Insect of the week – number 18

Diptera: Psychodidae: Telmatoscopus Clogmia albipunctata (Williston, 1983)

Thursday morning I awoke with the plan to do a write up on green pea aphid, Acyrthosiphon pisum, for the NC insect of the week. I had been waging a personal war against the aphids which had been attacking my garden peas, tomatoes and beans for weeks. However, as I slowly meandered sleepy-eyed into the kitchen desperate for coffee, I noticed a moth fly (Psychodidae) perched upon my kitchen counter. Dedicated to my coffee mission, I neglected to collect the beautiful hairy fly that sat so peacefully near the sink. When I arrived on campus, I thought I might have a look in the collection to see if I could pinpoint to which species, or at least genus, to which my hairy friend might belong.

Psychodids can be identified to genus based on characters such as the presence of an eye bridge, the shape of the flagellomeres and mouth parts, and wing venation. Of course, my 60 second eyeball examination of this fly and lack of entomological skills first thing in the morning was not going to give me enough clues to positively identify this fly to species. However, there was a series of specimens in the NCSU collection that were identified as Telmatoscopus albipunctatus. These flies bore striking resemblance to the fly I observed earlier that morning. Interestingly, almost of the collecting localities were in Raleigh or nearby counties from inside of houses. I very unscientifically decided that this was the fly I saw, and decided this was going to be the insect of the week.

Photo Credit: leandrocarvalhobr, from Flickr.

T. albipunctatus is a species in the subfamily Psychodinae, which are commonly referred to as sewer flies, drain flies, filter flies, bathroom flies, or moscas de baño. These flies are readily identified by their hairy bodies and hairy wings with a characteristic frond shape and long, primarily straight veins to the tip of the wings. Psychodinae includes 10 valid genera (according to ITIS). There is some confusion, at least on my part, over the valid genus and species name. There are many publications that list the bionominal as Clogmia albipunctata (Williston, 1893) (=Telmatoscopus). However, Telmatoscopus is listed as the current generic assignment in the ITIS database (I would be happy to hear comments from the dipterists). A junior synonym the original name given to this species by Williston in 1983, Psychoda albipunctata.

The larvae of this group of flies are aquatic to semi-aquatic, have sclerotized plates on the dorsal side of the body and a characteristic siphon (see photo below) for breathing in low oxygen environments, such as mud. Larvae are often found in decomposing vegetation and therefore are often associated with the sludge found in sink drains, where food particles have collected and decayed. Thus, the adults are found in bathrooms, showers, and kitchens. A quick search on the internet will reveal many people trying to destroy these adorable little flies, as they can become quite the household nuisance. Recently, T. albipunctatus was reported in the gastro-intestinal tract of a Taiwanese man, suggesting these flies might be more than a nuisance if accidently ingested. Although GBIF only lists this species from Japan, they are clearly in Raleigh and other Nearctic locations, and certainly have a much larger distribution.

Photo Credit and Copyright: Ashley Bradford.

In the NCSU Insect collection, the oldest specimen dates back to August 2, 1926, and was collected here in Raleigh, NC (see below). I believe the collector’s name was J.W. Dexmark, but the handwritten name is difficult to make out. There is a large series of specimens collected by C.S. Brimley, who worked for the North Carolina Department of Agriculture in the 1920’s and 1930’s. Several labels actually have Z.P. Metcalf’s typed name on the label as the collector, with the initials of Brimley (CSB) handwritten overtop. The most recent specimen was collected in 1974 on July 1st by H. Blackmore in Dunn, NC. The habitat information reads “inside house”.

Oldest specimen in the NCSU Insect Collection.

Find out more

Telmatoscopus albipunctatus (Williston, 1983) records in GBIF. Only 10 specimens, all from Japan.

Clogmia albipunctata (Williston, 1983) on BugGuide.


8 Responses to “Insect of the week – number 18”

  1. ardeans says:

    Our most recently collected specimen is almost as old as me?! I see these flies on almost a daily basis, including inside the bathrooms of Gardner Hall! I’m bringing my aspirator next time…

  2. Gunnar says:

    The recent taxonomical literature is unambiguous in placing this species in Clogmia.

  3. Thanks Gunnar, do you have a reference?

  4. Gunnar says:

    Psychoda albipunctata Williston 1893 was selected as type species for Clogmia Enderlein 1936, but was erroneously selected as type species of Telmatoscopus Eaton, 1904 by Vaillant (1971). This is probably one of the main reasons why the species still often ends up being called T. albipunctata, as Vaillant’s work is a very much used reference work in Psychodidae. Recent references placing it in Clogmia include Duckhouse (1978), Ježek (1984), Wagner (2004) and Ibañez-Bernal (2008).

    Nomenclature in the Psychodinae is, however, a very unstable and tiring affair. It is very easy to make mistakes, as opinions on what is “correct” fluctuate so much between authorities. I will not go into details of these questions; the controversies are (mostly) disagreements of formalities and semantics rather than about questions of phylogenetic relationships.

    Concerning Clogmia albipunctata, it has quite recently been recorded for the first time in such well-sampled areas as Germany (Werner 1997), the Netherlands (Boumans 2009) and Belgium (Boumans et al. 2009). As the species is very anthropophilous, these new records probably represent range expansions rather than insufficient previous knowledge; suggesting that the species currently is migrating northwards. The current Northern limit in Europe is probably in Denmark (where it is not yet recorded), but this is likely to change as the world is warming.

