Erioloides, Hebard, 1927

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, : 79-81

ERIOLOIDES Hebard, 1927

(Scimitars)

1927 Hebard, Trans. Amer. Ent. Soc. 53: 141; type

species: Eriolus consobrinus Pictet et Saussure, 1898 , by original designation

1999 Naskrecki and Otte, Illustr. Cat. Orthop. I (CD

ROM) >>full references

Diagnosis

Slender to quite robust; both sexes macropterous ( Figs. 19 A, 21A). Fastigium of vertex short, 1-1.5 times as long as diameter of eye; apex of fastigium blunt or acute. Head robust, frons flat or weakly convex; genae with weakly developed lateral carinae. Male cercus variable but nearly always biramose apically. Ovipositor unique, broad, with distinctly truncated apex ( Fig. 19 H).

Description (male except where specified)

Head.— Fastigium of vertex short, 1-1.5 times as long as eye diameter and 1-1.5 as wide as scapus; apex of fastigium blunt or acute; fastigium of vertex separated from fastigium of frons by small gap; occasionally fastigium of vertex with small ventral tooth at base; dorsal surface of fastigium smooth or somewhat rugose. Antennal sockets separated by distance equal to 0.3-0.5 diameter of eye. Eyes globose, weakly protruding. Frons flat or weakly convex; genae with moderately developed lateral carinae.

Thorax and wings.— Dorsal surface of pronotum smooth to moderately rugose, flat; anterior margin of pronotum straight, posterior margin straight or convex; lateral lobes with posterior angle rounded to almost acute. Thoracic auditory spiracle large, elliptical, completely hidden un- der lateral lobes of pronotum. Thoracic sterna unarmed.

Wings in both sexes fully developed, surpassing apices of hind femora by 1/6 to 1/2 their length. Stridulatory apparatus of male well developed; stridulatory file straight ( Figs. 49 A-F), with high number (160-230) of relatively very wide, lamelliform, closely spaced teeth; stridulatory area of left wing devoid of secondary venation; mirror of right wing rectangular or nearly square, with well developed veinlet next to AA 1. Posterior margin of front wing straight or weakly concave; apex of front wing narrowly rounded.

Legs.— Fore coxa with an elongate, forward projecting spine dorsally; middle and hind coxa without spine; all trochanters unarmed. Femora unarmed dorsally, but armed ventrally on both margins, sometimes posterior ventral margins of fore and/or mid femora unarmed; genicular lobes of all femora armed with sharp spines, occasionally lobes on fore and mid femora unarmed. Front tibia unarmed dorsally, both ventral margins with short, immovable spines; tympanum on fore tibia bilaterally closed, tympanal slits facing forward, tympanal area moderately swollen; middle tibia unarmed dorsally, ventrally armed on both margins; hind tibia armed on all four dorsal and ventral margins; apex of tibia with two pairs of ventral and one pair of dorsal movable spurs.

Abdomen.— Dorsal surface of abdominal terga smooth, unmodified. Male 10th tergite with surface smooth, its posterior margin weakly to distinctly incised, sometimes posterior margin of 10th tergite forming two pointed or rounded lobes; supraanal plate in both sexes small, broadly rounded apically; male cercus variable but nearly always biramose, rarely without subapical spine or lobe ( Figs. 19 D-E, 21D, 22B-J); titillators extremely variable, from flat, covered with cuticular scales and poorly differentiated from phallic membrane to well developed, needle-like; female cercus, simple, narrowly conical. Subgenital plate of male with well developed ventral keel and deep, triangular apical incision; styli short, 1.5-2.5 times as long as thick; female subgenital plate either triangular, with triangular apical incision, or much wider than long, with weakly emarginated apex. Ovipositor unique among Tettigoniidae , distinctly widened midlength, and with characteristic, obliquely truncated apex; apex thickened, heavily sclerotized; upper valvula usually with series of pegs or small teeth forming a file along its longitudinal axis, and with a similar series of pegs just below upper edge of valvula ( Fig. 19 H); ovipositor distinctly shorter than to as long as hind femur (ratio ovipositor/hind femur 0.6-1.1).

