Katydids

Tettigoniidae. Spanish: Esperanzas (General), pulpones (Costa Rica), langostas verdes (Argentina), saltamontes nocturnos (Panama), grillos voladores (Peru). Portuguese: Esperanzas.

Katydids are also called long-horned grasshoppers and indeed resemble those orthop-terans except for their very long, many-segmented, whiplike antennae. They may be fully winged and capable of flight, or they may have very short wings, the hind wing completely lost and the fore wings stubby. When wings are present, an area at the base of the thickened fore wing is often modified in the males into a stridulatory or sound-producing organ. One wing has a roughened ridge (file), which is rubbed against an opposing sharp edge (scraper) on the other. The action sets both wings into rapid vibration and produces the fa miliar chirping, buzzing, lisping, clicking, or snapping sounds of these noisy creatures. Small tympana are located in slots on either side of the base of the front tibiae and in pockets on the sides of the thorax near the hind edge of the thoracic shield.

The female ovipositor may be strongly compressed for incising leaves and wood or valvelike for inserting eggs in the ground. Compressed forms are short and strongly curved or long and sword like.

This is a large family in Latin America, with some 1,350 known species; this number probably will increase by 30 percent or more ultimately (Nickle pers. comm.). The subfamilies may be recognized by use of Rentz's key (1979), which recognizes broader categories than Kevan's (1977) classification. Several new genera and species among the shield-backed katydids from Chile and Argentina have been added to the fauna by Rentz and Gurney (1985). They show affinities with others of the subfamily from Australia and western North America (ibid., 70).

The common English name of these insects derives from the song of the North American species, Pterophylla cam-ellifolia, which sounds like the plaintive phrase, "kate-she-did," "kate-did-she-did," or "katy-did." A folktale exists concerning the accountability of a fictitious lady in the death of a lover who spurned her. Local names in Spanish and Portuguese mean "hope," in reference to the green color of so many species in the family, the symbolic color of this emotion.

Katydids are an extremely important link in vertebrate food chains, as they are utilized by many birds, bats, monkeys, lizards, and snakes. Consequently, they have evolved a rich array of antipredator defenses (Belwood 1990). Forest katydids in Panama are major prey for foliage-gleaning bats. To some degree, the bats have adapted to reduced acoustic production by these katydids, who use an alternative form of communication ("substrate transmitted tremulation"), rather than the usual singing, to attract mates (Belwood and Morris 1987).

Like other orthopteroids, katydids possess a rich repertoire of defense tactics. A device not exhibited by others but used by the katydid Ancistrocercus in Costa Rica and Eremopedes colonialis in Mexico (Rentz 1972: 54) is association with wasps (Down-hoper and Wilson 1973).

References

Bei.wood, J. J. 1990. Anti-predator defences and ecology of Neotropical forest katydids, especially the Pseudophyllinae. In W. J. Bailey and D. C. F. Rentz, The Tettigoniidae: Biology, systematics and evolution. Springer, Berlin. Pp. 8-26. Bei.wood, J. J., and G. K. Morris. 1987. Bat pre-dation and its influence on calling behavior in Neotropical katydids. Science 238: 64-67. Downhoper, J. F., and D. E. Wilson. 1973. Wasps as a defense mechanism of katydids. Amer. Midi. Natur. 89: 451-455. Kevan, D. K. McE. 1977. Suprafamilial classification of "orthopteroid" and related insects; a draft scheme for discussion and consideration. Lyman Entomol. Mus. Res. Lab. (Mc-Gill Univ.), Mem. 4, Spec. Publ. 12: Appendix, 1-26.

Rentz, D. C. F. 1972. Taxonomic and faunistic comments on decticine katydids with the description of several new species (Orthop-tera: Tettigoniidae: Decticinae). Acad. Nat. Sci. Philadelphia Proc. 124: 41-77. Rentz, D. C. F. 1979. Comments on the classification of the orthopteran family Tettigoniidae, with a key to subfamilies and description of two new subfamilies. Austr. J. Zool 27: 991-1013. Rentz, D. C. F., and A. B. Gurney. 1985. The shield-backed katydids of South America (Or-thoptera: Tettigoniidae, Tettigoniinae) and a new tribe of Conocephalinae with genera in Chile and Australia. Entomol. Scandinavica 16: 69-119.

