Neoconocephalus spiza Walker and Greenfield, 1983

Piotr Naskrecki, 2000, Katydids of Costa Rica / Vol. 1, Systematics and bioacoustics of the cone-head katydids (Orthoptera: Tettigoniidae: Conocephalinae sensu lato)., Philadelphia, PA: The Orthopterists Society at the Academy of Natural Sciences of Philadelphia, : 62-63

Neoconocephalus spiza Walker and Greenfield, 1983

Figs. 13 G-H, 44F-G, 45D, 56E-G, Map 8

1983 Walker and Greenfield, Trans. Amer. Ent. Soc. 109: 385; type locality: Panama, Gamboa; type

depository: Florida State Collection of

Arthropods, Gainesville – holotype male

Note: Some Costa Rican specimens identified in this work as N. spiza may, in fact, represent a new, undescribed species. Although morphologically indistinguishable, and with the general song structure resembling that of individuals from Panamanian populations, the structure of individual chirps of the call differ significantly from “typical” N. spiza . All individuals of N. spiza from numerous localities in Panama and northern Costa Rica produce chirps with a distinctive pulse structure and chirps are seldom produced at a very regular rate for very long (usually no longer than several seconds, or 8-10 chirps; this applies to both chorusing and solo individuals) (Greenfield, pers. comm.). Contrastingly, individuals from southern Costa Rican populations (Osa Peninsula, Valle de Coto Brus) produce chirps without a recognizable pulse structure and chirps are produced at very regular rate for long periods of time.

On the other hand, Greenfield (pers. comm.) suggests that N. spiza may be a species exhibiting a considerable inter-population variation in the song structure, and the differences between southern Costa Rican and Panamanian populations are due to such local variations. A similar suggestion was made by Walker and Greenfield (1983) with regards to N. saturatus (Griffini) from Trinidad.

For the purpose of this work, I will treat the southern Costa Rican population as a possibly separate, unidentified species (it will be further referred to as N. cf. spiza ), closely related to N. spiza , without officially describing it as new, pending a more thorough analysis of a larger sample of specimens and recordings. The description below is based on Costa Rican specimens of N. spiza displaying acoustic behavior similar to that of Panamanian populations of this species.

Diagnostic description.— General characteristics as described above. Stridulatory file of male 1.8-2.3 mm long, with 68-96 teeth; file strongly but gradually narrows towards proximal end ( Figs. 44 F). Mirror of stridulatory apparatus oval ( Fig. 45 D). Fastigium of vertex separated from fastigium of frons by distinct gap; ventral fastigial tooth prominent ( Fig. 13 H); frontal portion of fastigium with light band, usually accompanied by black band below; often (especially in brown specimens) entire ventral portion of fastigium black ( Fig. 13 G).

Mid femur with 1-2 small spines on anterior ventral margin, never accompanied with black spots at their bases; fore femora occasionally unarmed ventrally. Brown individuals often with dark stripe on tegmina, continuous with darker lateral lobes of pronotum.

Ovipositor slightly longer than hind femur (ratio ovipositor/hind femur 1.16-1.22), straight. 1.08), straight.

Measurements.— Table 7 .

Bioacoustics.— N. spiza and N. cf. spiza are the only Costa Rican species of the genus with a call consisting of individual, discontinuous chirps. Individuals from northern Costa Rica (Santa Rosa National Park) exhibit calling behavior indentical to that of Panamanian populations of N. spiza . Their call consists of long sequences of chirps produced at the rate of about 3-5/s (at 27°C), each chirp (pulse train) lasting 30-32 ms (avrg. 45±72, n=50). The chirps have recognizeable structure ( Fig. 56 G). Walker and Greenfield (1983) measured the wingstroke rate of individual chirps of N. spiza at ca. 150/s, with 6-8 wingstrokes per chirp. The peak of energy of the call is located between 10 and 11 kHz. Individuals from southern Costa Rica produce chirps at the rate of 3.2/s at 24°C ( Fig. 56 E) and unlike N. spiza from Panama ( Fig. 56 G), individual chirps have no recognizable structure ( Fig. 56 F). The stridulatory file in both forms is similar ( Figs. 44 F-G).

Costa Rican individuals of both N. spiza and N. cf. spiza call both at night and during the day. Greenfield (1988) demonstrated that males of N. spiza will cease their calling if other species of the genus call nearby, and females stop moving towards the singing male if congeneric males also sing. In places where populations of congeners are high, males of N. spiza will switch their calling periodicity from nocturnal to entirely diurnal. This behavior is presumably caused by the avoidance of energy wasted on calling while the females cannot be attracted. It is yet unknown if such behavior occurs also in the Costa Rican population.

Distribution.— N. spiza has been previously known only from Panama. These are the first records of this species from Costa Rica. Like other species of the genus, it occurs in a variety of open, grassy habitats.

