Tiger Moths

Arctiidae, Arctiinae. Spanish: Gatas peludas (larvae). Portuguese: Largatas cabeludas (Brazil, larvae).

Certainly these are the most flamboyantly colored and varied single family of moths in the Neotropics. Unbelievably garish and gorgeous, polychromatic combinations of florid hues are juxtaposed in kaleidoscopic arrays on the fore wings of many species (seldom also on the hind wings, which are more usually drably monochromatic). These color arrangements have protective functions, either as camouflage or warnings of distastefulness. In the former category are mimics of lichens (Hypercompe = Ecpantheria, fig. 10.5g), dead leaves (Bertholdia), or bark (Leu-canopsis = Halysidota); there are also tessellated (Idalus, fig. 10.5f; Eucereon) or disruptive patterns (Viviennea, fig. 10.5e; Paranerita).

Wing waving displays, cataleptic seizures, extrusions of hair tufts, reflexive frothing, and bleeding of yellow body fluid from the neck are direct defenses that they advertise by bright (aposematic) colors. Many species even emit high-frequency sounds by distorting ridges on the thoracic wall when roughly handled (Blest et al. 1963), and all such moths are summarily rejected by monkeys, bats (Dunning 1968), birds, toads, and other potential predators (Blest 1964).

Few life histories of the Neotropical species are known. The larvae are all densely clothed with nonurticating hairs that arise from small wartlike swellings on the cuticle. These hairs are usually stiff and dark but may be soft, tufted, and of other colors, often white or red and even bicolored to produce a banded pattern (fig. 10.5d, pi. 2e). The larvae feed on varied plant types, perhaps favoring Compositae, and many species are polyphagous. Some prefer plants containing pyrrolizidine alkaloids (such as Crotalaria, Heliotropium, and Sene-

cio) or other toxic compounds (Euphorbia, So-lanum) in European and presumably also the Neotropical species (Rothschild et al. 1979). Pupae are hidden in a loose silken cocoon into which the larval hairs are usually incorporated.

According to a recent count (Watson and Goodger 1986), there are 1,939 described Latin American species of tiger moths classed in 174 genera, but there are many more species to be discovered. They are highly diverse in form (Watson 1971, 1973) and pattern, making them somewhat difficult to recognize as a group, but nearly all have a tymbal (sound-producing organ). The diurnal mimetic species can be placed in their proper subfamily by the tymbal and vein pattern in the hind wing (see mimetic moths, above).

A few tiger moths are apparently specific Batesian mimetics of other distasteful insects. With wings at rest, Opharus bimacu-latus closely resembles the luminescent headlight beetles (Pyrophorus). Both are elongate and generally dark brown; the twin glowing spots on the beetle are simulated by large, circular cream spots in the thorax of the moth. Other species are themselves distasteful and clearly members of Miillerian mimicry complexes. An example is Cratoplastis, with species (especially diluta) that resemble the cockroach Achro-blatta luteola and members of the firefly beetle genus Cratomorphus (orig. obs.).

References

Blest, A. D. 1964. Protective display and sound production in some New World arctiid and ctenuchid moths. Zoologica 49: 161 — 181. Blest, A. D., T. S. Collett, and J. D. Pye. 1963. The generation of ultrasonic signals by a New World arctiid moth. Royal Soc. Proc. B 158: 196-207. Dunning, D. C. 1968. Warning sounds of moths. Zeit. Tierpsychol. 25: 129-138. Rothschild, M., R. T. Aplin, P. A. Cockrum, J. A. Edgar, P. Fairweather, and R. Lees. 1979. Pyrrolizidine alkaloids in arctiid moths (Lep.) with a discussion on host plant relationships and the role of these secondary plant substances in the Arctiidae. Biol. J. Linnean Soc. (London) 12: 305-326.

Watson, A. 1971. An illustrated catalog of the Neotropic Arctiinae types in the United States National Museum (Lepidoptera: Arctiidae). pt. I. Smithsonian Contrib. Zool. 50: 1—361.

Watson, A. 1973. An illustrated catalog of the Neotropic Arctiinae types in the United States National Museum (Lepidoptera; Arctiidae). Pt. II. Smithsonian Contrib. Zool. 50: 1-160.

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

Wasp Moths

Arctiidae, Ctenuchinae (= Ctenuchidae, Amatidae, Euchromiidae, Syntomidae).

This is a special group of tiger moths that often display gaudy combinations of bright, often metallic, colors on their anterior (sometimes posterior also) wings. The fore wings generally are more elongate, and they often have tufted or paddlelike expansions of scales on the hind legs which apparently imitate the pendant hind legs of real wasps in flight. They are mostly diurnal. The vein branching pattern in the hind wing also is slightly different (see mimetic moths, above). Like other tiger moths, wasp moths utilize several elaborate protective devices, such as playing dead, sound production, bad taste, emission of foul substances, and color and behavioral displays (Blest 1964). A few species possess long scaled "pigtails," structures of unknown function, trailing from the apex of the abdomen.

