Temperature-dependent electrical resistivity of the hornet cuticle: Changes induced by colchicine and purine in the diet

Various cuticular areas of the Oriental hornet (Vespa orientalis) were measured for their electrical resistivity within the range of 3–40°C. It was found that: (1) the electrical resistivity is temperature dependent; (2) there are no significant differences in this respect between hornets collected in different regions; (3) there are no differences in the electrical resisitivity between the yellow and brown areas of the cuticle in control hornets; (4) there are however, significant changes in resistance between the yellow and brown strips of hornets fed on purine; (5) hornets fed on colchicine reach a minimum resistance at a higher temperature than do the control hornets; and (6) hornets fed on purine reach a minimum resistance at a lower temperature. It is suggested that the cuticular changes in resistivity at different temperatures reflect the hornets' mechanism of detecting and adjusting to changes in the ambient temperature.