Material examined ( N. spiza ).— COSTA RICA: Alajuela Prov., Caño Negro, R.N.V. S Caño Negro, elev. 20 m, 8 - 24 August 1992 (coll. K. Flores) - 1 male ( INBio); Puesto Playuelas, Caño Negro, R.N.V.S. Caño Negro, elev. 20 m, 26 February 1993 (coll. K. Martínez) - 1 female ( INBio); Cartago Prov., 2 mi SE Turrialba (grounds of Inst. Interamer. de Sci. Agricolas), 1 - 3 October 1961 (coll. Hubbell, Cantrall, Cohn) - 1 male ( UMMZ); Guanacaste Prov., Estac. Murciélago, 8 km SO de Cuajinquil, 18 September 1993 (coll. F. Quesada) - 1 female ( INBio); Estac. Pitilla, 9 km S. Santa Cecilia, elev. 700 m, 15 April 1994 (coll. C. Moraga) - 1 female ( INBio); Estac. Pitilla, 9 km St. Cecilia, elev. 700 m, 15 November 1988 (coll. GNP Biodiversity Survey) - 1 female ( INBio); Estac. Pitilla, 9 km S Santa Cecilia, elev. 700 m, 22 August 1993 (coll. C. Moraga) - 1 male ( INBio); Finca Jenny, 30 km N Liberia, elev. 300 m, 27 March 1993 (coll. F. Araya) - 1 female ( INBio); same locality, elev. 240 m, 15 January 1994 (coll. F. Araya) - 1 female ( INBio); Finca Jenny, 30 km N Liberia, P.N. Guanacaste, elev. 300 m, 25 February 1993 (coll. F. Araya) - 1 female ( INBio); Los Almendros, P.N. Guanacaste, 24 April 1992 (coll. G. Gallardo) - 1 female ( INBio); same locality, 3 November 1993 (coll. K. Martínez) - 1 female ( INBio); Río San Lorenzo, Tierras Morenas, Z.P. Tenorio, elev. 1050 m, 15 July 1991 (coll. C. Alvarado) - 1 female ( INBio); same locality, elev. 1050 m, 21 April 1992 (coll. C. Alvarado) - 1 female ( INBio); Heredia Prov., Finca Naranjo Valenciana, 2 km S Pueblo Nuevo, Sarapiquí, elev. 90 m, 22 August 1992 (coll. M. Ortiz) - 2 males ( INBio); Puntarenas Prov., P. N. Manuel Antonio, Quepos, 20 August 1993 (coll. G. Carballo) - 1 female ( INBio); San José Prov., Estac. Zurquí, 500 m antes de Tunel, elev. 1600 m, 15 April 1991 (coll. G. Maass) - 1 female ( INBio)

Material examined ( N. cf. spiza ).— COSTA RICA: Puntarenas Prov., Península de Osa, Corcovado N. P., Estac. Sirena , 12 August 1980 (coll. D.H. Janzen and W. Hallwachs) - 1 female ( INBio); Península de Osa, Rancho Quemado , elev. 200 m, 15 July 1992 (coll. M. Segura) - 1 male, 2 females ( INBio); same locality, elev. 200 m, 15 August 1992 (coll. M. Segura) - 1 female ( INBio); same locality, elev. 200 m, 15 November 1992 (coll. R. Aguilar, M. Segura and F. Quesada) - 1 female ( INBio); Sirena, Corcovado N.P., elev. 0 - 100 m, 15 February 1990 (coll. G. Fonseca) - 1 female ( INBio); same locality, elev. 0 - 100 m, 10 - 25 August 1992 (coll. A. Gutiérrez) - 1 male ( INBio); Valle de Coto Brus, Las Cruces, Wilson Botanical Gardens, elev. 700 - 1000 m, 1 - 6 December 1995 (coll. P. Naskrecki) - 2 males ( PN collection).

Figures

FIG. 13. Frontal and lateral view of fastigia of Costa Rican Neoconocephalus spp. A-B. N. triops, C-D. N. punctipes - form without a fastigial gap, E-F. N. punctipes - form with a fastigial gap, G-H. N. cf. spiza.

FIG. 44. Stridulatory files of Costa Rican species of Neoconocephalus. A. N. affinis, B. ditto, enlarged fragment, C. N. triops, enlarged fragment, D. ditto, entire file, E. N. punctipes, entire file, F. ditto, enlarged fragment, G. N. cf. spiza, enlarged fragment, H. ditto, entire file.

FIG. 45. Stridulatory areas of Costa Rican species of Neoconocephalus, dorsal views, left and right sides. A. N. affinis, B. N. triops, C. N. punctipes, D. N. spiza.

FIG. 56. Oscillograms of male airborne calls and substrate tremulations of species of Neoconocephalus. A. N. affinis, B. ditto, 0.5 s fragment, C. N. punctipes, D. ditto, 0.5 s fragment, E. N. cf. spiza (Costa Rica, Heredia Prov., Las Selva Biol. Sta.), F. ditto, 0.5 s fragment, G. N. spiza (Panama, Gamboa).

MAPS 7 - 12. Distribution of species of Conocephalinae s. l. in Costa Rica. 7. Neoconocephalus affinis, N. triops, 8. Neoconocephalus punctipes, N. cf. spiza, 9. Bucrates capitatus, B. clausus, Metacaputus brenesi, 10. Pyrgocorypha rogersi, P. hamata, 11. Caulopsis cuspidata, C. microprora, 12. Moncheca elegans, M. pretiosa, Vestria punctata.