THE LOCI OF CONTACT CHEMORECEPTORS INVOLVED IN FEEDING REACTIONS IN CERTAIN LEPIDOPTERA

¹ Department of Zoology and Entomology, The Pennsylvania State University, University Park; and The Mount Desert Island Biological Laboratory, Salisbury Cove, Maine

1. The loci of contact chemoreceptors, stimulation of which by sucrose solutions elicits proboscis extension, were determined for the butterflies: Cercyonis pegala and Lethe eurydice of the Satyridae, and Speyeria cybele and Limenitis arthemis of the Nymphalidae; and the diurnal moths: Ctenucha virginica and Scepsis fulvicollis of the Amatidae.

2. Local contact and excision methods were used. All have the receptors on the terminal part of the proboscis and on all the functional tarsi. The palpi probably do not bear the receptors, and in the butterflies the antennae likewise. In Ctenucha removal of the first two pairs of legs and in Scepsis removal of all the legs resulted in feeding reactions on stimulation of the antennae with sucrose solutions.

3. These results emphasize the need for careful control and specification of testing conditions and for cautious interpretation of negative results in experiments such as these.