Wild Silk Moths

Saturniidae. Giant silk moths, saturnians.

These elegant moths inspire admiration and awe because of their great size (WS up to 20 cm, as in Arsenura ponderosa) and sumptuous color designs on broad wings. They are most often seen around electric lights, to which most are strongly attracted. Males bear highly developed, featherlike antennae that are extremely sensitive to the airborne molecules of the female sexual pheromones. With these organs, they may detect a female over a distance of several kilometers and fly upwind to find her. The female's antennae may also be feathered (but much less so than the male's) or merely pectinate or simple.

Adults of all species lack functional mouthparts and do not feed, relying on the food stores accumulated by their voracious larvae. Saturniid caterpillars are robust (some immense), obese creatures when mature. Most bear rows of swollen tubercles or spines, the latter often tipped with urticating barbs or hairs that can cause painful skin rashes on the human skin. Food plants are extremely diverse, even within species, and belong to such disparate families as Anacardiaceae, Rubia-ceae, Fabaceae, and Flacourtiaceae for the Neotropical species.

Prior to pupation, saturniid caterpillars commonly spin a rigid, silken cocoon that is suspended from the branches or leaves of the host plant or placed in refuse on the ground (Raymundo 1919); many pupate without silk in an earthen cell. The shape of cocoons is characteristic of the species, as is the quality and quantity of silk incorporated into them. Those of one species (Rothschildia aurota) have even been produced under culture for their silk, although not very successfully. It is much coarser and therefore not as desirable as that from the domestic silk moth (Bombyx mori). The latter belongs to a distinct family (Bombycidae) and has been cultivated in various parts of Latin America, with varied success.

Saturniids utilize several strategies of defense, including simple cryptic pattern (Loxolomia), distastefulness, which is signaled by brightly colored organs (Dirphia), toxic abdominal hairs (Hylesia, female only), and elaborate threat displays involving false eyespots (Automeris) (Blest 1960). Many species experience high levels of parasitism in the larval and pupal stages from chalcid wasps, tachinid flies, and others, against which their protective ploys seem to have little effect.

There are more than 800 species in the region (Lemaire pers. comm.), most of which are broadly reviewed in the works of Lemaire (1978) and Michener (1952). Some local treatments of saturniid faunas (Janzen 1982, Lemaire and Venedictoff 1989) contain useful biological and zoo-geographic information as well as present a cross section of the types found in the Neotropics.

References

Blest, A. D. 1960. A study of the biology of saturniid moths in the Canal Zone Biological Area. Smithsonian Ann. Rep. 1959: 447-464. Janzen, D. H. 1982. Guía para la identificación de mariposas nocturnas de la familia Saturni-idae del Parque Nacional Santa Rosa, Guanacaste, Costa Rica. Brenesia 19/20: 255-299. Lemaire, C. 1978. Les Attacidae Américains. (The Attacidae of America [= SaturniidaeJ: Attacinae.) C. Lemaire, Neuilly-sur-Seine. Lemaire, C., and N. Venedictoff. 1989. Catalogue and biogeography of the Lepidoptera of Ecuador. I. Saturniidae. With a description of a new species of Meroleuca Packard. Allyn Mus. Entomol. Bull. 129: 1-60. Michener, C. D. 1952. The Saturniidae (Lepidoptera) of the Western Hemisphere: Morphology, phylogeny and classification. Amer. Mus. Nat. Hist. Bull. 98: 335-502. Raymundo, B. 1919. Noticia sobre alguns lepidópteros serígenos do Brasil. Rev. Tribunals, Rio de Janeiro.

Regal and Imperial Moths

Saturniidae, Ceratocampinae

(= Citheroniinae), Citheronia and Eacles. Portuguese: Caveiras (Brazil). Horned devils (larvae).

One provocative common name of regal moths (Citheronia), "horned devils," comes from the appearance of their larvae. These giant (BL to 10 cm), varicolored (often orange or red), fearsome creatures have enormous, curved, hornlike protuberances on all the thoracic segments (fig. 10.1b). The naked skin is marked with contrasting oblique bars or other strongly contrasting patterns. The natural host plants are not entirely known, but larvae of various species have been found on wild cotton and Pinus and reared in captivity on Peruvian pepper (Schinus molle, Anacardiaceae).

