The Psychidae (bagworm moths, also simply bagworms or bagmoths) are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of the

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

(

butterflies Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

and

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

s). The bagworm family is fairly small, with about 1,350

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

described. Bagworm species are found globally, with some, such as the snailcase bagworm (''Apterona helicoidella''), in modern times settling continents where they are not native. Another common name for the Psychidae is "case moths", but this is just as well used for the case-bearers (Coleophoridae). The names refer to the habits of

caterpillars Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...

of these two families, which build small protective cases in which they can hide. The bagworms belong to the superfamily

Tineoidea Tineoidea is the ditrysian superfamily of moths that includes clothes moths, bagworms and relatives. There are six families usually included within it, Eriocottidae, Arrhenophanidae, Lypusidae, Acrolophidae, Tineidae and Psychidae, whose r ...

, which is a basal lineage of the

Ditrysia Ditrysia is a clade of lepidopterans that contains both butterflies and a majority of moth species. They are named for the fact that the female has two distinct sexual openings: one for mating, and the other for laying eggs. About 98% of know ...

(as is

Gelechioidea __NOTOC__ Gelechioidea (from the type genus ''Gelechia'', "keeping to the ground") is the Taxonomic rank, superfamily of moths that contains the case-bearers, twirler moths, and relatives, also simply called curved-horn moths or gelechioid moths. ...

, which includes case-bearers). This means that the bagworms and case-bearers are only as closely related to each other as either is to

(Rhopalocera). Most bagworms are inoffensive to humans and inconspicuous; some are occasional nuisance pests. However, a few species can become more serious pests, and have caused significant damage e.g. to wattle (''Acacia mearnsii'') in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and orange (''Citrus × sinensis'') in

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

. If detected early, picking the cases from the trees while in their pupa stage is an effective way to check an infestation; otherwise,

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

s are used. One bagworm species, the

fangalabola Fangalabola (''Deborrea malgassa'') is a species of bagworm moth native to Madagascar. These bagworms are of significance because their pupae are harvested for human consumption in quantity. Biology The length of the larva is 30–40 mm, ...

(''Deborrea malgassa'') of

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

, is in some places encouraged to breed on wattle trees, because its pupae are collected as a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

-rich food.

Description

The

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e of Psychidae construct cases out of silk and environmental materials such as

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

, or

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

materials. These cases are attached to rocks, trees or fences while resting or during their

pupa A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

stage, but are otherwise mobile. The larvae of some species eat

, while others prefer green leaves. In many

, the adult females lack wings and are therefore difficult to identify accurately. Case-bearer cases are usually much smaller, flimsier, and consist mainly of silk, while bagworm "bags" resemble

caddisfly The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

cases in their outward appearance – a mass of (mainly) plant

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

spun together with silk on the inside. Bagworm cases range in size from less than 1 cm to 15 cm among some

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

species. Each species makes a case particular to its species, making the case more useful to identify the species than the creature itself. Cases among the more primitive species are flat. More specialized species exhibit a greater variety of case size, shape, and composition, usually narrowing on both ends. The attachment substance used to affix the bag to host plant, or structure, can be very strong, sometimes requiring a great deal of force to remove. Body markings are rare. Adult females of many bagworm species are larviform, with only

vestigial Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...

wings, legs, and mouthparts. In some species,

parthenogenesis Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertiliz ...

is known. The adult males of most species are strong fliers with well-developed wings and feathery antennae but survive only long enough to reproduce due to underdeveloped mouthparts that prevent them from feeding. Most male bagworm wings have few of the scales characteristic of most moths, instead having a thin covering of hairs. File:Pachythelia villosella.case.jpg, "Bag" of '' Pachythelia villosella'' ( Oiketicinae) File:Grasninella m.JPG, Adult specimen of '' Phalacropterix graslinella'' (Oiketicinae) File:Bagworm Moth larva Negev.JPG, Bagworm larva in the

Negev The Negev ( ; ) or Naqab (), is a desert and semidesert region of southern Israel. The region's largest city and administrative capital is Beersheba (pop. ), in the north. At its southern end is the Gulf of Aqaba and the resort town, resort city ...

(April 2014). Case is made mostly of feathery stork's bill seeds ('' Erodium cicutarium''). File:Family Psychidae444.jpg, Bagworm (possibly '' Hyalarcta huebneri'') extending its forequarters from its case in the act of locomotion.

Ecology

In the larval stage, bagworms extend their head and

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

from their mobile case to devour the leaves of host plants, often leading to the death of their

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

Tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s infested with bagworms exhibit increasingly damaged foliage as the infestation increases until the leaves are stripped bare. Some bagworms are specialized in their host plants ( monophagous), while others can feed on a variety of plant species (polyphagous). A few species also consume small

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s (such as the camphor scale '' Pseudaonidia duplex'', a

scale insect Scale insects are small insects of the Order (biology), order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient g ...

). One bagworm species was found to eat an orb-web of ''Plebs sachalinensis'' (Araneae, Araneidae) entirely. Since bagworm cases are composed of silk and the materials from their habitat, they are naturally camouflaged from predators.

Predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

s include

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s and other

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s. Birds often eat the egg-laden bodies of female bagworms after they have died. Since the eggs are very hard-shelled, they can pass through the bird's

digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller compone ...

unharmed, promoting the spread of the species over wide areas. A bagworm begins to build its case as soon as it hatches. Once the case is built, only adult males ever leave the case, never to return, when they take flight to find a mate. Bagworms add material to the front of the case as they grow, excreting waste materials through the opening in the back of the case. When satiated with leaves, a bagworm

secures its case and pupates. The adult female, which is wingless, either emerges from the case long enough for breeding or remains in the case while the male extends his

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

into the female's case to breed. Females lay their eggs in their case and die. The female evergreen bagworm (''Thyridopteryx ephemeraeformis'') dies without laying eggs, and the larval bagworm offspring emerge from the parent's body. Some bagworm species are

parthenogenetic Parthenogenesis (; from the Greek + ) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means the development of an embryo from an unfertiliz ...

