The drumming of Isoperla pallida Aubert and Guadalgenus franzi (Aubert) (Plecoptera, Perlodidae), and review and evolutionary considerations of Southern Iberian Peninsula Perlodidae.

The drumming calls of two perlodid species from Southern Spain (Sierra Morena, Jaén) are analyzed and described. Nineteen calls from one male of Guadalgenus franzi were recorded, showing a simple call pattern composed of two beats with an average duration between them of 184.32 msec (range: 165-227). This is the simplest call pattern yet discovered in the Plecoptera. The female of this species also presented a simple call consisting of only one beat. The male of Isoperla pallida showed an ancestral call pattern, more simple than the other Iberian Isoperla species (I. grammatica, I. nevada or I. curtata, all of them with multiphasic drumming calls or I. bipartita with a notably different model consisting of rubbing). Calls from six different males (the female did not drum) consisted of an average of 65.94 beats (range: 25-83) with a duration average of 1462.69 msec (range: 548-1835), regularly repeated with intervals with a duration average of 22.27 msec (range: 17-30). With this study, the vibrational calls of all the Perlodid species from the Southern Iberian Peninsula, except Perlodes microcephalus and Besdolus bicolor, are known. Moreover, it presents the first record and description of the call of the monospecific genus Guadalgenus. An evolutionary approach to the vibrational communication diversification in the perlodids of the Southern Iberian Peninsula is presented, showing a complexity graduation from the more simple drumming calls (shown by Hemimelaena flaviventris and G. franzi) to the rubbing call of I. bipartita and intermediate drumming calls of other Isoperla species, consistent with the drumming evolution paradigm of Stewart (2001).