Are ciliary hair cells and photoreceptors components of a gravitic system of the hornet Vespa orientalis?
Social wasps, including the sub-family Vespinae, are social insects that build combs beneath the ground which are directed towards the gravitic pull of the earth, and this in dim light or complete darkness. On the inner side of the frons plate in social wasps there is a gravity sensing apparatus composed of static and dynamic nerve fibers, some of which connect between the frons plate and the brain. It is highly probable that the interaction between the fibers and the various structures in the head is responsible for the proprioceptive ability of hornets, including gravity detection. Ishay et al called the apparatus involved, the "Ishay Organ", and also reported the presence of (stereo) cilia on the inner side of the frons plate. The frons plate which bears the gravity organs functions as a photovoltaic system. Additionally there are throughout the cuticle, at intervals of several micrometers apart, distinct pores which are the outlets of peripheral photoreceptors. In the past various investigators have studied the ciliar structures of different insects mainly by TEM, but we have now studied the hair cells in hornets by FE-SEM, to obtain a complete 3-dimensional image of the various hair cell structures involved.
Jongebloed
W L
WL
Lab. for Cell Biology & Electron Microscopy, Groningen University.
Rosenzweig
E
E
Kalicharan
D
D
Ishay
J S
JS
D000818:Animals; D018466:Gravity Sensing / Q000502:physiology*; D006198:Hair Cells, Auditory / Q000502:physiology* / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology*; D014863:Wasps