The Scottish Naturalist. 285 



The larvae are small and rather slender, ringed, soft, fleshy, 

 worm-like creatures, with no distinct head. They are white, or 

 intermediate in colour between white and deep orange-red. 

 Many of them live in decaying fungi, or wood, or in any other 

 decaying matters ; others live, as guests, in galls formed by gall- 

 making Cecidomyidce, or by Gall-mites, or, less often, by insects of 

 other groups ; but a large proportion form galls for themselves, 

 and live singly, or several together, in the central cavity, or among 

 the abortive leaves, stems, or other parts of which the gall is made 

 up. Others feed upon plants without producing conspicuous dis- 

 tortions in them, e.g., the " Hessian Fly " (C ecidomyia destructor) 

 in Barley and Wheat, and the many species which live in fruits 

 (e.g., C. Pisi in pea-pods), or among the flower-beds of the Com- 

 posite. Several of the more important field and garden crops 

 suffer greatly from the ravages of Cecidomyidce ; but the gall- 

 makers are far less hurtful to cultivated plants than are those 

 Cecidomyidce that feed in them without producing galls. 



As there will be no opportunity of again referring to the latter, 

 I shall here enumerate those that have been observed to be 

 peculiarly hurtful to farm and garden produce in Europe, and 

 which may therefore be expected to occur in Scotland, or have 

 actually been observed here. They are : On wheat and other 

 cereals, in the flowers or at the joints of the stems, the 

 "Red Maggot" or "Wheat Midge" (Cecidomyia Tritici 

 Kirby), the " Orange Midge " (Dip>losis aurantiaca Wagn.), the 

 notorious " Hessian Fly " (C. destructor Say), and a fly without 

 a popular name, known as Diomyza obfuscata Mg., which was re- 

 corded by the late Andrew Murray from the south of England. 

 Another species, Dijylosis equestris Wagn, lives in saddle-shaped 

 swellings on the stalks below the slightly discoloured leaf-sheaths. 

 The larvae of another, named C. cerealis Sauter, have been observed 

 to live in multitudes between the leaf-sheaths and the stalk, and 

 do considerable injury. Peas, both in field and in garden, are 

 liable to injury from larvae of Diplosis Pisi Winn., the "Pea 

 Midge," which feed on the young seeds. Cabbages and Turnips 

 have the seeds destroyed in the same way by larvae of C. Brassicae 

 Winn., and of Diplosis cchracea Winn. Pear trees lose many of 

 their young fruits from the attacks of larvae of C. nigra Mg., and 

 C. pyricola Nordl. ; and their leaves are injured by the inrolling 

 and distortion of the margins by C. Pyri Bouche. This list 

 might be extended still farther ; but the above will suffice to 



