Sphinx Moths

Sphingidae. Spanish and Portuguese: Esfinges. Spanish: Gusanos con cachos, gusanos cornudos (General, larvae). Hummingbird moths, hawkmoths (adults). Hornworms (larvae).

The most characteristic feature of this family of large (WS 5-15 cm) moths is their hovering flight, with elongate wings vibrating at high frequency (25—40 per second), in front of tubular flowers from which they siphon nectar with extra long proboscises. (Wing and proboscis length variations among species are prime indications of adult foraging ecology [Bullock and Pescador 1983].) The action exactly mimics the feeding method of hummingbirds and like that of the latter, is responsible for pollination of many deep-throated Neotropical flowers. Indeed, a symbiotic relationship exists between plant and moth, and some orchids and plants, like the tubular flowered, fragrant Posoqueria longiflora (Rubiaceae), may propagate sexually only with the help of long-tongued sphingids. Because of their strong flight, sphinx moths also may be important longdistance pollinators of lowland forest plants that are found in low densities. Here they most probably fly in the canopy and are maximally abundant during the first few months of the rainy season (Wolda 1980)

Larval behavior, too, is unique. Caterpillars are large (some gigantic; BL up to 15 cm) and, when disturbed, customarily draw their head under their thorax and elevate the latter in an erect posture somewhat resembling the famous Egyptian Sphinx edifice, hence the family name. Most species also possess a spine or thorn on the last abdominal segment, which, although lacking the necessary rigidity to pierce even the most vulnerable tissue, and entirely without venom, probably deters many predators with its menacing appearance. The spine is replaced with an eyespot in some Eumorpha (= Pholus) or a long whiplike tail in mature larvae of certain genera (Isognathus). The size and shape of the horns and the color pattern also may change drastically with development of sphingid larvae.

The family is very well developed in Latin America, with about 308 species (Heppner in press; Schreiber 1978). In spite of the strong dispersal abilities of the adults and the migration tendencies of several, probably most species tend to remain localized in fairly restricted geographic areas (Cary 1951). Several evolutionary dispersal centers have been postulated (Schreiber 1973), but these are of questionable veracity as they are based on biased data. The habits of the adults in some localities (Young 1968; Wolda 1980; Stradling and Legg 1983; Laroca and Mielke 1975) are partially known and but for a few studies (Moss 1912, 1920), the early stages and ecology of most remain a mystery. Flight energetics of forty-four Panamanian species have been studied by Bartholomew and Epting (1975).

References

Bartholomew, G. A., and R. J. Epting. 1975. Rates of post-flight cooling in sphinx moths. in D. M. Gates and R. B. Schmerl, eds., Perspectives of biophysical ecology. Springer, New York. Pp. 405-415. Bullock, S. H., and A. Pescador. 1983. Wing and proboscis dimensions in a sphingid fauna from western Mexico. Biotropica 15: 292-294.

Cary, M. M. 1951. Distribution of Sphingidae (Lepidoptera: Heterocera) in the Antillean-

Caribbean region. Amer. Entomol. Soc. Trans. 77: 63-129. 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. Laroca, S., and O. H. H. Mielke. 1975. Ensaios sobre ecología de comunidade em Sphingidae na Serra do Mar, Paraná, Brasil (Lepidoptera). Rev. Brasil. Biol. 35: 1-19. Moss, A. M. 1912. On the Sphingidae of Peru.

Zool. Soc. London Trans. 20: 73-134. Moss, A. M. 1920. Sphingidae of Para, Brazil.

Nov. Zool. 17: 333-424. Schreiber, H. 1973. Ausbreitungszentrum von Sphingiden (Lepidoptera) in der Neotropis. Amazoniana 4: 273-281. Schreiber, H. 1978. Dispersal centres of Sphingidae (Lepidoptera) in the Neotropical Region. Junk, The Hague. Stradling, D. J., and C.J. Legg. 1983. Observations on the Sphingidae (Lepidoptera) of Trinidad. Bull. Entomol. Res. 73: 201-232. Wolda, H. 1980. Fluctuationes estacionales de insectos en el trópico: Sphingidae. 6th Cong. Soc. Colombiana Entomol. "Socolen" Mem. Pp. 11-58.

