JOURNAL 



OF 



ECONOMIC ENTOMOLOGY 



OFFICIAL ORGAN AMERICAN ASSOCIATION OF ECONOMIC ENTOMOLOGISTS 



Vol. 15 OCTOBER, 1922 No. 5 



ANT CONTROL ON SHIP BOARD 



By W. T. Clarke, Professor Agricultural Extension, University of California 



Early in December, 1921, the Pacific Mail Steamship Company asked 

 for help in the control of ants infesting certain of their passenger ships. 

 This Company runs a line of vessels to and through the Panama Canal 

 and thence northward to Havana, Cuba, and to Atlantic seaboard points 

 in the United States. The ants were said to be very troublesome on the 

 ships of this line. They not only caused a considerable pecuniary loss in 

 the destruction of food stiiffs but attacked passengers and crew. Their 

 bite was reported to be very painful, causing a local swelling and inflam- 

 mation with much itching. The situation as reported was worthy of 

 careful study to develop control measures and the writer took up th^ 

 study. 



A careful search of the literature on ants failed to disclose any report 

 of these creatures having been made on ship board and the problem 

 developed, for this reason, into an entirely new study aided, to be sure, 

 by the successful control measures used on shore. It was finally decided 

 that to do the problem some degree of justice the study should extend 

 through an entire voyage of one of the Company's ships. The ship 

 chosen was the Colombia due to sail from San Francisco December 12, 

 1921, on its twenty-second voyage, outward destination being Baltimore, 

 Maryland. Before the ship sailed a careful inspection was made and no 

 ants found. As the weather was quite cold at the time, thepresimnption 

 was made that the ants were dormant. Officers and members of the 

 crew who had been on the Colombia on the previous voyage were 

 unanimous in stating that the ants had been present in overwhelming 



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