December, '16] HUNGERFORD: SCIARA MAGGOTS INJURIOUS 541 



eating the root hairs of various rootlets and devouring sound, growing- 

 roots. ^ 



Dr. Johannsen states that: 



Florists look upon these little gnats with a suspicion which is more than justified. 

 as the fact that .the larvae feed upon the tender roots of potted plants is well estab- 

 lished. 



He further states: 



I have found larvse in potatoes, feeding on the sound tissue, on the roots of various 

 grasses, and in tulip bulbs. 



The maggots of those species we have studied are almost omnivo- 

 rous as to feeding habits and the injury to plants becomes apparent 

 only when they are relatively abundant. We have watched a maggot 

 as it devoured the dead pupa of one of its own species, nibbled at 

 flakes of decaying organic matter and then, coming to a live healthy 

 root of a wheat plant, proceed to devour it, following its windings for 

 some distance, eventually eating all of the three inches of root that 

 lay against the glass. Maggots newly hatched seem to prefer the root 

 hairs and often clean a rootlet for some distance, and then work upon 

 its surface. 



An examination of the root system of an infested plant often shows 

 it severely curtailed. In Plate 42, figure 6, is the photograph of a gera- 

 nium where the maggots were abundant. Plate 42, figures 1 and 3 

 show their work upon a geranium slip. 



There can be no doubt as to their injurious work. 



This lack of thrift of house plants is more often due to the work of 

 these maggots in the soil than is commonly supposed. Plate 42, 

 figure 2, shows some geraniums that have been injured. In one 

 large conservatory the majority of the plants were ruined. Among 

 them were a beautiful eleven-year old fern, many begonias, colias, 

 etc. 



Drs. Chittenden, Hine, and others have reported injuries to peas 

 growing in flower pots, and to lettuce, cucumbers and carnations. 

 Dr. Hine states that they were living in the stems of the carnations. 

 Dr. A. D. Hopkins has called attention to their work upon potato 

 tubers. Dr. Forbes has called attention to their injury to seed corn, 

 and the roots and bulbs of various kinds of flowering plants. Coquil- 

 lett and Lintner mention them as being injurious to wheat, and v/% 

 have in our own economic collection of insects, some Sciara specimens 

 taken from wheat fields at Solomon, Kansas. They have been several 

 times reported as working upon grass roots and we have found them 



1 These observations have been corroborated by Dr. Charles A. ShuU, Associate 

 Professor of Plant Physiology, and others. 