, meaning their eggs develop without male fertilization. Each bagworm generation lives just long enough as adults to mate and reproduce in their annual cycle.

Systematics

Ten subfamilies and about 240 genera are recognized among the bagworms. The subfamilies of Psychidae, with some notable genera and species also listed, are:

Subfamily Epichnopteriginae * '' Acentra'' * '' Bijugis'' * '' Epichnopterix'' ** '' Epichnopterix plumella'' * '' Heliopsychidea'' * '' Mauropterix'' * '' Montanima'' * '' Psychidea'' * '' Psychocentra'' * '' Rebelia'' * '' Reisseronia'' * '' Stichobasis'' ** '' Stichobasis postmeridianus'' * '' Whittleia'' ** '' Whittleia retiella'' Subfamily Naryciinae * '' Dahlica'' Enderlein, 1912 ** '' Dahlica triquetrella'' * '' Eosolenobia'' Filipjev, 1924 * '' Narycia'' * '' Postsolenobia'' Meier, 1958 * '' Siederia'' Subfamily Oiketicinae * '' Apterona'' ** '' Apterona helicoidella'' – (snailcase bagworm) * '' Canephora'' ** '' Canephora hirsuta'' * '' Cryptothelea'' (= ''Platoeceticus'') ** '' Cryptothelea gloverii'' * '' Astala'' * '' Kotochalia'' ** '' Kotochalia junodi'' – (wattle bagworm) * '' Hyalarcta'' * '' Deborrea'' ** '' Deborrea malgassa'' – (fangalabola) * '' Eumeta'' ** '' Eumeta crameri'' – (faggot worm) * '' Megalophanes'' ** '' Megalophanes viciella'' * '' Oiketicus'' * '' Zamopsyche'' * '' Eucoloneura'' * '' Pachythelia'' * '' Phalacropterix'' * '' Ptilocephala'' ** '' Ptilocephala plumifera'' * '' Sterrhopterix'' ** '' Sterrhopterix fusca'' * '' Thyridopteryx'' Subfamily Placodominae * '' Placodoma'' Subfamily Psychinae * '' Liothula'' ** '' Liothula omnivora'' * '' Luffia'' ** '' Luffia ferchaultella'' ** '' Luffia lapidella'' * '' Psyche'' ** '' Psyche casta'' ** '' Psyche crassiorella'' ** '' Psyche rassei'' ** '' Psyche saxicolella'' * '' Prochalia'' Subfamily Taleporiinae * '' Bankesia'' Tutt, 1899 ** '' Bankesia conspurcatella'' * '' Brevantennia'' Sieder, 1953 * '' Cebysa'' ** '' Cebysa leucotelus'' – (Australian bagmoth) * '' Diplodoma'' ** '' Diplodoma adspersella'' * '' Eotaleporia'' Sauter, 1986 * '' Praesolenobia'' Sieder, 1954 * '' Pseudobankesia'' Meier, 1963 * '' Sciopetris'' Meyrick, 1891 * '' Taleporia'' Subfamily Typhoniinae * '' Typhonia'' ** '' Typhonia animosa'' ** '' Typhonia bimaculata'' ''

Incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' * '' Eumasia'' ** '' Eumasia crisostomella'' ** '' Eumasia parietariella'' (Heydenreich, 1851) * '' Iphierga'' ** '' Iphierga chrysophaes'' Turner, 1917 Subfamily Scoriodytinae *'' Scoriodyta'' Meyrick, 1888 ** '' Scoriodyta conisalia'' Meyrick, 1888 Subfamily Metisinae *'' Metisa'' Hampson, 1895 ** '' Metisa canifrons'' Hampson, 1895 Subfamily Pseudarbelinae *'' Pseudarbela'' Sauber, 1902 ** '' Pseudarbela celaena'' (Bethune-Baker, 1904) ** '' Pseudarbela aurea'' (Bethune-Baker, 1904) ** '' Pseudarbela papuana'' Clench, 1959 ** '' Pseudarbela semperi'' Sauber, 1902 *'' Casana'' Walker, 1865 ** '' Casana trochiloides'' Walker, 1865 *'' Linggana'' Roepke, 1957 ** '' Linggana cardinaali'' Roepke, 1957

Applications

The silk of bagworm moth larvae is reportedly "more durable than

spider silk Spider silk is a protein fibre or silk spun by spiders. Spiders use silk to make webs or other structures that function as adhesive traps to catch prey, to entangle and restrain prey before biting, to transmit tactile information, or as nest ...

". Japanese pharmaceutical company Kowa and the National Agriculture and Food Research Organization announced a new textile, Minolon, in 2024, that combined

carbon fibers Carbon fibers American and British English spelling differences, or carbon fibres (alternatively CF, graphite fiber or graphite fibre) are fibers about in diameter and composed mostly of carbon atoms. Carbon fibers have several advantages: ...

with sheets of bagworm silk. The resulting material was claimed to be environmentally friendly, with Kowa planning to sell it to aircraft, automobile, and sporting good manufacturers.

References

External links

Bagworm, Fall Webworm or Eastern Tent Caterpillar?
, August 18, 2001. Sandra Mason, University of Illinois Extension. Accessed May 31, 2010.
Bagworm Control, Photos and Video from University of Nebraska-Lincoln Extension

Bagworm fact sheet from Penn State

Accessed 2002-06-26

{{Authority control Psychidae Moth families