38 



PAPERS ON INSECTS AFFECTING VEGETABLES. 



and confined in cages. No parasites were obtained, nor were pre- 

 daceous enemies observed in the field. In one or two so-called stock 

 cages in the insectary, which were crowded with surplus webworms 

 and neglected, a disease or " wilt " developed which killed many 

 larva?. This " wilt " did not occur in the regular cages and was not 

 observed in the field. Apparently, as far as Hawaii is concerned, this 

 webworm seems to be remarkably free from natural enemies. 



Fig. 7. — Small compressed-air sprayer, fitted with extension rod, elbow, and Vermorel 



type nozzle. (Original.) 



EXPERIMENTS WITH INSECTICIDES. 



During the fall of 1910 some experiments were made against this 

 webworm. All experiments with insecticides were conducted on in- 

 fested cabbage in a garden at Honolulu. In all cases the insecti- 

 cides were applied with a small compressed-air sprayer (fig. 7), 

 which was fitted with a short extension rod, elbow, and a small 

 nozzle of the Vermorel type. The experiments were as follows: 



Experiment No. 1. — Paris green, 2 pounds, and whale-oil soap, 8 

 pounds, in 100 frallons of water. 



