Hydroptilidae is a large family of caddisflies (Trichoptera) with a worldwide distribution

Cosmopolitan distribution

In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...

. They are commonly known as microcaddisflies or purse-case caddisflies, in reference to two characteristic traits of this family: Hydroptilidae are much smaller than other caddisflies, rarely exceeding 5 millimetre (0.196850393700787 in) in length. Their larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e do not build a protective case until the final instar

Instar

An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...

 of their growth. At that time however, they build a typically purse

Purse

A purse is a small bag that may refer to:* Coin purse, in British English* Handbag, in American English* Money bag* WalletPurse may also refer to:...

-shaped case, either portable or stuck to the substrate

Substrate (biology)

In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...

, in which the larva finishes growth and pupa

Pupa

A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...

tes.

Systematics and taxonomy

Their systematic

Systematics

Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...

 placement among the caddisflies is still disputed. They are traditionally placed in the suborder "Spicipalpia

Spicipalpia

Spicipalpia is a suborder of Trichoptera, the caddisflies. The four families included in this suborder all have the character of pointed maxillary palps in the adults...

", which do not seem to be a natural monophyletic group but rather an evolutionary grade

Evolutionary grade

In alpha taxonomy, a grade refers to a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit.-Definition:...

 of moderately-advanced caddisflies. Some authors downrank the "Spicipalpia" to a superfamily

Taxonomic rank

In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...

 of the more basal Annulipalpia

Annulipalpia

Annulipalpia is a suborder of Trichoptera. The name of the suborder refers to the flexible terminal segment of the adult maxillary palps, which often has many tiny rings. The larvae construct fixed retreats in freshwater aquatic environments. Most of the families are unique in spinning silken nets...

 and call them Rhyacophiloidea (which otherwise refers to

Rhyacophiloidea

Rhyacophiloideais a superfamily in the insect order of Trichoptera....

 a subfamily of suborder Spicipalpia), but recent studies generally rejected this view.

More often, the Hydroptilidae are placed in a monotypic

Monotypic

In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 superfamily Hydroptiloidea, either in the "Spicipalpia" or – probably more appropriately considering the present state of caddisfly phylogeny – incertae sedis

Incertae sedis

, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...

in the Trichoptera. It may be that the Glossosomatoidea

Glossosomatoidea

Glossosomatoidea is a superfamily of the class Insecta and order Trichoptera....

 are particularly closely related to the Hydroptilidae; together they might even be closer to the most advanced caddisflies (the tube case caddisflies, Integripalpia) than any other living caddisfly. But this view is almost as disputed as including the "Spicipalpia" in the Annulipalpia. In any case, were Glossosomatoidea and Hydroptiloidea to be merged into a single superfamily, the older name Hydroptiloidea would apply for the combined group.

The peculiarly apomorphic genera

Genera

Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

 Palaeagapetus and Ptilocolepus have been separated as subfamily Ptilocolepinae, while all other genera form the Hydroptilinae with its multiple tribe

Tribe (biology)

In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...

s. It is far from certain that the Ptilocolepinae are the living fossil

Living fossil

Living fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...

s such an arrangement would imply them to be.

Genera

Around 70 genera with at least 1,700 species has been described from this family:

Hydroptilinae J. F. Stephens, 1836

• Acanthotrichia A. Wells, 1982
• Acritoptila A. Wells, 1982
• Agraylea J. Curtis, 1834
• Allotrichia R. McLachlan, 1880
• Austratrichia A. Wells, 1982
• Cyclopsiella J. Kjaerandsen, 1997
• Dhatrichia M. E. Mosely, 1948
• Hellyethira A. Neboiss, 1977
• Hydroptila
  Hydroptila
  Hydroptila is a very large genus of microcaddisflies with a worldwide distribution.-Species:*Hydroptila abantica*Hydroptila abbotti*Hydroptila acadia*Hydroptila acinacis*Hydroptila acrodonta*Hydroptila acuminata...
  
