Isoperla rougensis

Sandberg, John B. & Stewart, Kenneth W., 2006, Continued Studies Of Vibrational Communication (Drumming) Of North American Plecoptera, Illiesia 2 (1), pp. 1-14 : 6

Isoperla rougensis .

One hundred twenty-eight and 111 signals were obtained from one, 1-day old male and female, respectively, at room temperature and normal incandescent light near a window. The male and the female produced 2-way duets either with the female answer following the call (N=78) or with interspersed answer beats during the male’s 3 rd (N=1), 5 th (N=5) or 6 th (N=27) beat intervals. The male called with signals of 7 mode beats (6.9 ± 0.3); with intervals of 37.2 ± 3.2 ms ( Fig. 3 –B , Table 1 ). The male’s average individual intervals gradually increased from 31.6 ms (i1) to 39.5 (i5), the last interval decreased to 38.9 ms (N=117) ( Table 2). Mode and mean number of beats per female answer signal were 7 and 6.5 ± 1.7; mean beat interval was 40.8 ± 7.2 ms for sequenced and overlapped duets. The ♂ - ♀ exchange interval was 27.9 ± 27.5 ms. A split-channel view ( Fig. 3B ), revealed overlapped and interspersed female beats during the 5 th and 6 th call intervals.

Figures

Figs. 1–6. 1. Soliperla campanula drumming. Bar = 100-msec, total duration (TD)= 257-msec; 2. Isoperla muir drumming. (A) Male call, TD = 482-msec, (B) 2-way duet, TD = 960-msec. Bars = 500-msec.; 3. Isoperla rainera drumming. (A) Male call, TD = 1172-msec, (B) 2-way duet, female answer to computer playback of male call, TD = 2150-msec. Bars = 500-msec; 4. Isoperla rougensis drumming. (A) 2-way duet with female interspersed answer, (B) Split-channel view reveals previously hidden female first answer beats, TD = 574-msec. Bars = 500-msec; 5. Isoperla tilasqua drumming: 2-way duet with female interspersed answer, TD = 849-msec. Bar = 500 msec; 6. Pteronarcys scotti drumming: 2-way duet with female interspersed answer, TD = 4725-msec. Bar = 1000-msec.