Navigation and thermophotovoltaic activity by hornets at different light conditions: the influence of UVB blockers.
The aim of the present investigation was two-fold: a) to observe the homing of the Oriental hornet, Vespa orientalis (Hymenoptera, Vespinae) from different distances; and b) to study the photothermoelectric activity of hornet cuticle obtained from the subjects of goal (a) and kept frozen for a number of days prior to its testing. In both the above mentioned phases of the investigation, an attempt was made to assess how the covering of the hornets' cuticle with Ultra Violet B (UVB) blockers affects their activity as compared to the control. Flying hornets were observed to return to the nest from distances of up to 7 km, once they had learned the way back. However, covering of the cuticle with UVB blockers increases the percentage of 'non-returners' to nearly 100%. Covering the cuticle completely or partly with a number of UVB blockers (except for Sisley) proves lethal for the hornets within 24 hours. A statistical model on homing is proposed of the effect of range, of covering with UVB blockers and covering ocelli with Tippex. In the wing of the hornet there is increase in the electric current with rise in the temperature and decrease in the current upon drop of the temperature, but light has no effect on this alar (wing) current. Contrariwise, the body cuticle of the hornet responds to both temperature and illumination in terms of its electric current. Coating of the cuticle with UVB blockers causes in the wing (under all conditions of illumination) and in the cuticle (only in the dark) a moderation in the amplitude of the photothermoelectric current.
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Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat-Aviv, Israel.
Litinetsky
L
L
Sverdlov
A
A
Rosenzweig
E
E
Ishay
J S
JS
D000818:Animals; D001522:Behavior, Animal; D004594:Electrophysiology; D006702:Homing Behavior / Q000502:physiology*; D008027:Light; D015233:Models, Statistical; D013473:Sunscreening Agents / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays; D014863:Wasps; D014921:Wings, Animal / Q000502:physiology
D013473:Sunscreening Agents