    - Boumans, L. 2009. De WC-motmug Clogmia albipunctata, een opvallend maar onopgemerkt element van onze fauna (Diptera: Psychodidae). Nederlandse Faunistische Medelingen 30: 1-10
    - Boumans, L., Zimmer, J-Y. & Verheggen, F. 2009. First records of the ‘bathroom mothmidge’ Clogmia albipunctata, a conspicuous element of the Belgian fauna that went unnoticed (Diptera: Psychodidae). Phegea 37: 153-160
    - Duckhouse, D. A. 1978. Non-phlebotominae Psychodidae (Diptera, Nematocera) of southern Africa. II. Subfamily Psychodinae: Neoarisemus and the brunettoid and telmatoscopid genera. Annals of the Natal Museum 23: 305-359
    - Enderlein, G. 1936. Klassifikation der Psychodinen (Dipt.). Deutsche Entomologische Zeitschrift 4: 81-112
    - Ibañez-Bernal, S. 2008. New records and descriptions of Mexican Moth Flies (Diptera: Psychodidae, Psychodinae). Transactions of the American Entomological Society 134: 87-131
    - Ježek, J. 1984. Nomenclatorical changes of some higher taxa of palearctic Psychodinae (Diptera, Psychodidae). Acta Faunistica Entomologica Musei Nationalis Pragae 17: 155-170
    - Vaillant, F. 1971. Psychodidae – Psychodinae. pp. 1-48 in Lindner, E. (ed.): Die Fliegen der Palaearktischen Region. Lief. 287. E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart
    - Wagner, R. 2004. Fauna Europaea Web Service. Available from
    - Werner, D. 1997. Studies on some moth flies (Diptera: Psychodidae) with the first record of Clogmia albipunctata in Central Europe. Entomological News 108: 273-282

    There will NOT be a prize for guessing which group of insects I am currently working with.

  5. Gunnar, thank-you so much for the insightful expertise and references! This is a wonderful addition to the post and clears up the confusion.

  6. Sorry, Andy and others.

    Gunnar did not really answer the question about this species and its proper name.

    There are no “correct” scientific names as all scientific names represent hypotheses which are encoded into classifications. Naturally, some hypotheses are better supported than others. And there are different ways of translating these hypotheses into classifications.

    In this case, it is not the scientific hypothesis but its translation into a classification. Today many specialists, like Gunnar, like to split classifications up more finely until they are virtually meaningless to all but specialists. This is why, for example, birdwatchers no longer use scientific names as they have no practical value.

    So, it is with the common drain fly. The last scientific revision of the local (USA) moth flies was by Larry Quate in 1955 and the last published list of them was in 1965. In both of these works, the drain fly was called Telmatoscopus albipunctatus. More modern specialists, like Gunnar, however, like to break up the old broad version of the genus Telmatoscopus into a number of smaller groups. Hence, the use of Clogmia albipunctata.

    When the Integrated Taxonomic Information System (IT IS) was being built back in the late 1980s, those specialists (blame me) decided to retain the older more useful classification of Quate, and, hence, the name Telmatoscopus albipunctatus.

    This situation of what is referred to by specialists as “Splitters versus Lumpers” but really should be Unitarian versus specialized, is now unfortunately too common. Recently examples are illustrated by Aedes aegypti versus Stegomyia aegypti (the Yellow Fever Mosquito) and Drosophila melanogaster versus Sophophora melanogaster (the fruit fly of genetics).

    So, in this case, users should feel free to use what name they feel is most useful to them. And I find that the old and proven Telmatoscopus albipunctatus of Quate remains the best.

  7. Thank-you Chris for the wonderful and insightful reply. Like you and all taxonomists, I have also encountered this issue in my work. I appreciate you exposing it here and offering a different opinion. As a self-proclaimed “lumper”, I agree with your sentiments, but will leave the debate of Clogmia versus Telmatoscopus to you, Gunnar, and the other Dipterists.

  8. Gunnar says:

    There are no “true” scientific names, however some names are more accurate than others. Retaining the nomenclature of Quate today is highly anachronistic, as the science of taxonomy has progressed a lot since the 1960’s. Most notable is the introduction of a theorethical framework (phylogenetic systematics), however technological advances (such as improved microscopy, DNA sequencing etc.) have also brought forth more potential taxonomic characters. Modern taxonomy aims to reflect the best current understanding of the animals (or plants’) relationships in the names of the taxa. Whereas Quate was an outstanding taxonomist, ignoring the work that has been done since his time gives truth to the charicature of taxonomy as an outdated and non-scientific discipline.
    Concerning ITIS, it is far too biased against North America to be useful for world systematics of Psychodidae (I cannot speak on other groups). It lacks two subfamily-level taxa, the nominal genera of two other subfamilies and several genera from other parts of the world. Unfortunately, there is not yet any world catalogue even of genera available; probably because the different authorities don’t agree on generic concepts.
    As for lumping vs splitting, I feel that lumping hides systematic understanding and makes genera more unmanageable for people working with more than one species at the time. It also aids the users of the taxonomy in that is produces more species-level revisions – revisions of genera with 2000 species does not happen as often as revisions of genera with 100.
    A good compromise (that I probably will be aiming for) is the use of specialised taxon categories that the regular public don’t care about – e.g. subgenera and species groups. This retains the advantages of splitting (nomenclatural accuracy at some levels) and those of lumping (nomenclatural stability at the levels people actually use).

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