Coloration.— General coloration pale green; frons green, sometimes lower portion of frons brown or black; labrum sometimes black; mandibles black, brown, green to strikingly emerald green. Legs and abdomen green; tegmina often with contrastingly yellow venation.

Remarks.— The genus Erioloides is currently a subject of a taxonomic revision and phylogenetic analysis (Naskrecki and Cohn, in prep.). It includes over 20 species (both described and yet undescribed), distributed from Mexico, throughout the Caribbean and Central America, to the northern portion of South America. Below we redescribe 4 species known from Costa Rica and describe 4 new ones.

Little is know about the biology and behavior of the species of Erioloides . In Costa Rica, probably all species are exclusively arboreal and can be collected by canopy fogging or at lights. At La Selva Biological Station, nymphs of E. consobrinus have been collected from the tree Trema micranta (L.) Blume ( Ulmaceae ), and both nymphs and adults from the tree Virola koschnyi Warb. (Myristicaceae) . Erioloides consobrinus and E. longipennis frequently come to lights. Nothing is known about the natural diet of Erioloides spp. but in captivity they thrived for several months on a diet of various fruits and vegetables.

Little is known about the acoustic behavior of the species of the genus and only E. brevipennis has been recorded (see below). Females oviposit in plant tissues, using their highly modified ovipositor as a saw, making deep incisions in stems of various plants ( Fig. 37 A). Eggs are thin, spindle-shaped ( Fig. 38 C). In captivity, nymphs of E. longipennis hatched after about 3 weeks after oviposition.

Identification of species of Erioloides can be difficult, as many species differ only in details of the male concealed genitalia and the stridulatory apparatus. In many cases, females cannot be identified based on morphological criteria and can only be assigned to a species if collected with a male individual (the fact of occurrence at the same locality as a male is not evidence of conspecificity — frequently two or more species of Erioloides occur at the same location).

Figures

FIG. 18. Costa Rican species of Caulopsis. A, C-F. C. microprora: A. female - habitus, C. female face, D. female head and pronotum, dorsal view, E. male cerci, dorsal view, F. male cerci, posterior view; B. C. cuspidata - ovipositor.

FIG. 19. Erioloides longipennis. A. male - habitus, B. male face, C. male head and pronotum, dorsal view, D. male cerci, dorsal view, E. male left cercus - variation, dorsal view, F. titillators, posterior view, G. titillators, lateral view.

FIG. 20. Erioloides macrocephalus. A. male - habitus, B. male face, C. male head and pronotum, dorsal view, D. male left cercus, lateral view, E. male cerci, dorsal view, F. titillators, dorsal view.

FIG. 22. Costa Rican species of Erioloides. A. E. consobrinus - female, habitus, B. E. longinoi - male cerci, dorsal view, C. E. longinoi - male left cercus, lateral view, D. E. consobrinus - male cerci, dorsal view, E. E. consobrinus - male left cercus, lateral view, F. E. acutidentis - male cerci, dorsal view, G. E. acutidentis - male left cercus, lateral view, H. E. sikesi - male cerci, dorsal view, I. E. sikesi - male left cercus, lateral view, J. E. latiscobinus - male cerci, dorsal view, K. E. latiscobinus - male left cercus, lateral view.

FIG. 37. Costa Rican species of Conocephalinae s. l. A. Erioloides longipennis - female ovipositing, B. Erioloides longinoi - male, C. Eriolus penicillus - female, D. Conocephalus cinereus - male, macropterous form, E. Neoconocephalus triops - male, brown form, F. Sphyrometopa atlantica - male, inset - nymph.

FIG. 38. Eggs and cerci of Costa Rican species of Conocephalinae s. l. A-C. eggs, with enlarged fragments of the chorion: A. Copiphora rhinoceros, B. Lirometopum coronatum, C. Erioloides longipennis, hatched egg, D-F. male right cerci of Subria spp., dorsal views: D. S. sylvestris, E. S. scutellaris, F. S. crassicerca.

FIG. 49. Stridulatory files of species of Erioloides. A. E. longipennis, B. ditto, variation, C. E. macrocephalus, D. E. brevipennis, E. E. latiscobinus, F. E. consobrinus.