The Limacodidae or Eucleidae are a family of

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

s in the superfamily Zygaenoidea or the Cossoidea;Scoble, M.J. (1992). ''The Lepidoptera: Form, Function and Diversity.'' Oxford University Press. the placement is in dispute. They are often called slug moths because their caterpillars bear a distinct resemblance to slugs. They are also called cup moths because of the shape of their cocoons. The larvae are often liberally covered in protective stinging hairs, and are mostly

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

, but occur worldwide, with about 1800 described species and probably many more as yet undescribed species.

Description

Moths

They are small, hairy moths, with reduced or absent mouthparts and fringed wings. They often perch with their

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...

s sticking out at 90° from their thoraces and wings. North American moths are mostly cryptic browns, sometimes marked with white or green, but the hag moth mimics bees.Wagner, D.L. (2005). ''Caterpillars of Eastern North America.'' Princeton University Press.

Pupae

The final

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

constructs a silk cocoon and hardens it with calcium oxalate excreted from its Malpighian tubules. Cocoons have a circular escape hatch, formed from a line of weakness in the silk matrix. It is forced open just prior to emergence of the adult.Epstein, M.E. (1996). "Revision and phylogeny of the limacodid-group families, with evolutionary studies on slug caterpillars (Lepidoptera: Zygaenoidea)." ''Smithsonian Contributions to Zoology.'' No. 582. ISSN 0081-0282

Caterpillars

The larvae are typically very flattened, and instead of

proleg A proleg is a small, fleshy, stub structure found on the ventral surface of the abdomen of most larval forms of insects of the order Lepidoptera, though they can also be found on other larval insects such as sawflies and a few other types of in ...

s, they have suckers. The thoracic legs are reduced, but always present, and they move by rolling waves rather than walking with individual prolegs. They even use a lubricant, a kind of liquefied

silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the ...

, to move. Larvae might be confused with the similarly flattened larvae of lycaenid butterflies, but those caterpillars have prolegs, are always longer than they are wide, and are always densely covered in short or long

setae In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

(hair-like bristles). The head is extended during feeding in the lycaenids, but remains covered in the Limacodidae. Many limacodid larvae are green and fairly smooth (e.g. yellow-shouldered slug), but others have tubercles with

urticating hair Urticating hairs or urticating bristles are one of the primary defense mechanisms used by numerous plants, almost all New World tarantulas, and various lepidopteran caterpillars. ''Urtica'' is Latin for "nettle" (stinging nettles are in the genu ...

s and may have bright warning colours. The sting can be quite potent,Marshall, S.A. (2006). ''Insects: Their natural history and diversity.'' Firefly Books. causing severe pain. The larval head is concealed under folds. First-

s skeletonise the leaf (avoiding small veins and eating mostly one surface), but later instars eat the whole leaf, usually from the underside. Many species seem to feed on several genera of host plants. Limacodidae larvae in temperate forests of eastern North America prefer

glabrous Glabrousness (from the Latin '' glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

leaves, presumably because the

trichomes Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

of pubescent leaves interfere with their movement.Lill, J.T., Marquis, R.J., Forkner, R.E., Le Corff, J., Holmberg, N., & Barber, N.A. (2006). "Leaf pubescent affects distribution and abundance of generalist slug caterpillars (Lepidoptera: Limacodidae)." ''Environmental Entomology'' 35(3): 797-806. ISSN 0046-225X Image:PhobUnderside.JPG, Underside of a monkey slug, showing the slimy pad in place of prolegs Image:Lithacodes.JPG, Larva of the yellow-shouldered slug, showing typical body shape Image:Cup moth caterpillar.jpg, Limacodid larva, showing bright colours and presumably stinging setae Image:Saddleback (Sibine stimulea).jpg, ''Sibine stimulea'' ( saddleback caterpillar) larva File:Parasa pastoralis caterpillar.jpg, Larva of '' Parasa pastoralis'' Image:Stinging_Rose_caterpillars,_Megan_McCarty65.jpg, Stinging rose caterpillars ('' Parasa indetermina'') Image:Richters wurm.JPG, Limacodid larva File:Limacodidae (Slug moths) caterpillar W IMG 2795.jpg, Limacodid (slug moth) caterpillar Slug moth caterpillar (Limacodidae sp.).jpg, Slug moth caterpillar,

Sabah Sabah () is a state of Malaysia located in northern Borneo, in the region of East Malaysia. Sabah borders the Malaysian state of Sarawak to the southwest and the North Kalimantan province of Indonesia to the south. The Federal Territory o ...

, Borneo

Eggs

Eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

are flattened and thin. They are highly transparent and the larva can be seen developing inside. They may be laid singly or in clusters on leaves.

Ecological importance

Limacodidae (e.g. '' Latoia viridissima'', '' Parasa lepida'', '' Penthocrates meyrick'', '' Aarodia nana'') have caused serious

defoliation A defoliant is any herbicidal chemical sprayed or dusted on plants to cause their leaves to fall off. Defoliants are widely used for the selective removal of weeds in managing croplands and lawns. Worldwide use of defoliants, along with the ...

palm Palm most commonly refers to: * Palm of the hand, the central region of the front of the hand * Palm plants, of family Arecaceae **List of Arecaceae genera * Several other plants known as "palm" Palm or Palms may also refer to: Music * Palm (ba ...

Notable species

* Hag moth or monkey slug ('' Phobetron pithecium'') * Ochre-winged hag moth or yellow-shouldered slug ('' Lithacodes fasciola'') * Spiny oak slug ('' Euclea delphinii'') * Crowned slug (''

Isa textula ''Isa textula'', the crowned slug moth or skiff moth is a moth of the family Limacodidae. It is found in North America from Minnesota, southern Ontario and Massachusetts to Florida, Texas, and Mississippi. The larvae feed on the leaves of variou ...

'') * Skiff moth (''

Prolimacodes badia ''Prolimacodes badia'', the skiff moth, is a moth of the family Limacodidae. It is found in North America from New Hampshire to Florida, west to southern Ontario, Missouri, Arkansas and Mississippi. The wingspan is 24–35 mm. Adults ar ...

'') * Nettle caterpillar ('' Latoia viridissima'') * Saddleback caterpillar ('' Acharia stimulea'')

References

External links

Brisbane Limacodids, with photo of cocoon.

Moths of Borneo {{Authority control Limacodidae, Moth families