232 



Maine Agricultural Experiment Station. 1917. 



quito wire, a layer of pyrethrum was placed on the ground 

 around the bottom of the cages, and kerosene oil was poured 

 on the soil outside of the layer of pyrethrum. Table 27, shows 

 the results with each formula. 



It was found that ants were coming into the cages around 

 the base of the branches which the cheese cloth did not cover. 

 Besides the dead trypetids which were devoured or carried away 

 by ants, there were others which did not drop on the cheese cloth. 

 Some of the poisoned flies fell between the branches, then worked 

 their way under the cheese cloth and died, others died on the 

 leaves. The daily record of the death rate of the fruit flies is 

 therefore, not complete. 



Small quantities of sodium arsenite added to diluted molas- 

 ses were tested under field conditions. As many of the fruit 

 flies rested on the sides and top of the cages in the previous 

 experiments, it was decided in this test to spray the remedy 

 through the mosquito wire of the cages on to the foliage of the 

 enclosed currant and gooseberry bushes. Table 28, indicates the 

 results obtained. 



TABLE 28. 



Death Rate of Adults Confined in Cages Enclosing Bushes 

 Sprayed With Sodium Arsenite in Diluted Molasses. 



Molasses 



Sodium 



Arsenite 



(gr.) 



Water 

 (gal.) 



Death Rate of Flies 



(pt.) 



8 hours 



1 



2 Days 





2 



1 



1 

 1 



9 flies 

 29 flies 



4 

 3 



16 Flies 

 Flies 



Too much emphasis, however, should not be attributed to 

 any of the experiments carried on under field conditions, because 

 the fruit flies were in captivity and in feeding were forced to 

 consume the poisoned bait. Again, some of the trypetids may 

 have died due to the exposure to sunshine and not to the effect 

 of the poison. 



Three currant bushes not enclosed in cages were sprayed 

 with the poisoned sweet, using one gram of sodium arsenite, 

 one-half pint of molasses and one gallon of water. Cheese cloth 

 was spread on the ground below the bushes, but not a single 