  J. W. Dalman, 1819
• Hydroptilina A. V. Martynov, 1934
• Jabitrichia A. Wells, 1990
• Microptila F. Ris, 1897
• Missitrichia A. Wells, 1991
• Mulgravia A. Wells, 1982
• Oxyethira A. E. Eaton, 1873
• Paroxyethira M. E. Mosely, 1924
• Paucicalcaria M. L. Mathis & D. E. Bowles, 1989
• Tangatrichia A. Wells & T. Andersen, 1995
• Tricholeiochiton G. S. Kloet & W. D. Hincks, 1944
• Ugandatrichia M. E. Mosely, 1939
• Vietrichia J. Olah, 1989
• Wlitrichia J. Kjaerandsen, 1997
• Xuthotrichia M. E. Mosely, 1934

Leucotrichiinae O. S. Flint, 1970

• Abtrichia M. E. Mosely, 1939
• Acostatrichia M. E. Mosely, 1939
• Alisotrichia O. S. Flint, 1964
• Anchitrichia O. S. Flint, 1970
• Ascotrichia O. S. Flint, 1983
• Betrichia M. E. Mosely, 1939
• Celaenotrichia M. E. Mosely, 1934
• Cerasmatrichia O. S. Flint, S. C. Harris & L. Botosaneanu, 1994
• Ceratotrichia O. S. Flint, 1992
• Costatrichia M. E. Mosely, 1937
• Eutonella F. Mueller, 1921
• Leucotrichia M. E. Mosely, 1934
• Mejicanotrichia S. C. Harris & R. W. Holzenthal, 1997
• Peltopsyche F. Mueller, 1879
• Scelobotrichia S. C. Harris & J. Bueno-Soria, 1993
• Zumatrichia M. E. Mosely, 1937

Neotrichiinae H. H. Ross, 1956

• Kumanskiella S. C. Harris & O. S. Flint, 1992
• Mayatrichia M. E. Mosely, 1937
• Neotrichia K. J. Morton, 1905
• Taraxitrichia O. S. Flint & S. C. Harris, 1991

Ochrotrichiinae J. E. Marshall, 1979

• Metrichia H. H. Ross, 1938
• Ochrotrichia
  Ochrotrichia
  Ochrotrichia is a large genus of microcaddisflies. All are Nearctic or Neotropical in distribution apart from Ochrotrichia verbekei, recorded from the Democratic Republic of the Congo.-Species:*Ochrotrichia affinis*Ochrotrichia alargada...
  
  M. E. Mosely, 1934
• Rhyacopsyche F. Mueller, 1879

Orthotrichiinae A. Nielsen, 1948

• Ithytrichia A. E. Eaton, 1873
• Nothotrichia O. S. Flint, 1967
• Orthotrichia A. E. Eaton, 1873

Stactobiinae L. Botosaneanu, 1956

• Bredinia O. S. Flint, 1968
• Byrsopteryx O. S. Flint, 1981
• Catoxyethira G. Ulmer, 1912
• Chrysotrichia F. Schmid, 1958
• Flintiella E. B. Angrisano, 1995
• Niuginitrichia A. Wells, 1990
• Orinocotrichia S. C. Harris, O. S. Flint & R. W. Holzenthal, 2002
• Parastactobia F. Schmid, 1958
• Plethus H. A. Hagen, 1887
• Scelotrichia G. Ulmer, 1951
• Stactobia R. McLachlan, 1880
• Stactobiella A. V. Martynov, 1924
• Tizatetrichia S. C. Harris, O. S. Flint & R. W. Holzenthal, 2002

incertae sedis

Incertae sedis

, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...

• †Burminoptila L. Botosaneanu, 1981
• Caledonotrichia J. L. Sykora, 1967
• Dibusa H. H. Ross, 1939
• Dicaminus F. Mueller, 1879
• †Electrotrichia G. Ulmer, 1912
• Macrostactobia F. Schmid, 1958
• Maydenoptila A. Neboiss, 1977
• †Novajerseya L. Botosaneanu, R. O. Johnson & P. R. Dillon, 1998
• Orphninotrichia M. E. Mosely, 1934

External links

• Trichoptera World Checklist