Moths And Butterflies

Lepidoptera.

This order is immediately recognized by the presence of minute scales on the wing membranes (the easily detached "dust" that imparts color to them) and a long, siphoning proboscis that coils up like a watch spring under the head when not employed in imbibing nectar and other liquids, such as the juices of rotting fruits (in some, the mouthparts are vestigial). Division of the Lepidoptera into butterflies ("Rhopalo-cera") and moths ("Heterocera") is a misleading, although useful, dichotomy. The former actually represent only one small side branch of the order that is specialized for diurnal existence. Correlated with flying in the sun are the expansive, often gaily colored wings, although the shade dwellers often have subdued or transparent wings. The larvae of most butterflies pupate in naked, suspended chrysalids, and the adults typically have knobbed antennae and lack a well-defined device for coupling the fore and hind wings. Moths, for the most part, are nocturnal and have relatively larger bodies with somber-colored wings. Their larvae pupate in cocoons or in cells in the ground, and most possess special structures for hooking the hind wing to the fore wing. Antennae are threadlike or plumed but rarely knobbed. These distinctions meet with many exceptions (many moths are brightly colored and diurnal, for example) but are generally adequate to characterize the groups, unequal and contrived as they may be.

Butterflies and moths exhibit many unusual behavioral traits as adults or larvae. The strange attraction of the latter to lights is still poorly understood (see moths, below). Adults of both groups also seek moisture and some nutrients from mud and moist sand (especially that laced with urine or soap residues), bird droppings, dung and carrion, rotting fruits and fungi, and even human perspiration. Butterflies are best known for this habit because of their visibility during the day, but moths of many kinds also "puddle" and siphon similarly unsavory liquids at night (Adler 1982, Becker 1983, Downes 1973). This activity is almost exclusively limited to males, which suggests a need for acquiring some substance (perhaps amino acids and sodium; Arms et al. 1974, Adler and Pearson 1982) of unknown importance in their sex lives.

Many adult butterflies and moths are known to require specific chemicals in their mating displays or to render them toxic or distasteful to predators (Brower 1984). The former are usually metabolized into volatile perfumes, dispersed from various secretory tissues (Barth 1960) at the base of hairlike scales located either on eversible organs on the body (coremata, chaetosemata) or directly on the wing surfaces (androconia). These substances are pyrrolizidine alkaloids that the insects obtain from droplets exuding from withered or injured plant tissues (Pliske 1975a). Such are greedily sought by many Ithomi-inae, Danainae, Ctenuchinae, and Arcti-

inae, which also are major pollinators of these plants (Pliske 19756). Species in the borage family (Heliotropium fedegoso, Tourne-fortia), the composite family (Eupatorium, Senecio), pea family (Crotalaria), and dogbane family (Parsonsia) are now known to provide these essential chemicals, but there may be others. A phenylacetaldehyde in the bladder flower (Araujia sericofera, As-clepiadaceae) also attracts moths (Cantelo andjacobson 1979).

Although the variety of lepidopteran colors and their arrangements are almost infinite, and the majority of these seem to act as camouflage, a great many otherwise segregate into basic types that are widely imitated among the families. These primary patterns are broadly recognized as follows: "tiger," basically orange with yellow, brown, red, and black streaks (pi. 3f); "red," generally deep orange, with oblique bars of black and yellow spots toward the apex of the fore wing; "blue," nearly all black (or bluish-black), often with broad, oblique fore wing or hind wing spots of red, blue, or green; and "transparent," clear or pale membranes and dark veins. These sometimes merge or overlap, and there are secondary types of all, such as the "zebra" striped variant of the "tiger," with simple alternating, longitudinal yellow or orange bars on a black background (zebra butterfly) or the "orange bordered" variant of the transparent which has broad, black-bordered margins to the wings (itho-miines), and others specifically resembling various models such as lycid beetles and vespid wasps. The latter "wasp types" with transparent, veined, or smoky wings may represent distinct categories evolved as Batesian mimics but are possibly related to the "transparent" and "blue" primary variants. All four possibly came into being, at least in butterflies, as imitations of other distasteful or stinging insects, but some researchers have postulated their origins as cryptic images, blending with the interplay of light and vegetation and the back ground against which the butterfly flies and is visible to predators (Papageorgis 1975). Transpareni forms fly in dappled sunlight near the ground in the un-derstory, yellow, black, and orange-striped (tiger) forms fly a bit higher (7—13 m), blue forms fly in the upper canopy, and orange and yellow forms fly above the canopy and at the forest margin.

