cac¹/Df(1)RC29 females show convulsions and locomotor defects when exposed to 37^oC. The convulsion phenotype is characterised by the flies turning upside-down onto their backs or onto their sides for a few seconds. In addition the flies sometimes curl their abdomens severely (either when on their backs or walking), and occasionally the flies spin around. The courtship song parameters interpulse interval, cycles per pulse and amplitude of sound are higher in cac¹ males than in wild-type males. The difference in courtship song interpulse interval between cac¹ and wild-type males shows a significant negative correlation with temperature.

Aberrant intervals between song pulses. Some pulses, however, are quasi-normal in their cycle numbers; these, as well as many of the polycyclic pulses, have essentially normal intra-pulse frequencies; other pulses exhibit anomalous modulations and these show multiple peaks in the intra-pulse spectra, unlike wild type.

Song mutant. Vision normal (behaviorally and physiologically).

Males court abnormally with poor mating success and aberrant courtship song, which includes pulses of tone that are polycyclic, rather than monocyclic or tricyclic, within wild-type pulses and have increased amplitude. Mating success of wingless mutant males is still worse than that of wingless wild-type males, which is correlated with genetic separability of song abnormalities from deficit in mating performance. Female courtship appears to be unaffected by cac; but general locomotor activity of males or females is subnormal. cac is recessive for generally abnormal behavior and for courtship song defects in tra flies (Kulkarni, Hall and Schilcher).