December, '16] HUNGERFORD: SCIARa MAGGOTS INJURIOUS 545 



It was early noted that the flies showed a marked preference for soils 

 having an abundance of moisture. Plants alike in every particular 

 save in the amount of water received showed in one series an average 

 of seventeen for the wet ones and none for the dry — a good suggestion 

 for control, for besides rendering the soil unattractive to adults, the 

 maggots already in the soil perish. However, many plants will not 

 stand the lack of water and so experiments were made to see how well 

 control could be affected by sanding the surface of the pots and water- 

 ing from below. Besides presenting a surface unattractive to the egg- 

 laying of the adult, the inability of the larvae newly hatched to get 

 down through the sand was demonstrated. 



It also appears that pupse already found in the soil have difficulty 

 in getting through the relatively dry sand barrier. One hundred 

 pupse were placed in each of six pots, three of which were covered with 

 one-half inch layer of rather coarse sand and water supplied from be- 

 low. The counts were 3 — 1 — 0, for sanded pots and 97 — 92 — 94 for 

 the check pots. 



The depreciation in the former case may be normal mortality, or it 

 may mean that some were injured in transferring them to the pots. 

 In practical application of this method under conditions prevailing 

 in our homes where ferns and begonias often predominate, the judi- 

 cious combination of the methods above noted have given very satis- 

 factory results. 



In all the cases that have come to our attention, the presence of 

 these flies has seemed due to soils rich in barnyard manure or treated 

 with dried blood fertilizer. In one instance a lady who found that a 

 large potted Lantana was supplying the flies that had been noticed 

 all the fall, thought to help matters by emptying the remains of the tea- 

 pot upon the inch of sand that had been placed on the surface of the 

 soil. Some time later we were called in to see where the flies came from. 

 A three-fourths inch layer of tea leaves was found, in the lower layers 

 of which were hundreds of maggots. The maggots had gnawed the 

 base of the tree somewhat but there did not seem to be maggots or 

 pupse in the sand below. Remedial measures were simple enough. 



Destroying the Maggots in the Soil 



All of the first efforts at control were directed toward destroying 

 the maggots as they existed in the soil. The recommendations found 

 in the literature were followed but with slight success. These included 

 the use of lime water, kerosene emulsion, hellebore, carbon bisulphide, 

 etc., and to this list were added experiments with: Black Leaf 40, in 

 strength from one part to 1,000, and one part to 100. Sodium thio- 

 carbonate, whale oil soap, borax water, and experiments in which the 