These two genera are the showiest of around 160 neotropical species in the subfamily. Adult Citheronia (fig. 10.1a) are fairly large, stout moths (WS 8-10 cm) with rich umber bodies and hind wings; the ground colors of the fore wings are gray to black, the veins reddish-brown and the intervenous areas marked with elongate to oval white or cream spots. The abdominal segments are thinly banded by cream basally. The fore wings tend to be somewhat more elongate in this genus, in contrast to the broader, slightly falcate wings of Eacles, imperial moths. Adults of Eacles also often have more blotched wing patterns and faint ocellar spots in the middle of each wing, although they are otherwise very similar in most of the species (fig. 10.1c). Some also are strongly yellow at the base of the wing.

Figure 10.1 WILD SILK MOTHS (SATURNNDAE). (a) Regal moth (Citheronia laocoon), male, (b) Regal moth, larva, (c) Imperial moth (Eacles imperialis decoris). (d) Window-winged saturnian (Rothschildia Orizaba), male, (e) Window-winged saturnian, larva, (f) Window-winged saturnian, cocoon. (g) Copaxa (Copaxa lavendera).

Figure 10.1 WILD SILK MOTHS (SATURNNDAE). (a) Regal moth (Citheronia laocoon), male, (b) Regal moth, larva, (c) Imperial moth (Eacles imperialis decoris). (d) Window-winged saturnian (Rothschildia Orizaba), male, (e) Window-winged saturnian, larva, (f) Window-winged saturnian, cocoon. (g) Copaxa (Copaxa lavendera).

The larvae of imperial moths are little different from those of Citheronia except for a lack (in most but not all) of the hornlike processes on the first thoracic segment and the presence of very evident, fairly long, white body hairs (in some but not all). Natural food plants for these are also mostly a mystery, but a few are known to be broad-leaved trees and shrubs, Pinus, and Cochlospermum, although the larvae thrive on many kinds of woody plants, including cultivated varieties such as guava, Spondias, and many others.

About 20 species of Citheronia and 16 species of Eacles occur throughout Latin America (Lemaire 1988).

Reference

Lemaire, C. 1988. The Saturniidae of America: Ceratocampinae. Ed. C. Lemaire, Neuilly-sur-Seine.

Window-Winged Saturnians

Saturniidae, Saturninae, Saturnini, Rothschildia. Spanish: Cuatro ventanas. Nahuatl: Itzpapalotl (Mexico).

Large, translucent, triangular or oval areas in each wing immediately identify this genus of large (WS 11-13 cm) saturnians (fig. 10.Id, pi. 2c). The wings otherwise display rippling shades of soft brown, broken by an irregular white line traversing both fore and hind wing just outside the triangles. The wings also have light mar gins. The abdomen is marked laterally with a chainlike series of white spots.

Approximately twenty-five species are known, occurring from Mexico to Argentina. Sixteen species dwell in Andean mountain forests (Lemaire 1978). Some confusion in their identification is caused by environmentally controlled color polymorphisms (Janzen 1984). Rust-colored or chocolate forms of a few species occur. The time of flight of these generally follow seasonal shifts in background color, against which the moths are cryptic. During hot, dry conditions, when the vegetation is relatively pale, bleached, or sparse, those with the lighter shade are seen; when cool, wet conditions prevail, and lush, deep green leaves are abundant, the darker types are present.

Mature larvae (fig. 10. le) are large (79-85 mm), mostly green, some with light segmental rings or bands, transverse black bars, or a light-colored longitudinal ridge running along the sides; the typical saturnian tubercles are usually present but very small and bear harmless spines. They feed on a wide variety of deciduous trees and shrubs in nature, including Spondias, Jatropha, Sapium, Baccharis, Croton, and Jacaranda. They also are minor pests on cultivated plants, such as manioc, cashew, and castor bean (Ricinus communis), and can be reared on many common garden trees, including willow, ash, Prunus spp., and

Ligustrum (d'Almeida 1957; Urban and Lucas de Oliveira 1972). As with most large saturnians, the mortality rate in natural populations is very high, nearly 90 percent in a Salvadoran species studied by Quezada (1967).