Broad-winged Katydids

Tettigoniidae, Pseudophyllinae.

Not all pseudophyllines have broad wings as their common name implies, nor are they leaflike as indicated by their scientific name. Perhaps a majority of the approximately 600 described Neotropical species are small to medium, spindle-shaped insects that sing little and do not look like leaves. The adults of members of some tribes, especially the following, do have very broad fore wings and closely resemble leaves.

Leaf Katydids

Tettigoniidae, Pseudophyllinae, primarily the tribe Pterochrozini. Spanish: Esperanzas hojas (General). Portuguese: Bichos folhas (Brazil).

Many katydids in this group of just under one hundred species appear incredibly like the leaves among which they live. They are green to brown in general color with an outline shape, even with drip tip, and markings imitating in every detail the color and structure of leaves, complete to midribs, side veins, and even transparent

Figure 5.1 BROAD-WINGED KATYDIDS (TETTIGONIIDAE). (a) Tanana (Thliboscelus hyperici-folius). (b) Eye-winged Katydid (Pterochroza ocellata). (c) Leaf katydid (Cycloptera speculata). (d) Long-winged leaf katydid (Cocconotus sp.).

and discolored areas resembling insect feeding holes, leaf miner tunnels, chewed edges, and mold spots (pi. 3g)!

This resemblance is further enhanced with behavior, for those species that dwell in living trees often walk with a slow undulating gait that makes them look like a leaf gently swaying in the breeze. Inhabitants of litter and dead vegetation tend to sit very still, angled on their sides and fitting perfectly with the brown, dried leaves on the forest floor. The latter tend also to be very large, approaching the sizes of the parts of plants they resemble. Celidophylla albimacula (BWL 8 cm) is a rare, gigantic species from Central America (Hogue 1979) with yellow-green wings which looks like a large withered leaf.

The principal genera are Pterochroza, Mimetica, Tanusia, Cycloptera, and Typophyl-lum (Vignon 1930). A Brazilian species made famous by Henry Walter Bates in the related tribe Pterophyllini, among which are also many leaf-shape forms, is the tanana (Thliboscelus hypericifolius = Chloro-coelus tanana; fig. 5.1a).

The males produce a very loud and not unmusical noise by rubbing together the overlapping edges of their wing-cases. The notes are certainly the loudest and most extraordinary that I ever heard produced by an orthopterous insect. The natives call it the Tanana, in allusion to its music, which is a sharp, resonant stridulation resembling the syllables ta-na-na, ta-na-na, succeeding each other with little intermission. It seems to be rare in the neighborhood. When the natives capture one, they keep it in a wicker-work cage for the sake of hearing it sing. (Bates 1892: 129)

Pterochroza ocellata (pi. lb) is an Amazonian species with greenish or brownish-red, brown-black-splotched fore wings that camouflage it well on dead leaves. But if this first line of defense fails, it fans out its hind w«ngs to display large threatening eyespots at their outer corners (fig. 5.1b). The leaf pattern is especially well developed in genera like Cycloptera (fig. 5.1c). When folded, the lower portion of the wings are often rolled under and hide the insect's abdomen. In repose, the tips of the fore wings project beyond or are equal to the length of the hind wings.

The nymphs are also leaf- or twiglike, often with very compressed bodies and flattened leg segments and erect crests on the back of the prothorax. They rest on the upper surfaces of leaves with their long legs spread spiderlike and bodies pressed close to the surface.

Because they are arboreal and nocturnal and so difficult to see even during the light of day, these katydids are seldom collected, and little is known of their biology. Those rare adults that come to artificial lights constitute the majority of specimens in museum collections.

Members of the related tribe Coccono-tini, primarily the genus Cocconotus (fig. 5.Id), are also large (BWL 8—9 cm) and have very long antennae, two to three times the body length. They habitually rest in rolled leaves of bananas, heliconias, gingers, cannas, and the like, head outward, only with the tips of the antennae exposed, testing the outside world while the rest of the insect remains hidden. They are mostly dark gray-brown and elongate, their wings rolled around the body.

