THE INSECTS OF THE DIPTEROUS FAMILY PHORID.E IN 

 THE UNITED STATES NATIONAL MUSEUM. 



By J. R. Malloch, 



Of the Bureau of Entomology, United States Department of Agriculture. 



INTRODUCTION. 



The species of this family are for the most part very small, black, 

 or yellow flies that are easily overlooked, and the life history of which 

 is very little known. It is considerably more than a century since 

 the first species was described, and even now but little is known of 

 its habits. If one accepts jiorea Fabricius (1794) as synonymous 

 with abdominalis Fallen, wliich systematists are averse to doing, or 

 rujipes Meigen, as examples of common species, it will be found 

 that very little is known about their larval habits. It is rarely 

 indeed that complete records of their life habits are found, and a list 

 of those so recorded would not occupy a page of this pamper. Those 

 that have been reared have been for the most part upon fungi, or 

 upon dead or decaying animal or vegetable matter. Some species 

 have been reared from snails and a few from the bodies of bees, ants, 

 or beetles, but whether the whole of those species were true parasites 

 or not is a matter for conjecture. Several species are myrmecophi- 

 lous, and in this section occur the most peculiar genera belonging to 

 the family, the females being apterous, or semiapterous, and resem- 

 bling the Pulicidse more than the Phoridae. The general bod}^ of the 

 family have wings in both sexes, and their peculiar neuration sepa- 

 rates them from any other Diptera, although they superficially 

 resemble Scatopse in wing neuration. This is a genus belonging to 

 the Bibionidte, in which Fabricius described his species ^Zor^'a (1794), 

 and the similarity in neuration A^ery probably was responsible for his 

 placing it here. In Phoridae the costa extends to only the middle, or 

 slightly beyond, or short of the middle of the wing, the thick costal 

 vein being combed with long bristles in most species, and the only other 

 thick veins are the first and third longitudinal veins, which join the 

 costa at about its middle and its apex, respectively. The mediastinal 

 vein is present in some genera and ends in the first longitudmal vein; 

 the humeral vein is always present, and the second longitudinal vein 



Proceedings U. S. National Museum, Vol. 43— No. 1938. 



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