Responses of all tested beetles to strong IR radiation.

<p>Responses are given on the left Y-axis (blue bars) as latency until the threshold criterion for a change in flight direction had been reached (mean of the angle had to differ from the mean at stimulus onset by the double SD at stimulus onset). On the right Y-axis (red bars) responses are given as angle of flight direction in the 7<sup>th</sup> second after stimulus onset. On the X-axis the 14 tested beetles are listed. Significant differences between changes in angle caused by irradiation of the left and right body side exist in beetles 8, 9 and 14 (asterisks, data of beetles 11 and 14 tested with the Mann-Whitney U test, data for all others tested with the t-test, significance level for both tests was p ≤ 0.05; in beetle 14 only 5 stimulus applications per body side were made). In beetle 11 the threshold criterion was not reached when irradiation was carried out from left. (<b>A</b>) IR radiation given from the left. (<b>B</b>) IR radiation given from the right.</p>