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Microcrystals coating the wing membranes of a living insect (Psocoptera: Psyllipsocidae) from a Brazilian cave.

Lienhard C, Ferreira RL, Gnos E, Hollier J, Eggenberger U, Piuz A - Sci Rep (2012)

Bottom Line: They did not exhibit any signs of reduced vitality in the field and their morphology is completely normal.Guano probably played a role in its formation; the presence of iron may be a consequence of the excretion of iron by the common vampire bat.This enigmatic phenomenon lacks obvious biological significance but may inspire bionic applications.

View Article: PubMed Central - PubMed

Affiliation: Natural History Museum of the City of Geneva, CP 6434, CH-1211 Geneva 6, Switzerland. charleslienhard@bluewin.ch

ABSTRACT
Two specimens of Psyllipsocus yucatan with black wings were found with normal individuals of this species on guano piles produced by the common vampire bat Desmodus rotundus. These specimens have both pairs of wings dorsally and ventrally covered by a black crystalline layer. They did not exhibit any signs of reduced vitality in the field and their morphology is completely normal. This ultrathin (1.5 µm) crystalline layer, naturally deposited on a biological membrane, is documented by photographs, SEM micrographs, energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). The crystalline deposit contains iron, carbon and oxygen, but the mineral species could not be identified. Guano probably played a role in its formation; the presence of iron may be a consequence of the excretion of iron by the common vampire bat. This enigmatic phenomenon lacks obvious biological significance but may inspire bionic applications. Nothing similar has ever been observed in terrestrial arthropods.

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Psyllipsocus yucatan, black female, SEM micrographs.(a) Right fore wing (untreated), general view of ventral surface (micrograph A. Wetzel, Bern). (b) Left fore wing (gold coated), ventral surface, completely smooth membrane visible at left due to local detachment of crystalline layer.
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f6: Psyllipsocus yucatan, black female, SEM micrographs.(a) Right fore wing (untreated), general view of ventral surface (micrograph A. Wetzel, Bern). (b) Left fore wing (gold coated), ventral surface, completely smooth membrane visible at left due to local detachment of crystalline layer.

Mentions: Figure 6a shows the general view of the right fore wing (ventral surface) of the female, air-dried but untreated, before using this wing for crystallographic analysis. The deposit layer on the membrane is almost intact but the cuticular microstructures of the margin and veins are well visible due to their incomplete covering by this layer (for details see Figures 6b and 7a). Some SEM micrographs of the gold coated left wings of the same specimen are presented in Figures 6 and 7. They show that the layer covering wing membranes consists of a compact deposit of numerous slightly elongate, suboval microcrystals (width somewhat less than 1 µm, length about 2 µm). The layer of parallel oriented crystals tightly adheres to the dorsal and ventral surface of the wing membrane (Figure 7c). Due to mechanical bending of the wings for SEM preparation this crystalline layer is locally detached from the wing membrane (Figures 6b, 7b). The wing membrane is smooth and appears completely unstructured in SEM (Figure 6b, at left along vein), it is about 0.25 µm thick (Figure 7c). The crystalline layer on the dorsal surface of the wing is about 1.5 µm thick, that on the ventral surface slightly thinner (Figure 7b, c). The parts of the wings bearing cuticular sculpture, as the veins (Figure 6b) and the margin (Figure 7a) are bare or only incompletely covered by microcrystals.


Microcrystals coating the wing membranes of a living insect (Psocoptera: Psyllipsocidae) from a Brazilian cave.

Lienhard C, Ferreira RL, Gnos E, Hollier J, Eggenberger U, Piuz A - Sci Rep (2012)

Psyllipsocus yucatan, black female, SEM micrographs.(a) Right fore wing (untreated), general view of ventral surface (micrograph A. Wetzel, Bern). (b) Left fore wing (gold coated), ventral surface, completely smooth membrane visible at left due to local detachment of crystalline layer.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3351784&req=5

f6: Psyllipsocus yucatan, black female, SEM micrographs.(a) Right fore wing (untreated), general view of ventral surface (micrograph A. Wetzel, Bern). (b) Left fore wing (gold coated), ventral surface, completely smooth membrane visible at left due to local detachment of crystalline layer.
Mentions: Figure 6a shows the general view of the right fore wing (ventral surface) of the female, air-dried but untreated, before using this wing for crystallographic analysis. The deposit layer on the membrane is almost intact but the cuticular microstructures of the margin and veins are well visible due to their incomplete covering by this layer (for details see Figures 6b and 7a). Some SEM micrographs of the gold coated left wings of the same specimen are presented in Figures 6 and 7. They show that the layer covering wing membranes consists of a compact deposit of numerous slightly elongate, suboval microcrystals (width somewhat less than 1 µm, length about 2 µm). The layer of parallel oriented crystals tightly adheres to the dorsal and ventral surface of the wing membrane (Figure 7c). Due to mechanical bending of the wings for SEM preparation this crystalline layer is locally detached from the wing membrane (Figures 6b, 7b). The wing membrane is smooth and appears completely unstructured in SEM (Figure 6b, at left along vein), it is about 0.25 µm thick (Figure 7c). The crystalline layer on the dorsal surface of the wing is about 1.5 µm thick, that on the ventral surface slightly thinner (Figure 7b, c). The parts of the wings bearing cuticular sculpture, as the veins (Figure 6b) and the margin (Figure 7a) are bare or only incompletely covered by microcrystals.

Bottom Line: They did not exhibit any signs of reduced vitality in the field and their morphology is completely normal.Guano probably played a role in its formation; the presence of iron may be a consequence of the excretion of iron by the common vampire bat.This enigmatic phenomenon lacks obvious biological significance but may inspire bionic applications.

View Article: PubMed Central - PubMed

Affiliation: Natural History Museum of the City of Geneva, CP 6434, CH-1211 Geneva 6, Switzerland. charleslienhard@bluewin.ch

ABSTRACT
Two specimens of Psyllipsocus yucatan with black wings were found with normal individuals of this species on guano piles produced by the common vampire bat Desmodus rotundus. These specimens have both pairs of wings dorsally and ventrally covered by a black crystalline layer. They did not exhibit any signs of reduced vitality in the field and their morphology is completely normal. This ultrathin (1.5 µm) crystalline layer, naturally deposited on a biological membrane, is documented by photographs, SEM micrographs, energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). The crystalline deposit contains iron, carbon and oxygen, but the mineral species could not be identified. Guano probably played a role in its formation; the presence of iron may be a consequence of the excretion of iron by the common vampire bat. This enigmatic phenomenon lacks obvious biological significance but may inspire bionic applications. Nothing similar has ever been observed in terrestrial arthropods.

Show MeSH
Related in: MedlinePlus