50 



In a letter published December 3, 1898, Mr. Davison, mentioned above 

 as having sent specimens of this insect to us for identification, states 

 that his experience with this maggot convinces him that it is the worst 

 enemy the violet grower has to contend with, owing to the extreme 

 difficulty experienced in its destruction without injury to the plant. 

 He says: 



It secretes itself in the crown of the plant; the leaves as they come up are tightly 

 curled, and when unfolded there will he found 6 to 8 small white maggots. On 

 some plants yon can pick off the young leaves until the crown is hare. Loosing the 

 crown will cause the side crowns and runners to start; the latter must he taken off. 

 The maggot seldom appears on the side crowns, giving them a chance to make good 

 plants. The llowers will not he as large as crown flowers. 



. I find when the maggot leaves the plant it goes into the ground. As proof of this, 

 I placed 40 or 50 of the leaves containing maggots on a pot filled with soil, covering 

 the soil with glass, expecting in this way to see the maggot in the chrysalis state. 

 At the end of two weeks, wanting to send some specimens to the Division of Ento- 

 mology at Washington, I removed the glass, hut the maggots were gone. I turned 

 the soil out of the pot and found maggots all through the soil in the same state in 

 which they left the leaves. 



He also expressed the belief that the fly was introduced with manure 

 purchased from a person who collected garbage, as no flies were seen 

 in his greenhouse previous to the introduction of this manure, and the 

 maggots were observed only where it was used. Further experience 

 is necessary to confirm this opinion. 



The subject of the so-called gall flies which affect violets has also 

 received mention by Mr. B. T. Galloway in his recently published hand- 

 book on violet culture under the heading "Gall Fly Maggots." The 

 nature of the injury is there described and remedies suggested. This 

 account also includes a half-tone illustration reproduced from a photo- 

 graph showing the twisted leaves of violets. 



This insect, although belonging to the same family as the two spe- 

 cies already referred to as also attacking violets in Europe, pertains to 

 a different genus; and while its work is very similar to that produced 

 by the Cecidomyia affinis, yet a comparison of the adult gall-gnats with 

 the description of the last mentioned species reveals the fact that the 

 two are very distinct, hot only differing in the venation but also in the 

 structure of the antennae. Following is a description of our species : 



Diplosis violicola uew species. 



Antennae in both sexes three-fifths as long as the body, 14-jointed 

 (2x12), the first two joints subequal in length, each as broad as long; 

 third joint more than twice as long as the second and more slender, 

 other joints becoming successively slightly shorter except the last one; 

 joints 3 to 13 each slightly constricted near the middle, narrowed at 

 the apex into a petiole, which, on the thirteenth joint, is almost one-half 

 as long as the thickened portion of the joint; 2 whorls of bristly hairs 

 on each of the joints from 3 to 13 inclusive, one near the base, the 

 other near the apex of the thickened portion. Head and thorax 



