544 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



the surface of the pot and "play possum" if disturbed. They are 

 often found in houses where a few plants are kept during the winter 

 months, and, as a rule, cause little concern. However, when they are 

 being bred in large numbers in the favorable soils of the conservatory, 

 they become a nuisance invading all parts of the house and at this 

 time become especially annoying on the dining table where their 

 accidental landing in butter and cream becomes somewhat trying to 

 even the less fastidious. 



Control Measures 

 The experiments for the control of these insects involved: 1st, pro- 

 tecting the plants by the use of repellents; 2d, destroying the maggots 

 in the soil by the application of contact insecticides and stomach 

 poisons; 3d, destroying the adult flies by the use of traps and poison 

 baits. 



Repellents 



In this series of experiments, small geraniums in three-inch pots were 

 used. The surface of the soil was covered to a depth of from one- 

 fourth to one-half inch with various substances such as flowers of 

 sulphur, pyrethrum powder, coarse sand, etc., and then exposed in a 

 place where there were many flies and other similarly potted plants as 

 checks. All of these plants were watered with like quantities of water 

 and watered from the saucers. The results were not startling, though 

 there were one hundred and fifteen dead flies near one pyrethrum pot. 

 When the soil was examined the average number of maggots per pot 

 were as follows: 



Pyrethrum 5 



Dried blood 114 



Sand 



Sulphur 



From subsequent experiments it is evident that the attractiveness of 

 the dried blood might have lowered the other counts somewhat. For 

 in this connection it may be stated that as a result of exposing plants 

 whose soils contained dried blood fertilizer and plants whose soils were 

 ordinary garden soils, the ratio was an average of seven hundred 

 and fifteen maggots per each pot to seven maggots. The larger num- 

 ber appearing in the soils containing dried blood. ^ 



^ One three-inch pot used in this as a trap was exposed a few days and then the 

 surface of the soil carefully searched for eggs. The egg clusters were more numerous 

 in a crevice between the pot and the dirt and in a similar place at the base of the 

 plant on the shady side. The eggs in this case were arranged in clumps as follows: 

 8, 7, 5, 1, 15, 20, 15, 9, 21, 5, 9, 3, 5, 10, 16, 5, 7, 5, 2, 9, 5, 6, 3, 7, 2, 15, 8, 6, 2, 1, 3, 

 17, 5, — a total of 252 eggs, an average of 8— eggs to the cluster. 



