FAIRY FLIES AND THEIR HOSTS. 



45 



FAIRY FLIES AND THEIR HOSTS. 

 By Fred Enock, F.L.S., F.E.S., F.R.M.S., F.R.H.S. 



[Read August 12, 1913 ; Mr. Geo. Gordon, V.M.H., in the Chair.] 



To some the title of my lecture may appear to be somewhat ambiguous, 

 so I will at once say that the family of Fairy Flies consists of the most 

 minute winged insects known to science — some of them measuring 

 not more than one-ninetieth of an inch in length ! (Fig. 9.) 



It was not until the year 1833 that they received any attention 

 from entomologists, who evidently considered them too small to 

 merit a name. 



In that year they were named by the late A. Halliday and 

 Francis Walker, and were placed in the family of the Mymaridae, 

 consisting of about twenty species. Unfortunately for science, no 

 figures were given, but only short Latin descriptions from which 

 only the genera could be identified. From this fact, it is not to 

 be wondered at that few students were found to work at this much- 

 neglected family. 



In the year 1876 the Royal Microscopical Society held a conver- 

 sazione, and under one of the microscopes was exhibited by the late 

 Frederick Fitch a m.inute insect, described as " A Fairy Fly caught in 

 a Spider's Web." (Fig. 10.) 



It was the sight of this most exquisite insect that first determined 

 the writer to commence the study of the family, but this was easier 

 said than done, for the materials were so meagre. The where- 

 abouts of Halliday's collection was unknown for several years, and 

 when found in the Dubhn Natural History Museum it was in such a 

 dilapidated condition that it was not of much service. There were 

 167 specimens, mounted on small pieces of card, but so dirty and 

 covered with crystals that it was next to impossible to name 

 them until I had made an enlarged drawing of each specimen under 

 the microscope, showing as much as possible the various parts, but 

 here again the accumulated mass of dust and crystalHzation of nearly 

 a hundred years had completely obliterated the delicate joints of 

 the antennae and tarsi. In spite of these drawbacks, I was enabled 

 to identify the genera to which they belonged, but several of the 

 most interesting types were missing from this collection. 



The following names are those of Halliday's genera : Ooctonus, 

 Litus, Mymar, Anaphes, Anagrus, PGlynema, and Eustochus. 



To these, in 1846, F. Walker had s^ddedArescon, Alaptus, Panthus, 

 and Caraphractus. 