Young, A. M. 1968. Notes on a community ecology of adult sphinx moths in Costa Rican lowland tropical rain forest. Caribbean J. Sci. 12: 151-163.

Fig Sphinx

Sphingidae, Macroglossinae, Dilophonotini, Pachylia ficus.

This is a large sphinx moth (WS 12 cm) that exhibits both brown and green color phases (fig. 10.3a). The fore wing is almost uniformly colored save a triangular, light spot at the wing tip and a small circular dark spot midway near the leading edge. The hind wing is a pale shade of the foreground color but transversely twice black banded; it always bears a conspicuous white point in the fringe on the hind margin near the base.

The species' larva also has two basic color phases, either orange-brown or pale green, both variously banded. Usually, there is a yellowish dorsolateral stripe, and the dorsum is a light shade of the same color. There are ill-defined, oblique stripes

Figure 10.3 SPHINX MOTHS (SPHINGIDAE). (a) Fig sphinx (Pachylia ficus), (b) Tobacco Hornworm (Manduca sexta). (c) Tobacco Hornworm, larva, (d) Tobacco Hornworm, pupa, (e) Ashy Sphinx (Erynnis ello). (f) Giant sphinx (Cocytius antaeus).

on the sides. The posterior horn is stubby and slightly curved at the tip. Food plants are all species of fig (Ficus and others in the family Moraceae), and the moth may be very common where the host grows.

Pupation occurs in a considerable cocoon of silk under dead leaves or among grass and stones near the roots of the larval host. The pupal tongue case is fused to the body.

Tobacco Hornworm,

Sphingidae, Sphinginae, Sphingini, Manduca sexta. Spanish: Marandová de las solanáceas (larva). Portuguese: Mandarová do tomate (Brazil, larva). Tomato sphinx, tomato worm (larva).

A major pest of solan aceous crops (tomato, tobacco, potato; Yamamoto and Fraenkel 1960) throughout the region, the larva of this species (fig. 10.3c) is a common sight to the home gardener and commercial farmer alike. It is large when full grown (BL 8 cm) and green, including the head, with diagonal white bars on the sides. It has a well-developed horn and fine, short, stiff hairs all over the body. It forms a pupa with free proboscis case ("jug handled") in a chamber deep in the soil (fig. 10.3d).

The adult is moderately large (WS 12 cm), with gray, bark-patterned fore wings and light gray hind wings crossed by several irregular black bars (fig. 10.3b). A row of six orange-yellow spots line each side of the abdomen.

A common, similar species with its range partly coinciding with the tomato sphinx is the pink-spotted hawkmoth (Agrius [= Herse] cingulatus). The adult is distinguished easily by the pink hind wings and abdominal spots.

Reference

Yamamoto, R. T., and G. S. Fraenkel. 1960. The specificity of the tobacco hornworm, Protoparce sexta, to solanaceous plants. Ento-mol. Soc. Amer. Ann. 53: 503-507.

Ashy Sphingids

Sphingidae, Macroglossinae,

Dilophonotini, Erynnis. Portuguese: Gervao, mandarova da mandioca (Brazil, larva).

These medium-sized (WS 8—9 cm) sphingids are characterized in the adult stage by mottled, ashy gray fore wings and contrasting pink to reddish-yellow black-bordered hind wings (fig. 10.3e). They are widespread wanderers, especially E. ello (Beutel-spacher 1967), which locally is very common around city lights at night and often turns up far from its area of origin.

Mature caterpillars are dichromatic, with green and gray-brown types. In either, the color is frequently broken by a dorsolateral lemon yellow stripe running the entire length of the body. The thorax, behind the flattened head, also may have a rectangular dark brown mark dorsally. The thorax is swollen and the terminal horn vestigial, represented only by a bare nipple. Typically, food plants are toxic wild spurges (Euphorbiaceae: Sebastiana, Cnido-scolus), dogbanes (Apocynaceae), and milkweeds (Asclepiadaceae: Sarcostemma, Phili-bertia), including ornamentals such as poin-settia and allamanda and crops such as papaya, guayaba, and manioc on which they are considered minor pests (Bellotti and Arias 1978). Larvae of E. ello, utilizing Cnidoscolus as a host (mala mujer), avoid the plant's urticating hairs and latex defenses by first grazing the former from the petiole and gnawing the petiole, effectively stopping the flow of the latex to the leaf, on which it then feeds (Dillon et al. 1983).

