Control mechanism of calling behaviour in Lymantria dispar: an electrophysiological investigation on the role of the terminal abdominal ganglion

Using a modified "grease electrode", we recorded extracellular spike activity from either member of each of the six pairs of peripheral nerves of the terminal abdominal ganglion in the female gypsy moth. Our results show that the three most caudally located nerve pairs (nerve pairs IV, V and VI) carry most of the spike activity related to the ovipositor movements associated with calling. The spike trains from nerve pair VI presented a temporal pattern which correlated most closely to the extension and retraction of the ovipositor during calling. Transection of the ventral nerve cord anterior to the terminal ganglion stopped neither the spike activity nor the calling behaviour, but some slight changes in both the spike frequency patterns and the duration of ovipositor extension and retraction were detected. We conclude that the terminal abdominal ganglion exhibits a considerable degree of autonomy in its control of the calling behaviour in the female gypsy moth. © 1988