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SCIARA TRITICI, COQ. A FLY INJURIOUS 

 TO SEEDLINGS. 



By P. W. EDWARDS, B.A., F.E.S., 

 and C. B. WILLIAMS, M.A., F.E.S. 



(Published by 'permission of the Trustees of the British Museum.) 



Until comparatively recent years few or no instances were known 

 of damage to plants by fly larvae of the genus Sciara, and even in some 

 recorded cases it was supposed that the injury caused by the Sciara 

 larvae was only of a secondary nature, and that they only attacked 

 parts of plants where decay had already begun to set in owing to the 

 attacks of some other pest. Recent investigations by several observers 

 in the United States have, however, shown that in a number of instances 

 the damage must be directly attributed to the larvae of some species 

 of Sciara. 



No definite records have been published on this subject in Britain, 

 and it has therefore been thought worth while to issue the following 

 notes on a species of Sciara which certainly causes damage to potted 

 plants in this country. Added interest is given by the fact that the 

 species in question has not previously been recorded in Great Britain, 

 or even in Europe, though it is quite uncertain where it had its original 

 home. 



In the autumn of 1911 specimens of a Sciara were sent me for 

 identification by Mr 0. B. Williams, from Merton, Surrey, where they 

 were damaging Primula seedlings. At that time I was unable to identify 

 these specimens with any described European species, and they were 

 in consequence pu1 on one side. The question was reopened in June 

 of the presenl year (1915) when living specimens of the same species 

 were received from Mr \V. 11. St Qnintin, of Rillington, Yorks, whose 

 young orchid plants had suffered from their attacks. I then studied 

 the literature more carefully and found thai the specimens were without 



