

Bioinspired self-healing materials: lessons from nature

• Joseph C. Cremaldi and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2018, 9, 907–935, doi:10.3762/bjnano.9.85

• superhydrophobic functionality of the surface. In doing so, the rolling drops pick up or absorb particulates and dirt, cleaning the leaf. The superhydrophobic behavior is caused by a combination of hierarchical surface roughness at the nanometer and microscale combined with an epicuticular wax coating [32]. The

Kinetics of solvent supported tubule formation of Lotus (Nelumbo nucifera) wax on highly oriented pyrolytic graphite (HOPG) investigated by atomic force microscopy

• Sujit Kumar Dora,
• Kerstin Koch,
• Wilhelm Barthlott and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2018, 9, 468–481, doi:10.3762/bjnano.9.45

• ; crystallization; epicuticular wax; Lotus; Nelumbo nucifera; nonacosanol tubules; self-assembly; superhydrophobic; Introduction The plant cuticle, a cutin matrix embedded and covered by waxes provides a multitasking interface between plant and environment [1]. These waxes are either reside within the cutin layer

• (intracuticular wax) or deposited over the cutin surface (epicuticular wax) of primary plant organs. Being the first point of contact between plants and environment, the cuticle provides protection against water loss and external environmental stresses. Other important functions include control of transpiration

• seems rather probable that water plays an important role in the natural formation process of the epicuticular wax layer. This role may not only be that of an inert transport medium. Due to their capability of forming hydrogen-bridge bonds with functional groups of the wax molecules water molecules could

Surfactant-induced enhancement of droplet adhesion in superhydrophobic soybean (Glycine max L.) leaves

• Oliver Hagedorn,
• Ingo Fleute-Schlachter,
• Hans Georg Mainx,
• Viktoria Zeisler-Diehl and
• Kerstin Koch

Beilstein J. Nanotechnol. 2017, 8, 2345–2356, doi:10.3762/bjnano.8.234

• epicuticular wax showed that 1-triacontanol (C30H61OH) is the main wax component of the soybean leaf surfaces. A water contact angle (CA) of 162.4° (σ = 3.6°) and tilting angle (TA) of 20.9° (σ = 10.0°) were found. Adherence of pure water droplets on the superhydrophobic leaves is supported by the hydrophilic

• reduction of the epicuticular wax structures and a change from Cassie–Baxter wetting to an intermediate wetting regime with an increase of droplet adhesion. Keywords: droplet adhesion; epicuticular wax; Glycine max L; superhydrophobic; surfactants; Introduction The cuticle, as the outermost layer of

• tissues (shoots, leaves, fruits) of higher plants [10][11]. It is built up by a network of the cross-linked ester-like biopolymer, cutin, with integrated (intracuticular) and superimposed (epicuticular) waxes [12][13]. A large diversity of epicuticular wax chemistry and morphology has been described [14

Collembola cuticles and the three-phase line tension

• Håkon Gundersen,
• Hans Petter Leinaas and
• Christian Thaulow

Beilstein J. Nanotechnol. 2017, 8, 1714–1722, doi:10.3762/bjnano.8.172

• al demonstrated a lipid layer (epicuticular wax) covering all parts of the Collembola cuticle, using time-of-flight secondary ion mass spectrometry [30]. A lipophilic dye, such as Nile Red, will bind to any part of such a layer it came into contact with, thus staining the part of a surface wetted by

• summer conditions [6]. This change in wetting behavior is not accompanied by considerable structural changes in the cuticle. Gundersen et al. concluded that changes in the epicuticular wax layer was a possible explanation. Assuming θ0 = 120° in Equation 2 yields a predicted contact angle of ≈ 135

• °, below the contact angle observed in both summer- and winter-acclimated animals (Figure 5). The coverage of epicuticular wax was previously assumed to be either the top of the cuticular granules, leaving the areas between the granules exposed, or the entirety of the cuticle, recent studies conclude that

