530 



JOURXAL OF ECOXOMIC EXTOMOLOGY 



r^'oi. 8 



feel that we have the grasshopper situation well in hand and that, 

 thanks to you, the problem is solved.'' 



Another experiment carried out hy I\Ir. Theodore D. Urbahns at 

 Gustine and San Diego, Cal., resulted equalty satisfactorily. In 

 this case the species involved were M. differentiaUs, M. unijormis, M. 

 destructor, and Camnula pelludda. The usual formula was used by 

 Mt. Urbahns, except that 6 lemons were used for each 25 pounds of 

 bran, with 2 quarts of cheap syrup and 3 gallons of water. ]\Ir. 

 Urbahns was able to protect alfalfa fields where the plants were IS 

 inches high and the insects feeding destructively along the border of 

 the field. In his experiments he found that ahalfa meal was about 

 equal to wheat bran in value, thus giving an alternative where farmers 

 can obtain alfalfa meal more readily than wheat bran, the price being 

 practically the same. Sugar beet pulp was also used but its effective- 

 ness was found to be of shorter duration than that of the bran or alfalfa 

 meal. 



Ybvj satisfactory results were obtained with this poison bait mixture 

 by Mr. E. L. Barrett of the Pasadena, California, laboratory in ex- 

 periments carried out hj him in the Imperial ^^alley, covering two 

 areas, one of about 20 acres, on a ranch at HoltsAdlle; and another of 

 about 10 acres, near Brawley, Cal. Seventy-two hoiu"s after the 

 poison was put out, there were found on an average of about 150 dead 

 grasshoppers per square 3^ard. As the effects of the poison would 

 extend beyond that time, it is free to presmne that the destruction 

 of these insects were still greater than these figures would indicate. 



An attempt to control grasshoppers hy these poisons in the ^dcinity 

 of Tempe, Ariz., was ineffective, and we had a recurrence of the con- 

 ditions where an expert entomologist failed to secure satisfactory 

 results with the poison. Later, however, experiments were carried 

 out in this same locality, the only difference in the bait being that 

 instead of an ordinary' good grade of molasses, sorghum molasses was 

 substituted. Otherwise the same formula was used as that employed 

 by Mr. Urbahns, excepting that 2 gallons of water per each 25 pounds 

 of bran was used in preparing the mixtm^e. The application was 

 made August 12. Two days later the average count over the field was 

 167 dead grasshoppers to the square rod, while as a final result 95 per 

 cent were killed. Here the species involved was chieflj^ Melanoplus 

 differentiaUs. Thus it has been learned that the chief cause of failm-e 

 has been in that, when this poison was used against the j^oung grass- 

 hoppers, too small amounts of fruit were utilized in making the bait, 

 and the failures when used against full-grown grasshoppers were largely 

 in that the baits were lacking in moisture and hence less attractive 

 when the grasshoppers began to feed upon them. Then, too, there 



