Kunming Institute of Zoology, Chinese Academy of Sciences
Abstract
The yellow granules in the gastral cuticle of the Oriental hornet Vespa
orientalis (Hymenoptera, Vespinae) are located in yellow stripes. In
the present study, we focus on the micromorphology and formation of the
yellow granules from their inception to their spread in the regions
which are destined to acquire a yellow color. The cuticle was observed
with several methods of electron microscopy. The results showed that
the yellow granules comprise a layer which is 40-45 µm thick,
within the total cuticular thickness of 40−45 µm. In the
mentioned regions one can see, from above, many apertures of about 0.5
µm in diameter which extends into a peripheral photoreceptor cell.
In each yellow granule, one discerns a myoid envelope inside which
there are 9 fibrils arranged in a circle. Yellow granules maturation
process involves infiltration of canals that give rise to the incipient
ball-shaped primary granules which increase in number (as a result of
continues budding off the walls of a canal) as the cuticle matures and
transform into secondary barrel shaped granules, becoming elongated and
then splitting into shorter barrels that fill up the entire area.
Preliminary examinations have suggested liver-like function activity
within the layer of yellow granules
