CACTUS SOLUTION AS AN ADHESIVE. 7 



paste form was used. Very favorable results were obtained with 

 ferrous arsenate in most cases, while the results with iron arsenite 

 were not quite so good. The following tables give results of the 

 experiments conducted in the insectary with each of the arsenicals 

 here mentioned. 



On March 1, 1914, a cabbage plant was sprayed with ferrous arsen- 

 ate at the rate of 1 pound to 40 gallons of water, and as soon as the 

 poison had dried on the leaves, or at 6 o'clock p. m. the same date, 

 four Diabrotica balteata were encaged on the plant. 



TABLE) VII. 



-Experiment No. 16. — Cactus as an adhesive with ferrous arsenate, 

 Brownsville, Tex., 1014- 



Date. 



Beetles 

 present. 



Living. 



Dead. 



Feeding. 



Not feed- 

 ing. 



Mar. 2 



4 

 4 

 4 

 4 

 4 

 4 

 4 

 4 

 4 



4 

 4 

 4 

 4 

 4 

 4 

 4 

 4 

 1 





 

 

 

 

 

 

 

 1 



1 





 3 

 3 

 3 

 2 

 3 

 2 

 1 



3 



Mar. 3 



4 



Mar. 4 



1 





1 



Mar. 6 



1 



Mar. 7 



2 



Mar. 8 



1 



Mar. 9 



2 



Mar. 10 



1 







It will be seen from the foregoing table that the mortality was 

 much too low to pay for applying the poison. It was observed that 

 the feeding was light for four or five days after confinement. The 

 solution did not adhere and distribute itself well enough to make a 

 good spray. 



About the same time that spraying was done on experiment No. 

 16 a second solution was made up, using the same amount of fer- 

 rous arsenate or 1 pound to 40 gallons of water. Eighty per cent 

 of the water used was taken from a tank where two days previous 

 1^ pounds of cactus to the gallon of water had been placed. This 

 made an exceedingly glutinous solution which caused the liquid to 

 spread uniformly as well as to adhere. On March 2 seven Diabrotica 

 balteata were placed on the plant. 



Table VIII. 



-Experiment No. 17. — Cactus as an adhesive with ferrous arsenate, 

 Brownsville, Tex., 1914. 



Date. 



Mar. 3. 

 Mar. 4. 

 Mar. 5. 

 Mar. 6. 

 Mar. 7 . 

 Mar. 8. 

 Mar. 9. 

 Mar. 13 

 Mar. 14 



Beetles 

 present. 



Living. 



Dead. 



Feeding. 



7 



6 



1 



3 



7 



6 



1 



6 



7 



6 



1 



6 



7 



6 



1 



4 



7 



6 



1 



5 



7 



6 



1 



4 



7 



6 



1 



3 



7 



5 



2 



1 



7 



5 



2 



4 



Not feed- 

 ing. 



