164 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



flower buds on the apple trees were on the point of opening. These 

 observations prove that there is now no question but that the egg 

 blisters so carefully measured by Franklin last fall on the branches 

 of the trees in the apple orchard were those of E. niali. 



June 4th. First young of the second brood collected on alfalfa. 



July 17th. Adults first appeared from the young of June 21st; 

 possibly they were present a few days earlier, for experiments and 

 observations of 1907 and 1908 both show there is an average of 

 twenty-two days in the nymphal stages. 



Some of these adults of the second brood were placed on selected 

 box elder seedlings, free from any insect, in lamp chimney breeding 

 cages, for two days. On July 31st the first young appeared. The 

 egg stage at this season of the year varied from seven to thirteen 

 days, nine and one-half days being the average. If we add twenty-two 

 days to this date, the time of hatching the egg, we get August 22d, 

 the date on which the first of the third generation became adult. 



Winter egg blisters were not found until fairly late in September, 

 therefore it would seem that these adults of the third brood lay eggs 

 for a fourth summer generation. Further, the finding of nymphs 

 nearly as late as November 1st, 1908, would also indicate a fourth 

 brood or partial fourth brood in Minnesota. 



Economic Work : Doctor Franklin conceived the idea of a hopper 

 dozer to be carried along nursery rows by two men. This hopper 

 dozer consisted of a frame of wood, covered with light canvas, the 

 canvas being covered inside with either crude oil, or some sticky 

 substance. Such a machine was constructed, having a padded cross 

 bar in such a position as to jar the tree, the purpose being to cause 

 the hoppers to fly off and come in contact with the oil or other sub- 

 stance on the inside of the canvas. We found, however, that this bar, 

 which was to serve as a bumper, was too far forward, and caused the 

 tree to bend forward and strike the tree ahead, frightening the leaf 

 hoppers from that tree, and hence nearly nine tenths of the hoppers 

 escaped. Learning from this year's experience we perhaps can 

 remedy these defects, and try the same thing w^ith certain modifica- 

 tions next year. The crude oil which we used was not satisfactory, 

 but the tanglefoot we found to be excellent. We made an imperfect 

 trial of lights, with negative results. 



It has also occurred to us that in the spring of the year nursery 

 trees might be sprayed with a resin compound, or some sticky sub- 

 stance in connection with some of the standard solutions used at this 

 time of the year, so coating the branches with a material harmless to 

 the tree and preventing the emergence of the nymphs. 