The cocoons (fig. 10.If) are hard and suspended by a petiole attached to one side of the upper end. Cocoons of R. aurota were once utilized as a source of commercial silk in Brazil (Girard 1874, Ribeiro 1948).

To the Aztecs of central Mexico, these moths were identified with fire because of the gray, wedge shape wing spots that reminded them of obsidian or flint (with which fire is started) and called itzpapâlotl (;itzlis = flints + papâlotl = moth). The moth's undulating flight and wavy lines in the wing pattern were also likened to the dancing flames. Evidence for this symbolism is found in numerous bas-reliefs and designs (see fig. 1.11) found in the architecture of these people (Hoffmann 1918).

References d'Almeida, R. F. 1957. Brevas notas sôbre o gênero Rothschildia Grote, 1897 (Lepidoptera, Saturniidae). Mus. Nac. Rio de Janeiro Bol. (Nov. Ser.) 171: 1-47. Girard, M. M. 1874. Le ver a soie Brésilien.

Soc. Acclimatation (Ser. 3) Bull. 1: 183-203. Hoffmann, C. C. 1918. Las mariposas entre los antiguos mexicanos. Cosmos 1. Unpaginated. Janzen, D. H. 1984. Weather-related color polymorphism of Rothschildia lebeau (Saturnidae). Entomol. Soc. Amer. Bull. 30: 16-20. Lemaire, C. 1978. Rothschildia Grote. In C. Lemaire, Les Attacidae Américains (The Attacidae of America [= Saturniidae]). Ed. C. Lemaire, Neuilly-sur-Seine. Pp. 29-103. Quezada, J. R. 1967. Notes on the biology of Rothschildia ? aroma (Lepidoptera: Saturniidae), with special reference to its control by pupal parasites in El Salvador. Entomol. Soc. Amer. Ann. 60: 595-599. Ribeiro, B. L. 1948. Contribuiçâo para o conhecimento da bionomia de "Rothschildia aurota" (Cramer, 1775) (Lepidoptera, Saturnidae). Rev. Brasil. Biol. 8: 127-141. Urban, D., and B. Lucas df. Oliveira. 1972. Contribuiçâo ao conhecimento da biologia de

Rothschildia jacobaeae (Lepidoptera, Saturniidae). Acta Biol. Paranaense 1: 35-49.

Copaxas

Saturniidae, Saturniinae, Saturniini, Copaxa. Spanish: Canelas (Peru).

This is a diverse genus of thirty entirely Neotropical, mountain-dwelling saturnians characterized by multiple transparent, rounded to elongate spots in the center of each wing (fig. 10. lg), or a simple spot (Lemaire 1978). The fore wings are usually falcate at the tip, especially in the male, and mostly uniform, somber, warm brown, variously broken by darker, straight lines running obliquely between the spots and wavy lines external to the hind wing spot. Most are fairly large (WS 9-13 cm) and are nocturnal fliers, often attracted to artificial light.

Not many immatures are described. The larvae of most feed on plants in the family Lauraceae, are cryptically colored, and are gregarious; the exception are larvae of Copaxa cydippe, who feed on pine, are bold green-and-white striped, and are solitary (Wolfe 1988). The larva of C. moinieri in Costa Rica is a green color very similar to that of the leaves of its food plant, Ocotea veraguensis (Lauraceae). It is spined but not urticating. Pupation occurs in an open mesh cocoon attached to a branch or leaf of the host well above the ground (Janzen 1982: 277-278). The fully grown larvae of C. decrescens from Brazil are also green, with a light lateral line; the young larvae are gregarious on the food plant, which is avocado (Persea americana, Lauraceae) (Dias 1988).