A few patterns mimic nocturnal models and are apparently effective in obtaining protection for their bearers when at rest during the day: Opharus (arctiid moth) to Pyrophorus (elaterid beetle); Endobrachus revocans and relatives (megalopygid moths) and Cratoplastis (= Automolis) diluta (arctiid moths) to Achroblatta luteola (cockroach).

These patterns are employed widely in several unrelated families in Miillerian mimicry complexes with toxic or noxious chemical qualities: among the butterflies, these are commonly found in the Heli-coniinae, Ithomiinae, Danainae, Acrae-inae, Papilionidae, and more rarely, in the Riodininae, Nymphalinae, and Pieridae. The moth families with such colors are the Arctiidae (Ctenuchinae and Pericopinae), Zygaenidae, Dioptidae, Castniidae, and Agaristidae. The chemicals are usually cardiac glycosides and alkaloids obtained during the larval feeding periods (Rothschild 1972) or as adults (Brown 1984). They have an unpleasant, musky smell, even to humans, and are dissolved in yellow-colored body fluids that are bitter tasting. Like the adults, lepidopteran larvae exhibit a similar variety of defensive colors and patterns, mimetic and otherwise (Haviland 1925, Nentwig 1985). Toxic substances may also be contained in body fluids and tissues or produced by specialized poison glands (Quiroz 1978).

Lepidopterous larvae are the familiar caterpillars, with an elongate, cylindrical body equipped with several (usually four intermediate and one anal) pairs of stumpy walking legs in addition to small, segmented thoracic legs used primarily as aids in feeding. The integument is naked and smooth or variously adorned with fine to coarse hairs or elaborate horns or tubercles. The head may also bear a pair of long spines in butterfly caterpillars, but these are never present on the head of moth larvae, although a prothoracic pair will often project forward over the head and seem to arise from it. Caterpillars lead an absolutely different life from the adults and are much more ecologically diverse (Janzen 1988). Those of a large number of species are of agricultural importance when abundant on cultivated plants (Mar-gheritis and Rizzo 1965). They may be so numerous at times that their dry droppings fall like raindrops, making an audible patter on dry leaves on the ground.

Pupae are usually simple, drably colored, and hidden in most moths or variously shaped and colored to resemble leaves and other objects and suspended nude in the environment, as in the chrysalids of butterflies. Many tropical butterfly pupae are adorned with gold or silver markings that resemble reflective droplets of rainwater or dew.

The Lepidoptera form an immense order (one-tenth of all animal species) and are particularly well developed in the Neo-tropics (Heppner in press), where at least 50 percent of the world fauna resides (Holloway 1984). In addition to being divided into butterflies and moths, the order is often informally broken in "macro-lepidoptera" (families of larger species) and "microlepidoptera" (families of small moths, although many of these may actually be larger than some smaller macrolepi-doptera). There are an estimated 43,000 species of Neotropical macrolepidoptera (Watson and Goodger 1986). No complete identification work exists, although Seitz (1907—1939) covers most of some major groups of macrolepidoptera. The Atlas of Neotropical Lepidoptera (Heppner 1981—) is now being issued in parts and will ultimately provide illustrations and basic information on all the species. In addition to general entomology treatments (see chap. 1), works of fundamental significance are by Aurivillius and Wagner (1911-1939) and Forbes (1939, 1942). Some additional useful or popular general treatments are those of Bourquin (1945) and Raymond (1982).

Generally common and conspicuous, the Lepidoptera are the subject of much experimental research in the quest for knowledge of general biological principles (Silberglied 1977, Common 1970). Quite a number are of medical importance, both beneficially (source of drugs) and as pathological agents (urtication) (Lamas and Pérez 1987). The ubiquity and visibility of the order has also attracted the incorporation of certain species into the cultural practices of some Latin American peoples (Beutel-spacher 1989).

Adult butterflies and moths often have an entourage of parasitic or commensal mites living on their bodies (Treat 1975).

References

Adler, P. H. 1982. Soil- and puddle-visiting habits of moths. Lepidop. Soc. J. 36: 161-173. Adler, P. H., and D. L. Pearson. 1982. Why do male butterflies visit mud puddles? Can. J. Zool. 60: 322-325. Arms, K., P. Fenny, and R. C. Lederhouse. 1974. Sodium: Stimulus for puddling behavior by tiger swallowtail butterflies, Papilio glaucus. Science 185: 372-374. Aurivillius, C., and H. Wagner. 1911-1939. Lepidopterorum catalogus. Pts. 1-94. Junk, Berlin. Began publishing again in 1987 as "New Series," J. Heppner, ed., by Brill, Leiden.