Pupation occurs in a stout web spun among leaves on the surface of the ground. The pupa itself is shining black, sometimes splashed with orange; its proboscis is fused to the ventral surface.

References

Bellotti, A., and B. Arias. 1978. Biology, ecology and biological control of the cassava horn worn (Erynnis ello). In Cassava Protection Workshop, C1AT (Cali, Colombia). Pp. 227-232.

Beutelspachf.r, C. 1967. Estudio morfológico de Erynnis ello (L.), 1758 (Lepidoptera: Sphingidae). Inst. Biol., Univ. Nac. Autón. México, Ser. Zool., Ann. 1: 59-74. Dillon, P. M„ S. Lowrie, and D. McKey. 1983. Disarming the "Evil Woman": Petiole constriction by a sphingid larvae circumvents mechanical defenses of its host plant, Cnidoscolus urens (Euphorbiaceae). Biotropica 15: 112-116.

Giant Sphinx

Sphingidae, Sphinginae, Sphingini,

Cocytius antaeus.

One of the largest sphingids in the world, this has a wingspan of 15 to 16 centimeters (fig. 10.3f). It also has one of the longest tongues of any sphinx in the world, fully 11 centimeters when extended, which is apparently adapted for tapping nectar from very deep-throated flowers. The slightly larger, related Neotropical species Amphimoeca walkeri actually holds the world's record for the longest tongue; it measures over 28 centimeters from base to tip (Amsel 1938).

This species' fore wings are patterned like tree bark with gray and black lines on a dark brownish background; the hind wings are translucent in the center, so that the veins are visible, orange basally and black bordered. Three yellow spots mark each side of the abdomen at its base.

Its larva is immense, reaching a body length of 14 centimeters or more when full grown, and generally uniform light greenish with a mauve line edged with white down the back. It also has faint, oblique lateral lines, the most posterior of which, extending from the base of the caudal horn, is conspicuous, cream-colored, and much larger than the others. The skin is covered with short, reddish hairs and has a well-developed, rough-surfaced pink and gray horn. It feeds on Annonaceae, including custard apple (Annona glabra).

The enormous (8 cm long) pupa has a short free tongue case and develops in an earthen cavity near tree roots.

Reference

Amsel, H. G. 1938. Die Schwärmer mit dem längsten Rüssel. Entomol. Rundsch. (Stuttgart) 55(15): 165-167.

Frangipani Sphinx

Sphingidae, Macroglossinae,

Dilophonotini, Pseudosphinx tetrio.

The gaudy, large (BL up to 15 cm, weight 15 g) caterpillar of this species (fig. 10.4b), with its clown pattern of yellow bands on a black background and bright red head, often attracts attention, the more so when it groups with others of its kind and forms long processions along tree branches and trunks. IL is recognized also by orange-vermilion tail flaps and a prothoracic shield plus a long, whiplike, black tail. These colors are thought to advertise an objection

Figure 10.4 SPHINX MOTHS (SPHINGIDAE). (a) Frangipani sphinx (Pseudosphinx tetrio). (b) Frangipani sphinx, larva, (c) Viper worm (Hemeroplanes ornatus), adult, (d) Viper worm, larva (resting position), (e) Viper worm, larva (threat posture), (f) Harlequin sphinx (Eumorpha fasciata).

able taste or disposition to predators; if molested, it jerks the forepart of its body violently back and forth, bites, and rubs the substrate with the side and back of the head. An alternate theory justifies the pattern as mimicking that of a coral snake (Janzen 1980). It is well known and feeds at night on popular ornamental garden plants, including frangipani (Plumería rubra) and alla-manda (Allamanda). Its natural hosts are poorly known; "caucho de monte," a wild rubber, is cited as one.

The adult is large (WS 10—15 cm), with fore wings marked with shades of gray in a bark pattern (fig. 10.4a). The hind wings are uniformly dark gray, and the abdomen has wide dark gray bands interrupted by pale gray rings. The streamlined, elongate pupa, with appressed proboscis case, lies in the soil near the surface, covered by sparse silk threads.

