Of course, we phoridologists think that phorid flies (Insecta: Diptera: Phoridae) are just about the most fascinating group of organisms around. Some of the questions I am frequently asked about them are as follows:

Q: How many species of phorids are there?

A: There are about 3,000 described species of phorids, but the actual number is much higher. Published estimates by Disney range from 20,000-50,000; my own work on New World phorids has shown that there is at least 10 times the described diversity out there (thus at least 30,000 species).

Q: Who works on phorids?

A: Consult the Phorid Newsletters, also on this web page, to see a list of all people I know of who work on phorids. Really active workers on phorid taxonomy are few, mostly just Dr. R.H.L. Disney, from Cambridge University in England, and myself. Many students do graduate work on phorid systematics, but then get jobs doing something else (such as teaching in an unrelated biology field).

Q: Why don't more people work on such elegant creatures?

A: Phorids are small (1-7mm) and poorly known. Most of the keys don't work because there are so many undescribed species, and the frustration factor is large. Additionally, one genus, Megaselia, accounts for nearly half the family, and its taxonomy is a mess. Only the fauna of England can be approached with any degree of confidence, thanks to Disney's Handbook on the British Megaselia.

Q: Aren't all phorids just garbage feeders (or more recently I am asked "Aren't they all parasitoids?")?

A: No. In fact, Disney referred to them as "perhaps the most biologically diverse group of insects." They are a diverse assemblage of scavengers, herbivores, predators, parasites and parasitoids. However, the best known, most widely distributed species are the scavengers associated with humans (synanthropes).

Q: Which species do you most commonly get asked about?

A: No contest: 90% of the specimens sent to me for identification are Megaselia scalaris (Loew), an almost cosmopolitan scavenger that can develop in almost any organic material. Click here to see images of this species.

Runners up in the phorid popularity contest are Dohrniphora cornuta (Bigot) and Puliciphora borinquenensis Wheeler, both of which are also synanthropic, widespread scavengers.

Q: Are any phorids economically important?

A: Some phorids cause economically important damage to mushrooms and others have occasionally damaged other crops. Recent work on phorids as biocontrol agents for the imported fire ant in the southeastern USA might make phorids highly important in controlling these pests.

Q: What is a good general reference work for phorids?

A: The standard reference is Disney, R.H.L. 1994. Scuttle flies- the Phoridae. Chapman & Hall, Publishers.

Brown, B.V. 1995. Review of "Scuttle Flies: the Phoridae." Bulletin of the Entomological Society of Canada. 27: 41-42.

Brown, B.V. 1996. Review of "Scuttle Flies: the Phoridae." Proceedings of the Entomological Society of Washington. 98: 166-167.

Generally, I think the book is an excellent introduction to the family. There are only a couple of problems:

1) The alternative classification for phorids that I developed is not discussed, except to dismiss it as "premature" without further evidence. To get a more balanced account of phorid systematics and much more information about phorid phylogeny, refer to the following papers:

Brown, B.V. 1992. Generic revision of Phoridae of the Nearctic Region and phylogenetic classification of Phoridae, Sciadoceridae and Ironomyiidae (Diptera: Phoridea). Memoirs of the Entomological Society of Canada. 164: 1-144.

Brown, B.V. 1995. Response to Disney. Journal of Natural History. 29: 259-264.

2) Many phorids from the Neotropics (and I suspect tropical regions around the world) will not key out properly in the key to genera. This is not Disney's fault: the number of described phorids is still embarrassingly small, and our knowledge of the range of variation within genera is limited. Disney's key is a tremendous improvement over previous efforts.

Q: What is the best way to collect phorids?

A: It depends on what you mean by "best." All collecting methods have biases that influence the catch. My own preference is to use Malaise traps with alcohol as the collecting medium. These traps collect a huge number of specimens, often including extremely rare species that are not found otherwise. Some species are missed by Malaise traps, however (for an excellent summary, see Disney et al. 1982. Collecting methods and the adequacy of attempted faunal surveys, with reference to the Diptera. Field Studies. 5: 607-621), and Disney objects to Malaise trap catches on the grounds that they collect too many other insects, making them troublesome to sort. He prefers pan traps in some situations. For answers to some of these criticisms, and more information about Malaise trapping efficiency, see my paper about collecting methods:

Brown, B.V. and D.H. Feener, Jr. 1995. Efficiency of two mass sampling methods for sampling phorid flies (Diptera: Phoridae) in a tropical biodiversity survey. Contributions in Science. 459: 1-10. PDF

As well as my discussion in Phorid Newsletter #5, on this web site.

Q: What is the best way to prepare phorid specimens?

A: Here Disney and I really diverge. Disney is a strong advocate of slide mounting phorid specimens using Berlese fluid, a non- permanent, but convenient medium. After receiving considerable criticism in the literature (see references below) he has recently acknowledged that a more permanent medium, euparal, is probably better.

My preference is to critical-point-dry specimens and glue them to the side of insect pins. I either use a normal critical- point-drier or chemical drying agents like HMDS.

Both of us agree that phorids should not be air-dried, and that they should be collected into 70% ethanol.

Articles about slide mounting:

Disney, R.H.L. and D.H. de C. Henshaw. 1988. Berlese fluid for slide-mounting insects. Antenna. 12: 106-107.

Noyes, J. and A. Polaszek. 1989. Berlese or balsam? Antenna. 13: 2.

Disney, R.H.L. 1989. Berlese or balsam? Antenna. 13: 48.

Upton, M.S. 1993. Aqueous gum-chloral slide mounting media: an historical review. Bulletin of Entomological Research. 83: 267-274.

Q: Where are the important phorid collections?

A: Two of the most significant phorid collections are those of Hermann Schmitz, at the Zoologisches Museum und Forschungsinstitut Alexander Koenig, Bonn, Germany and Thomas Borgmeier at the Museu de Zoologia, Universidade de São Paulo, Brazil. They were built by the two great phoridologists of the earlier part of this century, both of whom described hundreds of phorid species (Borgmeier described nearly 1,000 phorids).

Other important earlier collections are in the Natural History Museum in London, England, the United States National Museum and Harvard University in Cambridge, Massachusetts, USA.

Of course, the collections assembled by Disney and myself are also extremely large, and still growing. Disney's collection is at the University of Cambridge, England. My collection is at the Natural History Museum of Los Angeles County (LACM), Los Angeles, California, USA. The LACM collection contains an extremely large amount of Neotropical material, including the largest collection of ant-decapitating flies (genus Apocephalus) in the world. Also, the USNM and Harvard collections are on long-term loan to the LACM, to support my research.

Q: Are you interested in receiving phorid specimens?

A: Definitely. Few areas are sampled sufficiently, even in North America and Europe. I especially welcome Malaise trap samples from anywhere in the world, or parasitoid phorids associated with hosts. Please let me know if you have such specimens that you are willing to send me.

Q: Are you willing to identify phorid specimens?

A: Sure. Please contact me first, and let me know how many specimens you want to send. Specimens of some genera, such as many Megaselia, are impossible to identify at this time.

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