Innovations from the “ivory tower”: Wilhelm Barthlott and the paradigm shift in surface science

• Christoph Neinhuis

Beilstein J. Nanotechnol. 2017, 8, 394–402, doi:10.3762/bjnano.8.41

• )? Epicuticular wax tubules (lower right) shared by ranunculids were one argument to place Nelumbo (upper right) close to the latter systematic group. First demonstrator exhibiting the principle of self-cleaning derived from lotus leaves. Depending on new developments, or changes in perception the selection

When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs

• Niall Crawford,
• Thomas Endlein,
• Jonathan T. Pham,
• Mathis Riehle and
• W. Jon P. Barnes

Beilstein J. Nanotechnol. 2016, 7, 2116–2131, doi:10.3762/bjnano.7.201

• distributed over their surfaces. Indeed, cuticular folds have been demonstrated to be slippery for beetles [9][10], and stomata also contribute to a leaf’s roughness. Additionally, on some plants (e.g., the stems of Macaranga trees), one may find epicuticular wax crystals [11]. In Macaranga, the resulting

• ., Macaranga trees [12]) or attempt to capture them (e.g., pitcher plants [47]). In both cases, the surfaces will be slippery or otherwise non-adhesive. In many cases, the slipperiness is produced by surfaces covered by epicuticular wax crystals, which break off, contaminating the insect’s adhesive pads [48

Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

• Elena Gorb,
• Sandro Böhm,
• Nadine Jacky,
• Louis-Philippe Maier,
• Kirstin Dening,
• Sasha Pechook,
• Boaz Pokroy and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2014, 5, 1031–1041, doi:10.3762/bjnano.5.116

• roughness dropped in the order of surfaces C36–C40–C44–C50, it demonstrated a similar dependence on the chain length as did the morphometrical variables of crystals. Interestingly, the values of surface roughness parameters measured using AFM on the crystalline epicuticular wax in the pitcher of the

Impact of cell shape in hierarchically structured plant surfaces on the attachment of male Colorado potato beetles (Leptinotarsa decemlineata)

• Bettina Prüm,
• Robin Seidel,
• Holger Florian Bohn and
• Thomas Speck

Beilstein J. Nanotechnol. 2012, 3, 57–64, doi:10.3762/bjnano.3.7

• , leading to hierarchical surfaces if both levels are present. While it has been shown that epicuticular wax crystals and cuticular folds strongly reduce insect attachment, and that smooth papillate epidermal cells in petals improve the grip of pollinators, the impact of hierarchical surface structuring of

• papillate cell shape, covered either with flat films of wax, epicuticular wax crystals or with cuticular folds. On surfaces possessing either superimposed wax crystals or cuticular folds we found traction forces to be almost one order of magnitude lower than on surfaces covered only with flat films of wax

• or papillate cells enhancing attachment and both wax crystals or cuticular folds reducing attachment. However, the overall magnitude of traction force mainly depends on the presence or absence of superimposed microstructuring. Keywords: cuticular folds; epicuticular wax crystals; insect–plant

The effect of surface anisotropy in the slippery zone of Nepenthes alata pitchers on beetle attachment

• Elena V. Gorb and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2011, 2, 302–310, doi:10.3762/bjnano.2.35

• microscopic epicuticular wax crystals on top of both cell types (Figure 1A and Figure 1D). Numerous lunate cells (477.3 ± 46.02 per mm2, N = 3) are regularly distributed singly over the surface, whereas wax crystals form a continuous coverage. Lunate cells have a special crescent shape with their ends pointed

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and

• lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves. Keywords: epicuticular wax; leaf surface; Lotus effect; papillae; water repellency; Introduction Since the introduction of the ‘Lotus concept’ in 1992 [1][2], the

• been known for a long time that plant surfaces covered with epicuticular wax crystals are water repellent, and that this feature is enhanced when the epidermis has additional structures such as papillae or hairs [5][6]. Neinhuis and Barthlott (1997) [7] presented an overview of more than 200 species