References

Días, M. M. 1988. Estágios ¡maturos de Copaxa decrescens Walker, 1855 (Lepidoptera, Saturniidae). Rev. Brasil. Entomol. 32: 263-271. Janzen, D. H. 1982. Guía para la identificación de mariposas nocturnas de la familia Saturniidae del Parque Nacional Santa Rosa, Guanacaste, Costa Rica. Brenesia 19/20: 255-299.

Lemaire, C. 1978. Copaxa Walker. In C. Lemaire, Les Attacidae Américains (The Attacidae of America [= Saturniidae]). Ed. C. Lemaire, Neuilly-sur-Seine. Pp. 147-205. Wolfe, K. L. 1988. Aspectos inusuales de la biología de Copaxa cydippe Druce (Lepidop-tera: Saturniidae). Fol. Entomol. Mexicana 75: 47-54.

Eyed Saturnians

Saturniidae, Hemileucinae, Hemileucini, Automeris and relatives. Portuguese: Olhos de pavâo (Brazil).

This is a group (Lemaire 1971-1974) of 180 large (WS 5-15 cm) and beautiful moths, almost all of which have a conspicuous eyespot in the center of each hind wing; the spot has a black center and is surrounded first by multicolored rings in various bright hues and then by one complete and two partial, wavy, concentric circles alternating with black (fig. 10.2a). In the best-known genus, Automeris (and also Automerella and Pseudautomeris), spot colors are bluish or pink but never red or orange, as is found in the other related genera comprising this group, such as Hyperchiria and Camelia. Most species inhabit mountain forests (between 600—800 m elevation); relatively few live in the warm lowlands. The fore wings are almost unicolorous buff, but most have a faint circular spot about halfway along the wing near the leading edge and a pair of diagonal bars running across the middle of the wing.

The larvae (fig. 10.2b, pi. 2d) are mostly green, usually with colored or black bands running along the back and sides; some have variegated color patches of cream or pink. In one common genus (Leucanella), the skin is solid black and the spines contrasting bright yellow. They are all densely clothed with branched spines, especially dorsally (in place of the usual tubercles of other Saturniinae), the fine branches of which are articulated and tipped with small spinules that are highly venomous to the touch. These caterpillars are catholic in their tastes, various species choosing trees and shrubs in several unrelated families. Some recorded hosts are coral trees (Erythrina), figs (Ficus), oaks (Quercus), Ceano-thus, pepper (Schinus), tamarind (Tamarin-dus), Hibiscus, and cashew (Anacardium) (Lemaire 1971-1974). Pupation occurs in a silken cocoon placed among leaves on the ground, among twigs, or in detritus.

At rest, these moths resemble dead leaves, their drab upper wings completely hiding the eye-mimicking pattern of the lower wings. If disturbed, they elevate the fore wings, suddenly exposing the false eyes. The behavior has been experimentally observed to cause fright in potential predators, which doubtlessly are intimidated by a supposed adversary larger than themselves (Blest 1957). Other protective devices include immobility ("playing dead") and production of noxious secretions from the abdomen, well developed in Hyperchiria,

Figure 10.2 WILD SILK MOTHS (SATURNIIDAE). (a) Eyed saturnian (Automeris illustris), male, (b) Eyed saturnian (Automeris sp.), larva, (c) Hylesia (Hylesia lineata), female, (d) Hylesia, larva, (e) Swallow-tailed moth (Copiopteryx semiramis banghaasi). (f) Dirphia (Dirphia avia).

and the abundant hairs on the body of most species (Blest 1963).

The adults remain inactive during the day, taking flight at night in pursuit of mates, oviposition, and dispersion, although males of at least three species are known to seek females during the late morning hours (Marquis 1984). They are often attracted to artificial light.

References

Blest, A. D. 1957. The function of eyespot patterns in the Lepidoptera. Behaviour 11: 209-256.

