Eriolus

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, : 111-113

ERIOLUS Bolivar, 1888

1888 Bolivar, Mem. Soc. Zool. France 1: 150; type species: Eriolus caraibeus Bolivar, 1888

1999 Naskrecki and Otte, Illustr. Cat. Orthop. I (CD ROM) >>full references

Diagnosis

Body small as for the subfamily, slender; both sexes macropterous ( Figs. 30 A, 31A, 37C). Head with fastigium of vertex 0.8-1.5 times as long as diameter of eye, sharply conical or blunt. Head narrow, frons flat or weakly convex; genae without lateral carinae. Prosternum unarmed or armed with two spines. Male cerci and concealed genitalia extremely variable, titillators always well developed; male paraprocts modified into long, finger-like processes; 10th tergite in both sexes often with long, narrow lobes on posterior margin; ovipositor moderately to strongly curved upwards, pointed apically.

Description (male except where specified)

Head.— Fastigium of vertex small as for the subfamily, 0.8-1.5 times as long as diameter of eye ( Figs. 30 C, 31C); fastigium sharply conical, with lamelliform, ventral keel, or blunt apically and rounded underneath; dorsal surface of fastigium smooth or with weak longitudinal furrow; lateral ocelli well developed; fastigium of vertex continuous with fastigium of frons. Antennal sockets separated by distance equal to about 0.4 diameter of eye. Eyes globose, moderately projecting; frons flat or weakly convex; genae with lateral carinae. Labrum and mandibles symmetrical to weakly asymmetrical (right mandible smaller) ( Fig. 30 B).

Thorax and wings.— Dorsal surface of pronotum smooth, flat; anterior margin of pronotum straight, posterior margin straight or weakly convex; lateral lobes with posterior angle narrowly rounded, with well developed humeral sinus. Thoracic auditory spiracle large, elliptical, completely hidden under lateral lobes of pronotum; posterior margin of spiracle with finger-like projection. Prosternum unarmed or armed with two, thin, widely separated spines, meso- and metasternum unarmed, without well developed basisternal lobes.

Wings in both sexes fully developed, surpassing apices of hind femora . Stridulatory apparatus of male well developed; stridulatory file straight or weakly sinusoidal ( Figs. 50 D-F), teeth relatively thick and narrow to very thin and wide; stridulatory area of left wing without secondary venation, rectangular or nearly triangular; mirror of right wing rectangular to nearly triangular, with very well developed veinlet next to AA 1. Posterior margin of front wing straight or weakly convex; apex of front wing narrowly rounded.

Legs.— Fore coxa with an elongate, sometimes laterally flattened, forward projecting spine dorsally; middle and hind coxa without spine; all trochanters unarmed. All femora unarmed dorsally but with small spines on anterior ventral margins, posterior ventral margins unarmed; genicular lobes of all femora armed with long spines, sometimes posterior lobes of fore and/or mid femora unarmed. Front and mid tibia unarmed dorsally, their ventral margins with short, immovable spines; tympanum on fore tibia bilaterally closed, tympanal slits facing forward, tympanal area moderately swollen; 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 often with hind margin bearing two, widely separated, narrow lobes ( Fig. 30 D); female 10th tergite similar to that of conspecific males, often with a pair of long, narrow, lobes; supraanal plate in both sexes small, broadly rounded apically; male cercus variable but always with one or two inner, blunt spines; spines basal, subapical or apical; paraprocts modified into long, finger-like processes ( Figs. 30 D, 31D, 32A, 32E); female cercus, simple, narrowly conical. Subgenital plate of male with a very shallow apical emargination; with or without styli; female subgenital plate approximately triangular, with shallow apical incision and sometimes with small lobe in the middle of apical incision. Male internal genitalia extremely variable but always with well developed titillators ( Figs. 30 E-F, 31E, 32D, 32G). Ovipositor narrow, moderately to strongly upcurved, its margins usually parallel; both dorsal and ventral margins of ovipositor smooth, its apex pointed; ovipositor always shorter than hind femur ( Figs. 30 A, 31A, 32B, 32F).

Coloration.— General coloration pale green ( Fig. 37 C); face green, sometimes clypeus and labrum brown; pronotum sometimes with two thin, light stripes along dorsal edges, and darker, brown or reddish markings in metazona; tegmina sometimes with irregularly distributes small, black dots.

Remarks.— The genus Eriolus was originally described to include only one species, Erioloides caraibeus Bolivar from Cuba. Subsequent authors included in this genus numerous additional, often unrelated species. Hebard (1927) moved 4 of these species ( E. consobrinus Pictet et Saussure , E. frater Redtenbacher , E. mexicanum Saussure , E. spiniger Redtenbacher ) to a new genus, Erioloides . He also indicated the possibility that some other species ( E. jamaicensis Bruner, E. longipennis Redtenbacher ), unknown to him, may also belong to his new genus. Erioloides longipennis is formally transferred to Erioloides in this work, while E. jamaicensis will be treated in an upcoming revision of the genus Erioloides and related genera (Naskrecki and Cohn, in prep.). Having exam- ined the holotype of Eriolus nigrifrons Karny, I came to the conclusion that it is more closely related to the genus Vestria than Eriolus , and is here formally transferred to the former.

In Costa Rica, the genus Eriolus is represented by 4 species. Both males and females can be easily identified to species based on their unique genitalic characters. Nothing is known about the biology and acoustic behavior these species. They sometimes come to light and most of them were collected by canopy fogging in primary, lowland wet forests.

Figures

FIG. 29. Species of Pluviasilva. A, C, F-J. P. levis: A. male - habitus, C. ovipositor, F. male cerci, lateral view, G. male cerci, dorsal view, H. titillators, I. male head and pronotum, dorsal view, J. male face; B, D-E. P. mexicana: B. male - habitus, D. male cerci, lateral view, E. male cerci, dorsal view.

FIG. 30. Eriolus aculeus. A. female - habitus, B. female face, C. female head and pronotum, dorsal view, D. male cerci, dorsal and posterior views, E. epiphallus, posterior and lateral views, F. titillators.

FIG. 31. Eriolus duplidentis. A. female - habitus, B. female face, C. female head and pronotum, dorsal view, D. male cerci, dorsal and posterior views, E. titillators.

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. 50. Stridulatory files of Costa Rican species of Conocephalinae s. l. A. Erioloides longinoi, C. Erioloides sikesi, C. Erioloides acutidentis, D. Eriolus duplidentis, E. Eriolus aculeus, F. Eriolus penicillus, G. Subria scutellaris, H. Subria crassicerca.