Bioacoustics of Neduba propsti

Distribution. Restricted to Santa Catalina Island, Los Angeles County, California , USA . Probably found throughout the island in suitable habitat. Habitat. Dense chaparral vegetation, often on steep hillsides and in canyon bottoms. Individuals prefer to sit on the inner twigs of tangles. Also, in gardens on non-native vegetation. One individual taken from ornamental eucalyptus (JAC, pers. obs.). Seasonal occurrence. Adult records from mid-June ( 14-VI-1985 , S Bennett , CAS ) through July ( 28-VII-1981 DB Weissman , CAS ) . Stridulatory file. (n = 5) length 3.2–3.9 mm , 94–111 teeth, tooth density 30.4 ± 2.1 (28.2–33.0) teeth/mm. Song. (n = 10) Continuous 200 ms MPTL at a brisk PTR of 4.4 ± 0.4 s- 1. PT consist of the least amount of pulses (toothstrikes) of any species (~20). PTF approaches the ultrasonic at 18.5 ± 3.5 kHz. A captive male drummed at irregular intervals while stridulating ( Fig. 20 ); the drums were audible and induced considerable substrate vibration in the cage. Karyotype. (n = 4) Unique. 2n♁ = 24 ( 4m + 18t + XmYt). T85-12, S85-70, topotype. Recognition. Shares the following morphological characters with N. lucubrata : a single apical spine on the fore tibiae, prosternal spines, and tegmina darkened apically. The stridulatory file has a lower tooth density (28–33 teeth/ mm) than any other species except those of the Castanea Group. Male genitalia of N. propsti are similar to those of N. castanea and N. macneilli , but the arms of the titillators of N. propsti have a shaft that is straight and not swollen at a distance of 1/6 from the base as in the latter two species ( Plate 10 ). The song is unique in having short MPTL produced continually at a rapid PTR. Females have the longest subgenital plate of any species, approximately 1.5 times longer than wide. This is the only nedubine on Santa Catalina Island ( Figs. 8 , 19 ) with the most southerly distribution of any Neduba . Notes. N. propsti is an early branching lineage ( Figs. 3–5 ) that has apparently been isolated on Santa Catalina Island for a long time. The island has never been connected to mainland California ( Legg et al. 2004 ) being the product of tectonic uplift. Males may be wary and cease calling at the slightest disturbance, as much as a single leaf falling, and jump with little provocation (JAC pers. obs.). This is one of a handful of Neduba species that drum ( Weissman 2001 ; see also N. castanea , N. macneilli , and N. lucubrata below). Drumming was observed in captivity by a single male without a female present (JAC pers. obs) and not in the field; the context of drumming in the mating system is not known in this species.