Blest, A. D. 1963. Longevity, palatability and natural selection in five species of New World saturniid moth. Nature 197: 1183-1186. Lemaire, C. 1971-1974. Révision de genre Automeris Hübner et des genres voisins, biogéographie, éthologie, morphologie, tax-onomie (Lep. Attacidae). Mus. Nat. Hist. Nat. Mem., Nouv. Ser. A, Zool. 68: 1-232, 79: 233-422, 92: 423-576. Marquis, R. J. 1984. Natural history of a tropical daytime-flying saturniid: Automeris phrynon Druce (Lepidoptera: Saturniidae: Hemileucinae). Kans. Entomol. Soc. J. 57: 529-533.

Hylesias

Saturniidae, Hemileucinae, Hemileucini, Hylesia. Spanish: Bichos quemadores (larvae).

Because of their small size for the family (WS 3 cm) and their usually uniform, drab, grayish coloration, members of this saturnian genus do not attract the attention their larger relatives do (fig. 10.2c). Some do have small or rudimentary eyespots and exhibit protective behaviors as adults and larvae that are worthy of considerable interest.

The caterpillars (fig. 10.2d) are covered with a thick growth of branching, venomous spines, the anteriormost of which is especially long. Individuals of some species are gregarious, and dozens are sometimes seen in tight communal masses on tree trunks during the day. This habit plus a head-flicking movement evoked in re sponse to sharp sounds, such as might be made by an approaching predator, enhance the use of the spines. The high-pitched whine of parasitic wasps hovering over them also causes this response and prevents oviposition by these perpetual enemies (Hogue 1972). Other species live communally within a silken pouch that also serves for pupation (see below). Communal larvae apparently move in procession toward dusk to the crown of the host plant for feeding.

The number of food plant species is large and varied. They are almost all trees belonging to such families and genera as Mapighiaceaae (Byrsonima), Fabaceae (In-ga), Bignoniaceae (Tabebuia), and Sapinda-caceae (Urvillea).

Pupation occurs in aggregations in silk pouches (Wolfe 1988) or singly amid leaf litter on the ground. The female deposits her eggs around twigs in a close, rounded mass of defensive nettling hairs pulled from her abdomen.

When they are disturbed from their resting places, the female moths fall over on their sides and recurve the abdomen strongly, erecting a dense field of poisonous hairlike scales on their dorsum, making them distasteful to birds and insectivorous mammals. The abdominal scales of the male are nontoxic; the female incorporates them into her egg masses for their protection (Lamy and Lemaire 1983).

Adults of Hylesia canitia (probably mis-identified; actually H. metabus, a notoriously bad urticator) have an especially bad reputation near the Caripito oil fields in the Orinoco delta, Venezuela. Sharp hairlike scales in the anal tufts of this species become easily detached and embedded in human skin. They are responsible for outbreaks of dermatitis ("butterfly itch," "Caripito itch") aboard tankers lying at anchor in the many channels. Lights at night attract large numbers of adults. The scales may be disseminated throughout the ship through its forced-air ventilation sys-

tem (Goethe et al. 1967). When abundant around electric lights during population peaks, they are occasionally the cause of mass dermatitis in the populations of various towns (Allard and Allard 1958). In French Guiana, this affliction is known as "papillonite."

The genus is well developed only in the New World tropics, where at least one hundred species have evolved (Janzen 1984). The most complete life history is known for the common Hylesia lineata as a result of studies by Daniel Janzen (1984) in Costa Rica.

References

Allard, H. F., and H. A. Allard. 1958. Venomous moths and butterflies. Wash. Acad. Sci. J. 48: 18-21.

Goethe, H., R. Brett, and H. Weidner. 1967. "Butterfly Itch," eine Schmetterlingsderma-tose am Bord eines Tankers. Zeit. Tropen-med. Parasit. 18: 5-15. Hogue, C. L. 1972. Protective function of sound perception and gregariousness in Hylesia larvae (Saturniidae: Hemileucinae). J. Lepidop. Soc. 26: 33-34. Janzen, D. H. 1984. Natural history of Hylesia lineata (Saturniidae, Hemileucinae) in Santa Rosa National Park, Costa Rica. Kans. Ento-mol. Soc. J. 57: 490-514. Lamy, M., and C. Lemaire. 1983. Contribution à la systématique des Hylesia: Etude au microscope électronique à balayage des "fléchettes" urticantes. Soc. Entomol. France Bull. 88: 176-192.