The species' general biology has been reviewed by Janzen (1983) and Santiago-Blay (1985).

References

Janzen, D. H. 1980. Two potential coral snake mimics in a tropical deciduous forest. Bio-tropica 12: 77-78. Janzen, D. H. 1983. Pseudosphinx tetrio (oruga falso-coral, frangipani sphinx). In D. H. Janzen, ed., Costa Rican natural history. Univ. Chicago Press, Chicago. Pp. 764-765. Santiago-Blay, J. A. 1985. Notes on Pseudo-sphinx tetrio (L.) (Sphingidae) in Puerto Rico. J. Lepidop. Soc. 39: 208-214.

Viper Worms

Sphingidae, Macroglossinae,

Dilophonotini, Hemeroplanes.

The behavior and appearance of several Neotropical sphinx larvae are incredibly similar to those of small arboreal snakes. These all belong to the genus Hemeroplanes, but the different species appear to mimic different snakes. The best known is H. ornatus, found widely through the wet forests of Amazonia and northward to Trinidad and the Caribbean borderlands (Hogue 1982). The larva (Moss 1920) is large at maturity (BL 10 cm), gray-green ventrally and pale mottled dorsally (fig. 10.4d). This is the reverse of normal coun-tershading, an arrangement in keeping with the larva's habit of walking upside down on horizontal twigs. The relationship, however, is correct for a snake that normally travels upright on such branches.

When disturbed by a potential predator, the larva reacts violently (fig. 10.4e), arching the anterior part of its body toward the attacker (pi. 3e). At the same time, the thorax is inflated, assuming a triangular shape like a viper's head. Large, dark circular spots on either side appear as eyes, and a row of square pale spots on either side mimic perfectly the scale rows along the border of the mouth of the serpent. The effect may be enhanced by a swaying motion, like that of a snake on alert. The sham is so near perfect that even entomolo gists may be reluctant to pick up specimens without studying them closely first.

The models for this extreme case of Batesian mimicry are not known but are speculated to be small species of arboreal Bothrops, of which there are several in coincident geographic areas. A likely candidate for H. ornatus is B. bilineatus, which lives on shrubs and saplings such as the moth chooses as hosts for its larvae. Known food plant species are all found in the dogbane family (Apocynaceae) and include Zschokkea, Echites, Amblyanthera versicolor, and Lacmellea aculeata.

The adults (fig. 10.4c) are medium-sized moths (WS 7-8 cm), with jagged wing margins; their color is dark velvety brown except for conspicuous, forked silver streaks in the middle of the fore wings.

The caterpillars of a few species of Eu-morpha, most notably, E. labruscae, mimic the snake form similarly, although less convincingly. A "blinking" eye (maroon spot with a black "pupil" that palpitates) replacing the anal horn in the mature stage, however, is an innovative feature of the deception (Curio 1965). These larvae are found on Ampelopsis (Vitaceae) in Amazonia.

References

Curio, E. 1965. Die Schlangenmimikry einer Südamerikanischen Schwärmerraupe. Natur und Museum 95: 207-211. Hogue, C. L. 1982. La viboruga: El extraño insecto que se parece a una víbora. Geo-mundo 6: 308-309. Moss, A. M. 1920. Sphingidae of Para, Brazil. Nov. Zool. 17: 333-424.

Harlequin Sphingids

Sphingidae, Macroglossinae, Philampelini, Eumorpha (= Pholus). Portuguese: Esfinges palha^äo (Brazil).

The several species in this widespread, entirely Neotropical genus are noteworthy for their large size (WS 13-14 cm). The fore wing pattern is a harlequin patchwork of light and dark browns (some green, as in

E. fasciata, fig. 10.4f), a prominent and consistent mark being a dark, rectangular bar on the posterior margin about midway. The hind wings are sometimes pinkish, yellowish, or infused with blue. There are also identifying dark triangles on either side of the back of the thorax.

The caterpillars are stout bodied, and the horn is often replaced by a button after the last molt. The third thoracic segment is very large, and the head and first two thoracic segments are retracted into it when the larva is disturbed. Food plants are members of the grape (Vitaceae), dogbane (Apocynaceae), and evening primrose (Onagraceae) families. Pupation occurs in a subterranean cell.

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