DIPTEROUS PLANT-MINERS IN THEIR PERFECT STATE. 291 



imiralis), as also from dandelion and nipplewort [Lapsana). It is 

 probably, therefore, the most polyphagous of the group. This 

 bears out the remarks of Scholtz and Hardy, who find the fly 

 mining such various vegetation. Fully a dozen distinct plants 

 afford food to P. alhiceps, according to their observations. 

 Another beautiful fly is Trypeta onopordinis, which mines our 

 celery leaves, often damaging the crop, though not so seriously as 

 to interfere with its growth. It was first described by Linnaeus, 

 in his 'Fauna Suecica,' in 1771 ; he found it mining the leaves 

 of Hcracleum. . It is now called Acidia heraclei, L. The affected 

 celery leaves were gathered on the 17th of July, and the imagines 

 emerged from pupahood on the 17th of August. 



Crucifer^. — Though not a miner, but a root-feeder, I would 

 draw attention to ft fly, Chortophila floccosa, Macquart, which is 

 destructive in the larva state to our young savoys. The plants 

 that were affected died from the loss of their rootlets. I bred 

 both male and female. The tufts of hairs on the posterior thighs 

 serve to identify the species. Dr. Meade remarks that nothing 

 of its life-history in connection with its food-plant has been 

 previously recorded. 



Labiate. — I succeeded this year, for the first time, in rearing 

 the gall-gnat of the ground-ivy. It is instrumental in forming 

 those reddish purse-like galls on the leaf of the ground-ivy. 

 I gathered the galls in the autumn of 1880, and the imago put 

 in an appearance on the 28th of the May following. The 

 structure of the gall itself is as marvellous as it is mysterious. 

 The opening of the cone-shaped purse is on the under side of the 

 leaf, and in this purse the larva lives, feeds, and pupates, putting 

 on wings, as I have said, in the following May. The name of the 

 gall-gnat is Cecidomyia hursaria, Bremi. 



Chenopodiace.f:. — Here, again, we find probably the whole 

 family mined by Chortophila beta, Curtis, the pest of our man- 

 gold fields. I have bred the identical fly from Chenopod-spinach, 

 mangold and beet this year, and this is possibly not surprising, 

 as the juices and mucilage of the group would doubtless make it 

 generally available for culinary purposes, like the spinach. I 

 hear, indeed, of a sea-coast Chenopod (Schoheria maritima) 

 furnishing food to C. beta on the Sussex coast. Thus it is more 

 than probable that the fly may adapt itself to circumstances in 

 obedience to the season and its food-supply. 