Many wasp moths are active during the day and mimic wasps, bees, and beetles, including some truly remarkable imitators of vespid wasps in the genus Pseudosphex. They have clear, plaited wings that they hold erect and are narrow waisted and aggressive, all features precisely copying vespid structure and behavior (Beebe and Kennedy 1957: 148-150). Macrocneme (fig. 10.6b), Pseudopompilia, and other species have wings with solid shades very much like those of pepsis wasps, which they resemble also in general form. Others, for example, Correbidia assimilis and Correbia, are variously black or dark blue and yellow banded or spotted in patterns copying those of net-winged beetles (Lycidae), which are protected by their yellow, oily, repugnant body fluids. Slow, fluttering flight in all of these enhances their resemblance to their models.

Adults of many species of wasp moths are attracted to Heliotropium, Senecio, and Vernonia, from which it is presumed they extract compounds important in their lives (Moss 1947), but no details are available yet concerning what these substances are or the ways in which they are used.

Common nocturnal species comprise the large genus Eucereon (Arctiinae), whose members are recognized by their tessel

Flflure 10.6 MOTHS, (a) Smoky moth (Harrisina tergina, Zygaenidae). (b) Wasp moth (Macrocneme chrysitis, Arctiidae). (c) Flag moth (Dysschema leucophaea, Arctiidae), larvae, (d) Dioptid moth (Dioptis restricta, Dioptidae). (e) Flag moth (Daritis howardi, Arctiidae), male, (f) Flag moth (Daritis howardi), female, (g) Giant day-flying moth (Castnia licoides, Castniidae). (h) Giant day-lying moth, larva.

lated, cryptic fore wings and red or blue marked abdomens. They can produce sound when disturbed, like some tiger moths (Blest 1964).

The larvae, very few of which are known (Beebe 1953), are similar to those of tiger moths but somewhat less hairy and with softer, even silky setae that often arise in tufts and may be extra long, especially at the extremities of the body. The portion of the integument that is exposed is often marked with colored spots or lines or both, unlike the neutral skin of the tiger moth larvae. Known food plants are chiefly monocots, including common types such as grasses and Carina, but some dicots are eaten as well (Moss 1947). One pest species that attacks bananas is Antichloris viridis (Field 1975). Pupation takes place in a loose, fragile cocoon in litter or is hidden under loose bark on tree trunks.

The subfamily contains over 2,100 species on the Neotropics, its area of maximum diversity.

References

Beebe, W. 1953. A contribution to the life history of the euchromid moth, Aethria carnicauda Butler. Zoologica 38: 155-160. Beebe, W., and R. Kennedy. 1957. Habits, palatability and mimicry in thirteen ctenu-chid moth species from Trinidad, B.W.I. Zoologica 42: 147-158. Blest, A. D. 1964. Protective display and sound production in some New World arctiid and ctenuchid moths. Zoologica 49: 161-181. Field, W. D. 1975. Ctenuchid moths of Ceramidia Butler, Ceramidiodes Hampson, and the caca species group of Antichloris Hiibner. Smithsonian Contrib. Zool. 198: 1—45. Moss, A. M. 1947. Notes on the Syntomidae of Para, with special reference to wasp mimicry and fedegoso, Heliotropiurn indicum (Bora-ginaceae), as an attractant. The Entomologist 80: 30-35.

Flag Moths

Arctiidae, Pericopinae.

Pericopines are medium-sized to large (WS 4-10 cm). All are diurnal and display mimetic wing patterns. They are named "flag moths" here because, like banners, their generally broad wings display sharply defined bands or fields of contrasting bright colors. Anatomical features that distinguish them are unusually large, hoodlike flaps (tympanic hoods) arising dorsally at the base of the abdomen and extending over the rear portion of the thorax, in addition to the hind wing vein branches discussed above (see mimetic moths).

Adults are well protected by noxious body fluids; they can also emit a yellow spume from the neck, making them unpleasant even to handle. Before these lines of defense take effect, they may be mauled by a predator, but their bodies are rather rubbery and can withstand considerable trauma without much damage. Flag moth color patterns are often sexually dimorphic (as in Daritis howardi = thetis, fig. 10.6e, f) and probably mimetic, the two sexes possibly to different models. Male Dysschema jansoni are presumed mimics of aposematic Parides swallowtail butterflies, the females of ithomiines (Aiello and Brown 1988).

The immatures and biology of few flag moths are known. The larvae resemble those of tiger moths, with abundant hair, and they are brightly colored and gregarious (fig. 10.6c). They feed on various Compositae, some of which contain toxic or repugnant chemicals (Senecio, Vernonia) that are probably sequestered and responsible for the adult's unpalatability. When molested, they have been observed to thrash about and exude droplets of fluid (Young 1981). The pupae are metallic colored and placed in a loose, baggy cocoon.

There are 369 species in the Neotropical region (Watson and Goodger 1986).

References

Aiello, A., and K. S. Brown, Jr. 1988. Mimicry by illusion in a sexually dimorphic, day-flying moth, Dysschema jansoni (Lepidoptera: Arctiidae: Pericopinae). J. Res. Lepidop. 26: 173-176.

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

Young, A. M. 1981. Notes on the moth Pericopis leucophaea Walker (Lepidoptera: Pericopidae) as a defoliator of the tree Vernonia patens H.B.K. (Compositae) in northeastern Costa Rica. New York Entomol. Soc. J. 89: 204-213.

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