New York Agricultural Experiment Station. 379 



M. Weed: 16 " In the village of Newfields, N. H., the improvement 

 society offered the school children 10 cents a hundred for all the 

 egg masses, or caterpillar belts, as they are locally called, that they 

 would bring in. Many of the children worked faithfully, and 

 when in February I was called to point the moral of the process I 

 found that 8,250 egg masses had been obtained." Allowing 150 

 eggs to each egg mass, there were 1,237,500 eggs destroyed for an 

 expenditure of $8.25. Taking into consideration the injury which 

 the caterpillars from so many eggs are capable of doing it will be 

 seen that the investment was a mere trifle compared with the good 

 accomplished. 



Destroying the caterpillars. — The methods of destroying the 

 caterpillars may be grouped under two heads, as follows: Spray- 

 ing the infested trees with an arsenical poison and destroying the 

 caterpillars in any convenient way while in the nests. 



Spraying. — Like other caterpillars which devour the leaves this 

 species is susceptible to arsenical poison. Orchards that are sys- 

 tematically sprayed with pure Paris green or other arsenical sel- 

 dom suffer serious injury from the attacks of this insect. 



Experiments. — In connection with the spraying experiments 

 against the canker worm as shown on page 385 of this Report, the 

 effect of the poison was observed on the caterpillars from a num- 

 ber of nests. The experiments were conducted in an apple 

 orchard at Rushville, N. Y., owned by Mr. O. L. Jackson. 



Objects of the experiments. — Many requests have come to us for 

 information concerning the effects of arsenical poisons upon the 

 tent caterpillar. While it is usually more practical to destroy the 

 caterpillars in the nests it is sometimes desirable to know whether 

 spraying with arsenical poisons will check them. It was the 

 object of these experiments to throw some light upon the subject. 



Experiments in 1897. Green arsenite. — The green arsenite 

 was used at the rate of 1 pound to 150 gallons of lime water. 



16 Notes on The Tent' Caterpillar, U. S. Dept. Agr., Div. Ent., Bui., 17 n. ser., 

 pp. 76-78. i 



