Continued Studies Of Vibrational Communication (Drumming) Of North American Plecoptera Author Sandberg, John B. & Kenneth W. Stewart & E-mail: jbs 001 @ unt. edu Author Stewart, Kenneth W. Department of Biological Sciences, University of North Texas, Denton, TX 76203 & E-mail: stewart @ unt. edu stewart@unt.edu text Illiesia 2006 2006-03-08 2 1 1 14 journal article http://doi.org/10.5281/zenodo.4758579 b39773d2-f5ab-46f1-a8e5-dc7f64a9fca6 1854-0392 4758579 Isoperla sobria . This species from a new location was analyzed individually during 2001 and 2004. A total of 99 and 20 signals were obtained from two 3-11 day old males and females, respectively. Recording occurred at room temperature and normal incandescent light in 2001 and 23–24°C and 84 FTC in 2004. In both years, males and females produced 2-way sequenced signals with either the female answer signal following the call (N=12), or with the beginning answer beats interspersed within the males 2 nd (N=1), 3 rd (N=3), 4 th (N=3) and 5 th (N=1) interval. In 2001, the male called with 4 mode beats (3.7 ±0.8); with intervals of 159.1 ± 7.2 ms and in 2004, with 6 mode beats (5.2 ± 1.0); with intervals of 151.1 ± 5.8 ms ( Fig 11 , Table 3 ). The 2001 average individual intervals gradually decreased from 162.4 ms (i1) to 156.1 ms (i2), then increased to 163.1 ms (i4) ( Table 4 ). The 2004 average individual intervals gradually decreased from 152.4 ms (i1) to 147.7 ms (i2), then increased to 154.6 ms (i6) ( Table 4 ). The 2001 mode and mean number of beats per female answer signal were 1 and 1.1 ± 0.2; beat interval was 62.9 ms (N=1). The 2001 ♂ - ♀ exchange interval was 99.8 ± 5.6 ms for sequenced and overlapped duets. The 2004 female answer signals contained only a single interspersed beat and the ♂ - ♀ exchange interval was 112.8 ± 4.0 ms. These results agree well within reasonable expected variation, with those of Sandberg and Stewart (2003) and do not suggest a new dialect.