Wolfe, K. L. 1988. Hylesia acuta (Saturniidae) and its aggregate larval and pupal pouch. J. Lepidop. Soc. 42: 132-137.

Oirphias

Saturniidae, Hemileucinae, Hemileucini, "Dirphia. "

A group of closely related genera, informally known as "dirphias," are close relatives of the hylesias but are easily distinguished by their generally large size (WS up to 12 cm) and more elaborately patterned wings; there is usually a Y-shaped mark in the center of the fore wing of most species which is replaced by a small dot in the drably colored species (fig. 10.2f). Like hylesias, they curl their abdomen when molested, but, although hairy, they are not urticating. Rather, they are tough skinned and possess noxious body chemicals that repel attackers. This fact is signaled by bright red, orange, or yellow intersegmental bands on the abdomen which are exposed by the hyperextended dorsum. The antennae are also conspicuously colored and held erect during these warning displays.

Little is recorded regarding the imma-tures. Few have been reared, and this has been accomplished on substitute food plants. The natural hosts remain unknown, except for D. avia in Costa Rica whose hosts are Cedrela odor ata and Hymenaea courbaril (Janzen 1982). The moderately large (BL 7— 10 cm) larvae of dirphias are very similar to those of eyed saturnians and hylesias in their rich adornment of spines with radiating branches, all with venomous tips. They may (Janzen 1982:274) or may not be gregarious in the later stages, however. Ground colors of the body are from black or brownish to light gray, and they are often dark lined or marked with blotches. Pupation occurs singly in a flimsy, papery cocoon among dry leaves on the ground (Gardiner 1974) or in the ground in a cell (Paradirphia).

References

Gardiner, B. O. C. 1974. The early stages of various species of the genus Dirphia (Saturniidae). J. Res. Lepidop. 13: 101-114. Janzen, D. H. 1982. Guía para la identificación de mariposas nocturnas de la familia Saturniidae del Parque Nacional Santa Rosa, Guanacaste, Costa Rica. Brenesia 19/20: 255-299.

Tailed Saturnians

Saturniidae, Arsenurinae (= Rhescyntinae).

This is a varied group, with a series of species displaying longer and longer taillike extensions from the apex of the hind wing. The tails are small and triangular in Arsenura males (giving the hind wing a truncated outline posteriorly), moderately long and square-tipped in Dysdaemonia males, still longer and curved outward in Paradaemonia, and extremely long and slender, with gnarled, spatulate tips in Copi-opteryx (fig. 10.2e), the so-called swallow-tailed moths. Others generally lack any suggestion of a tail at all (Loxolomia and Rhescyntis). All are large, some extremely so (WS to 20 cm), and with leaflike or harlequin patterns of buff, dark brown, and other subdued colors. Both fore and hind wings in Dysdaemonia have small, paired, round, transparent windows.

The subfamily is exclusively Neotropical and contains about fifty-seven species (Lemaire 1980) that range from Mexico to northern Argentina and southeastern Brazil. Most species are decidedly tropical, occurring below 1,500 meters mainly in Amazonia and southern Brazil.

The early stages of only a few species have been discovered. Younger larvae are adorned with a complete set of hornlike tubercles, those dorsolaterally on the third thoracic segment and the single dorsal one of the eighth abdominal segment being especially large. As they grow, the smaller tubercles disappear, but the larger develop into great protuberances. All arrive at maturity unarmed, losing their tubercles at the last molt. Recorded food plants are Virola (Myristicaceae) for Rhescyntis (Vázquez 1965); Annona, Bombax, Chorisia, and Bombocopsis for others (Janzen 1982, Martins Dias 1978). The pupa lies in an earthen cell unprotected by a cocoon.

The Power Of Charisma

The Power Of Charisma

You knowthere's something about you I like. I can't put my finger on it and it's not just the fact that you will download this ebook but there's something about you that makes you attractive.

Get My Free Ebook


Post a comment