Bioacoustics of Neduba lucubrata

Distribution. Santa Lucia and Diablo Ranges in the South Coast Range, California. Habitat. Mixed woodland and chaparral. Taken from twigs in tangles, poison oak, and California sage ( Artemisia californica Less. ). Males call approximately 1 m above ground level in thick tangles. At dusk two males and one female emerged for nocturnal activity from a pack rat nest, suggesting that this structure served as a daytime shelter for an aggregation of individuals. These individuals retreated into the nest when disturbed. Seasonal occurrence. Adults from late July ( 22-VII-2015 , JA Cole and DB Weissman , LACM) through early September ( 8-IX-2002 , JA Cole , LACM). Stridulatory file. (n = 7) length 3.2–3.8 mm , 121–186 teeth, tooth density 45.9 ± 4.2 (38.4–50.0) teeth/mm. Song. (n = 31) Brief bouts separated by long intervals between bouts. PTR is 4.0 ± 0.5 s- 1. Males may add one PT to each successive bout, for example three successive bouts may consist of 3 PT, 4 PT, then 5 PT, and then the cycle recommences at 3 PT. PTF is 14.9 ± 0.8 kHz. Males may accompany stridulation with audible drumming, which is generated by the abdomen striking the substrate ( Weissman 2001 ; JAC pers. obs.). Drumming coincides with partial PT at the beginning of a bout ( Fig. 23 ). Drumming does not occur frequently and may not occur in all populations. Drumming was observed at the Monterey County localities of Arroyo Seco (one of two males, DBW , JAC , pers. obs.) and Bottcher’s Gap ( JAC , pers. obs.), but not at any San Benito County localities . Karyotype. (n = 8) Unique. 2n♁ = 24 ( 2m + 20t + XtYt). T83-37, S83-107, paratopotype. Recognition. With a single apical protibial spine, dark apical tegminal spots and prosternal spines, this species may be confused only with N. propsti , a larger species that does not occur on the California mainland. The female subgenital plate length and width are subequal, in contrast with the elongated subgenital plate of N. propsti . The song, which consists of short stridulation bouts accompanied by drumming, is unique.

Etymology. l. lucubrata burning the midnight oil, descriptive of male acoustic activity continuing throughout the night. Notes. This species shares morphological and genitalic characteristics with N. propsti as well as with the species of the Sierranus and Castanea Groups. Santa Lucia Range and Diablo Range populations are genetically distinct ( Figs. 3–5 ) but are separable neither morphologically nor bioacoustically. The chirping song structure combined with abdominal drumming makes N. lucubrata the most acoustically distinct species of Neduba . Selection for mate recognition may have driven the evolution of distinctive song phrasing in N. lucubrata , as within its distribution are found two sympatric nedubines: N. carinata and a small Aglaothorax species. Females may require silent periods of an appropriate intermediate length between bouts to recognize a conspecific male signal (Cole 2016): intermediate length gaps between PT bouts will contrast with the continuous PT production of sympatric N. carinata as well and the long periods of silence between pulse production in Aglaothorax .