Barth, R. 1960. Orgáos odoríferos dos Lepidópteros. Min. Agrie., Serv. Flor., Parq. Nac. Itatiaia (Rio de Janeiro) Bol. 7: 1-157. Becker, V. O. 1983. ¿Por que as borboletas se juntam nos lugares úmidos? Brasil Florestal 13(53): 49-50. Beutelspacher, C. R. 1989. Las mariposas entre los antiguos Mexicanos. Fondo Cult. Econ., Mexico. Bourquin, F. 1945. Mariposas Argentinas: Vida, desarrollo, costumbres y hechos cu-

riosos de algunos lepidópteros argentinos. Pub. by author, Buenos Aires.

Brower, L. P. 1984. Chemical defence in butterflies. In R. I. Vane-Wright and P. R. Ackery, eds., The biology of butterflies. Academic, London. Pp. 109-134.

Brown, Jr., K. S. 1984. Adult-obtained pyrro-lizidine alkaloids defend ithomiine butterflies against a spider predator. Nature 309: 707-709.

Cántelo, W. W., and M. Jacobson. 1979. Phenylacetaldehyde attracts moths to bladder flower and to blacklight traps. Environ. Entomol. 8: 444-447.

Common, I. F. B. 1970. Lepidoptera. In CSIRO, ed., The insects of Australia, a textbook for students and research workers. Melbourne Univ., Carleton. Pp. 765-866.

Downes, J. A. 1973. Lepidoptera feeding at puddle-margins, dung, and carrion. Lepi-dop. Soc. J. 27: 89-99.

Forbes, W. T. M. 1939. The Lepidoptera of Barro Colorado Island, Panama. Mus. Comp. Zool. (Harvard Univ.) 85(4): 97-322, pis. 1-8.

Forbes, W. T. M. 1942. The Lepidoptera of Barro Colorado Island, Panama. No. 2. Mus. Comp. Zool. (Harvard Univ.) 90(2): 265-406, pis. 9-16.

Haviland, M. D. 1925. Defensive colour and pattern in four caterpillars from British Guiana. Royal Entomol. Soc. London Trans. 73: 575-578.

Heppner, J. B., ed. 1981-. Atlas of Neotropical Lepidoptera: An illustrated catalog of described Neotropical species. Brill, Leiden.

Heppner, J. B. In press. Lepidoptera family classification: A guide to the higher categories, world diversity and literature resources of the butterflies and moths. Flora and Fauna, Gainesville.

Holloway, J. D. 1984. The larger moths of the Gunung Mulu National Park: A preliminary assessment of their distribution, ecology, and potential as environmental indicators. Sarawak Mus. J. 30(51): 149-190.

Janzen, D. H. 1988. Ecological characterization of a Costa Rican dry forest caterpillar fauna. Biotropica 20: 120-135.

Lamas, G., and E. Pérez. 1987. Lepidópteros de importancia médica. Diagnóstico 20: 121-125.

Margheritis, A. E., and H. F. E. Rizzo. 1965. Lepidópteros de interés agrícola. Ed. Sudamericana (Coli. El Mundo Agrie., Ser. Plag. Enferm.), Buenos Aires.

Nentwig, W. 1985. A tropical caterpillar that mimics faeces, leaves and a snake (Lepi doptera; Oxytenidae: Oxytenis naemia). J. Res. Lepidop. 24: 136-141.

Papageorgis, C. 1975. Mimicry in Neotropical butterflies. Amer. Sei. 63: 522-532.

Pliske, T. E. 1975a. Attraction of Lepidoptera to plants containing pyrrolizidine alkaloids. Environ. Entomol. 4: 455-473.

Pliske, T. E. 19756. Pollination of pyrrolizidine alkaloid-containing plants by male Lepidoptera. Environ. Entomol. 4: 474-479.

Quiroz, A. D. 1978. Venoms of Lepidoptera. In S. Bettini, ed., Arthropod venoms. Springer, Berlin. Pp. 555-611.

Raymond, T. 1982. Mariposas de Venezuela. Ed. Corpoven, Caracas.

Rothschild, M. 1972. Colour and poisons in insect protection. New Scient. (11 May): 318-320.

Seitz, A., ed. 1907-1939. The Macrolepi-doptera of the world (Kernen, Stuttgart). Vols. 5-8.

Silberglied, R. E. 1977. Communication in the Lepidoptera. In T. A. Sebeok, ed., How animals communicate. Indiana Univ. Press, Bloomington. Pp. 361-402.

Treat, A. E. 1975. Mites of moths and butterflies. Cornell Univ. Press, Ithaca.

Watson, A., and D. T. Goodger. 1986. Catalogue of the Neotropical tiger-moths. Brit. Mus. Nat. Hist. Occ. Pap. Syst. Entomol. 1: 1-71.

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