News from the Bat Cave! – Monster flies back from the dead!

Yesterday we got some exciting news from colleagues at the Smithsonian Natural History Museum in Washington, DC.  Two African dipterists (fly scientists), Robert Copeland and Ashley Kirk-Spriggs,  have re-discovered one of the strangest flies ever found - Mormotomyia hirsuta (literally “terrible, hairy fly”).  We’re looking forward to some more details from them, but in the meantime, here’s a picture of the beast that they emailed out, next to a drawing from the original description in 1936:

Mormotomyia hirsuta, the “terrible hairy fly.”

Drawing from original description.

As you can see, this is a pretty strange fly.  It is large (over 1cm), covered with yellow hairs, and has reduced eyes and non-functional wings (the two narrow straps sticking up from the thorax).  It is only known from a single cave-like rock cleft in Ukazzi Hill, Kenya (map), where it feeds on bat guano. In 1948, V. G. L. van Someren went to the type locality in hopes of finding more specimens and studying the biology.  It’s fascinating to read his account, as published by van Emden in 1950:

The species occurs in a cleft from top to bottom in a large boulder on Ukazzi Hill (Garissa District, Kenya). This cave-like cleft, which isabout a yard wide, with its horizontal and oblique side-cracks is inhabited by unidentified bats. When Dr. van Someren visited the spot, heavy rains had washed down large quantities of bat droppings into the bottom of the “cave” and into a recess in the rock, where they formed a sodden mass. “Literally hundreds of this curious fly swarmed on the walls and around the mass of bat dung; males predominated, but hundreds of females were noted. On the rock margin around the soaking dung were hundreds of pupae, and from some of these flies were actually emerging and crawling up the walls.” Some were seen in copula. Dr. van Someren tried in vain to obtain some of the bats for identification by firing into the cave. Only stones fell and more fies came floating down, the fall of the males being apparently much slowed down by the long hairs, and occurring in a slight spiral line. The lack of prestomal teeth and the large soft labella of the mouthparts (fig. 2) indicate that the adults must feed on readily-available liquid or semi-liquid matter, such as the juices of the excrements and perhaps sweat of the bats. Males allowed to crawl on the back of the hand were seen by Dr. van Someren to apply their mouthparts to the skin and “seemed to be interested only in surface sweat.”

van Someren sent specimens to museums all  over the world, where they have continued to puzzle dipterists ever since.  The species is still placed in its own family (Mormotomyiidae), and we still don’t know what other flies (if any) it is closely related to.  I’m sure more fascinating details of this rediscovery will be coming out soon.

This is a good time to mention another amazing recently re-discovered fly, the European Thyreophora cynophila (family Piophilidae).  This is another large, interesting fly, which feeds on carcasses of large mammals (“preferably odd-toed ungulates”) in advanced decay .  It was described in 1794, but was never collected again after 1850, and had long been presumed extinct.  You can learn about this discovery here:

The long-lost Thyreophora cynophila, rediscovered in Spain (from Carles-Tolrá et al. 2010).

Thyreophora cynophila, by Jacob Sturm (from Insekten Deutschlands, 1794)


Austen, E.E. 1936. A remarkable semi-apterous fly (Diptera) found in a cave in East Africa, and representing a new family, genus and species. Proc. Zool. Soc. Lond. 1936 : 425-431.

van Emden, F.I. 1950. Mormotomyia hirsuta Austen (Diptera) and its systematic position. Proceedings of the Royal Entomological Society of London. Series B, Taxonomy 19 (7-8): 121-128. (link)

Martin-Vega, D., A. Baz, and V. Michelsen. 2010. Back from the dead: Thyreophora cynophila (Panzer, 1798) (Diptera: Piophilidae) ‘globally extinct’ fugitive in Spain. Systematic Entomology 35: 607-613. (link)

Carles-Tolrá, M, P.C. Rodríguez, and J. Verdú. 2010. Thyreophora cynophila (Panzer, 1794): collected in Spain 160 years after it was thought to be extinct (Diptera: Piophilidae: Thyreophorini). Boletín de la Sociedad Entomológica Aragonesa (S.E.A.) 46:1-7. (link)

UPDATE (12/22/10):

It’s official! Some of you probably saw the news releases on the internet a couple weeks ago, but if you didn’t, here’s a couple links:

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2 Responses to “News from the Bat Cave! – Monster flies back from the dead!”

  1. Thyreophora cynophila bears a striking resemblance to Bromophila caffra (Platystomatidae) from Africa.

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