Some members of the subfamily are wingless. A giant species found in the canopy of the Peruvian rain forest is Panoploscelus (tribe Eucocconotini). It is well protected by its great size and strength and sharply spined legs.

References

Bates, H. W. 1892. The naturalist on the River

Amazons. John Murray, London. Beier, M. 1960. Orthoptera, Tettigoniidae (Pseu-

dophyllinae II). Das Tierreich 74: 1—396. Beier, M. 1962. Orthoptera, Tettigoniidae (Pseu-

dophyllinae I). Das Tierreich 73: 1—468. Hogue, C. L. 1979. A third specimen of Celidophylla albimacula (Orthoptera: Tettigoniidae)

and remark on the emergence of Diptera from insect carrion. Entomol. News 90: 151. Vignon, M. P. 1930. Recherches sur les sauterelles-feuilles de l'Amérique tropicale. Première partie. Révision du groupe des "Pterochrozae" (Phasgonuridae, Pseudophyl-linae). Mus. Natl. Hist. Natur. (Paris), 6 Ser., Arch. 5: 57-214.

Narrow-winged Katydids

Tettigoniidae, Phaneropterinae.

Many of these katydids are leaf mimics but not quite so remarkably as those belonging to the broad-winged group (fig. 5.2d). The fore wings are generally longer and narrower and more plainly marked, green to brown. In a few species, the hind wings are brightly colored, such as Vellea, which has a broad scarlet zone basally. When the wings are folded, the tips of the hind pair project beyond the apices of the fore pair. Females have a globose head and short, upturned ovipositor. The outer part of the fore tibia in cross section is square and with a flat or slightly concave, dorsal surface. The thoracic auditory pockets are large and exposed.

Most narrow-winged katydids are medium-sized to small (BWL 25-50 mm), but Steirodon (formerly Peucestes) is gigantic (BWL 10—12 cm) and possesses a coarsely serrate corona around the periphery of the prothoracic shield (fig. 5.2a) (Nickle 1985). Nymphs of the genus are strongly compressed and have a conspicuous dark ocellate spot laterally, on the wing pad.

The group is phytophagous and arboreal. Some habitually rest on lichen-covered tree trunks, blending in perfectly on account of their own mottled white, green, and black body markings. The resemblance is increased by lobular excrescences on the legs and body exactly like the foliose form of the plant. An excellent example is Dysonia fuscifrons (fig. 5.2b) from Mexican cloud forests where the perpetually humid atmosphere supports a lush growth of epiphytes (Dampf 1939). Members of the tribe Pleminiini (e.g., Championica) are large, with mottled green and brown markings that camouflage them on moss- and lichen-covered tree bark where they habitually rest.

In Brazil, Scaphura and Aganacris (fig. 5.2c) mimic tarantula hawk wasps (Pepsis) and are not only colored the same, with deep blue body and rust or dark wings, but have a waspish attitude as well, walking jerkily and rapidly and waving their orange-tipped antennae. At the approach of danger, they also flutter their wings and turn up the abdomen in mockery of an attempt to sting.

The group is unique in possessing the only katydids whose females answer the calling songs of the males with a signal, though weak, of their own (Nickle and Carlysle 1975). The interval between the male and female sounds is important in determining the correct association and drawing the male to the female. The chro-

Figure 5.2 NARROW-WINGED KATYDIDS (TETTIGONIIDAE). (a) Giant narrow-winged leaf katydid (Steirodon sp.). (b) Lichen-mimicking katydid (Dysonia fuscifrons). (c) Tarantula hawk-mimicking katydid (Aganacris sp.). (d) Common leaf-mimicking katydid (undetermined).

niosomes of a number of Neotropical species of this subfamily have been described by Ferreira (1977).

The subfamily contains approximately 600 named species in Latin America.

References

Dampf, A. 1939. Un caso de fitomimetismo en un ortóptero Mexicano. Esc. Nac. Cien. Biol. Anal. 1: 525-533. Ferreira, A. 1977. Cytology of Neotropical : Phaneropteridae (Orthoptera-Tettigoniidae).

