TtJRNIP GNATS. 115 



Vegetables, and those of the T. hiemalis, or Whiter Turnip Gnat, are 

 more especially to be found in decaying Turnips. The gnats are very 

 often to be seen in winter (or from October onwards) floating or dancing 

 up and down in the air, in great numbers at one spot, in fields or gar- 

 dens ; and appearances of the Winter Gnat are supposed to be so much 

 influenced by weather that this insect was one of the kinds selected by 

 the Meteorological Society for report in their yearly observations of 

 natural history phenomena. I have often watched the numerous 

 parties of what appeared, without special examination, to be the 

 common Winter Turnip Gnat; but the T. regelationis (the Thaw Gnat, 

 as the scientific name may be rendered) is so exceedingly like the 

 hiemalis, that I think it very likely both kinds might be present. 



So far as is shown by the regularly recorded habits of the Winter 

 Gnats, the infestation cannot be called injurious; rather the reverse, 

 for the maggots, living in putrid and moist parts of the Turnip-bulb, 

 help to get rid of foul useless matter. But though their history was 

 made out many years ago, it may be worth while to give a few obser- 

 vations, as their presence is apt to be confused with several common 

 Turnip attacks, or fungoid diseases, which they have nothing to do tvith. 



The maggots are of the shape figured at p. 114, legless, cylindrical, 

 tapering gradually to the head end, which is very pointed, and largest 

 towards the tail, which is blunt and rounded, not j^ointed. The colour 

 yellowish, and the length not quite half an inch. These are to be 

 found in small numbers, or rather parties, in rotten parts of the bulb. 



The chrysalids (see figures) show the shape of the wings, and to 

 some degree other parts of the insect maturing, within the thm outer 

 film. The little gnats are brownish-grey, the thorax (body between 

 the wings) with four brown or fuscous stripes ; the two wings iridescent 

 and glassy, of a yellowish tint, and spotless, longer than the body of 

 the gnat, and lying flat when at rest. The legs long and slender ; 

 head small and globular, with mouth forming a little beak, slender 

 neck, and two lateral black eyes, and antennae, or horns, long and 

 thread-like. 



The "Thaw Gnat" is almost precisely like the above, excepting in 

 having a brown spot on each wing ; but I am not aware of this kind 

 having been definitely noticed as bred from rotten Turnips, until in 

 the course of October of 1893, the attention of Mr. W. Sims, of 

 Gourdas, Fyvie, N.B., was attracted by the large number of decayed 

 roots in the Turnips which he was gathering, and on examination 

 found these to be much infested by small maggots. Without entering 

 at length into Mr. Sims' observation, ''^ I may mention that of these 

 larvsB some still remained unchanged to gnat condition at the end of 



* See ' Banffshire Journal ' for Tuesday, May 1st, 1894. 



