BUIIEAU OF ENTOMOLOGY. 329 



cases have been investigated. The conditions surrounding the latter 

 indicate that the insect Avas present in small numbers and vigorous 

 means were immediately taken by the New York department of agri- 

 culture and the superintendent of parks of Brooklyn, X. Y., to eradi- 

 cate it. This work was supplemented by a small amount of scouting 

 work carried on by this bureau. Further scouting should be done 

 durino- the winter, and if no extension of the colonv is found it should 

 be possible to exterminate the insect in this locality within a rea- 

 sonable time. 



Xhe New Jersey colony of the gipsy moth proved to be one of long- 

 standing, and the situation is complicated by the fact that large 

 numbers of shipments of trees have been made from and near the 

 colony to many destinations. A record of all shipments has been 

 secured, which shows that stock has gone to 14 different States besides 

 New .Terse}'. These shipments are being traced as rapidly as possible, 

 and already two infestations in New Jersey, one in Pennsjdvania, and 

 one in New York have been located. 



Preliminary scouting work by employees of this bureau has shown 

 that the infestation at Somerville occurs in an area of about 100 

 square miles. The area will probably be increased later, when effec- 

 tive scouting can be done after the leaves are off the trees. The gipsy 

 moth situation, both in New England and elsewhere, is extremely 

 serious at the present time. Sufficient funds are not available to 

 carry on the work effectively, and unless more very thorough work 

 is done the insect is bound to spread rapidly. 



The very high cost of supplies and equipment, together with the 

 high price and scarcity of labor, further complicates the successful 

 handling of this problem. Unless adequate funds can be secured 

 to meet this emergency, there is little possibility of preventing the 

 spread of this insect or keeping it within reasonable bounds. 



SOUTHERN FIELD-CROP INSECT INVESTIGATIONS. 



Investigations of southern field-crop insects have been continued 

 under the direction of Dr. W. D. Hunter. 



CoTTOx INSECTS. — Owiug to rapid development in the studies of 

 boll-weevil poisoning, the work at the Delta laboratory at Tallulah, 

 La., for the fiscal year has been largely limited to different phases of 

 this particular problem. Practical control work conducted in co- 

 operation with cotton planters was extended to include more than 

 50,000 acres of cotton during the growing season of 1919, and was 

 further expanded in the spring of 1920. Kesults on the whole have 

 been very satisfactory, and have served as a basis for numerous circu- 

 lars of advice which have been issued for*the benefit of farmers under- 

 taking commercial poisoning work. This method of control has 

 spread very rapidly. During 1918 poisoning was practically confined 

 to the properties under the supervision of the experts from the Delta 

 labcjratory. In 1919 the farmers themselves took it up, and during 

 the season approximately 3,000,000 pounds of calcium arsenate were 

 used. The results were so good that in 1920 the demand for this 

 chemical vras greatly increased, and, while no accurate figures are 

 available, the total amount of calcium arsenate sold for use this year 

 surely exceeds 10,000,000 pounds. 



24435— AGB 1920 — 22 