Genetica 47: 81-86. Nickle, D. A. 1985. A new steirodont katydid from Colombia (Orthoptera: Tettigoniidae). Entomol. News 96: 11-15. Nickle, D. A., and T. C. Carlysle. 1975. Morphology and function of female sound ! producing structures in ensiferan Orthoptera with special emphasis on the Phaneropte-rinae. Int. J. Ins. Morph. Embryol. 4: 159-168.

Cone-Headed and Meadow Katydids

Tettigoniidae, Conocephalinae, Copiphorini and Conocephalini.

j Many of these closely related groups of

¡ 140 to 150 species of katydids have power fully developed jaws adapted for seed eating or, in some cases, predation. Their name, however, derives from the strongly projecting anterior portion of the head; this may be only a simple convexity in meadow katydids (Conocephalini) or an elongate cone with a tubercle at its base

(this often notched below) in the cone-headed katydids (Copiphorini).

The meadow katydids, such as Conoce-phalus (fig. 5.3a), are relatively small (BWL seldom over 25 mm). They frequent marshes or verdant areas, usually living close to the ground and in aggregations. Their stridulatory activity is mainly diurnal or crepuscular. Cone-headed katydids are larger (BWL often 5—6 cm) and occupy diverse habitats, but many are associated with grasses whose seeds they eat. Their two-part songs (ticks, giving way to buzzes) are heard from dusk to dawn and are often of the chorusing type. Males stridulate for several hours each evening from exposed perches, apparently in sexual competition. Some nonsinging males also remain close to the singer, taking advantage of his call to steal confused females that come near (Greenfield 1983).

One South American cone-head, Copi-phora (fig. 5.3b), is fairly large (BWL 4—6 cm) and has bright blue, red, and yellow colors on the abdomen. These are brought into view when the insect is disturbed, usually by tipping the head down against the substratum and elevating the rear part of the body upward; the wings also may be opened or raised to better expose these colors, warning would-be predators of presumably noxious body fluids.

Neoconocephalus (fig. 5.3d) is another common Neotropical cone-head, whose large size (BWL 5-6 cm) and characteristic

Rflure 5.3 KATYDIDS (TETTIGONIIDAE). (a) Meadow katydid (Conocephalus sp.). (b) Multicolored katydid (Copiphora sp.). (c) Spike-headed katydid (Panacanthus sp.), nymph, (d) Cone-headed katydid (Neoconocephalus sp.).

loud, penetrating calls have made them attractive subjects for collectors and field studies of behavior (Greenfield 1990). Many of the species are barely distinguishable morphologically but can be separated readily by the distinctive sound patterns of the males (Walker and Greenfield 1983).

The enormous head of the nymph of the spike-headed katydid (Panacanthus; fig. 5.3c) has bulbous eyes and is grotesquely adorned with a peripheral crown of large teeth and a multispiked horn on the forehead. A South American genus, Coniun-goptera, has been recently added to the cone-head group (Rentz and Gurney 1985). It is associated with Nothophagus in the southern beech forests and is most closely related to an Australian genus, another example of an amphinotic distribution.

References

Greenfield, M. C. 1983. Unsynchronized chorusing in the cone-headed katydid Neocono-cephalus affinis (Beauvois). J. Anim. Behav. 31: 102-112.

Greenfield, M. C. 1990. Evolution of acoustic communication in the genus Neoconocephalus: Discontinuous songs, synchrony, and interspecific interactions. In W. J. Bailey and D. C. F. Rentz, The Tettigoniidae: Biology, systematics and evolution. Springer, Berlin. Pp. 71-97.

Rentz, D. C., and A. B. Gurney. 1985. The shield-backed katydids of South America (Or-thoptera: Tettigoniidae, Tettigoniinae) and a new tribe of Conocephalinae with genera in Chile and Australia. Entomol. Scandinavica 16: 69-119.

Walker, T. J., and M. D. Greenfield. 1983. Songs and systematics of Caribbean Neoconocephalus (Orthoptera: Tettigoniidae). Amer. Entomol. Soc. Trans. 109: 357-389.

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