PORTO RICO AGRICULTURAL EXPERIMENT STATION. 
[Under the supervision of A. C. True, Director of the States Relations Service, United 
States Department of Agriculture.] 
E. W. Axlen, Chief of Office of Experiment Stations. 
Walter H. Evans, Chief of Division of Insular Stations, Office of Experiment 
Stations. 
STATION STAFF. 
D. W. Mat, Agroyiomist in Charge. 
P. L. Gile, Chemist. 
C. F. Kinman, Horticulturist. 
R. H. Van Zwaluwenbukg, Entomologist. 
E. W. Brandes, 1 Plant Pathologist. 
H. C. Henricksen, Assistant in Extension Work. 
W. A. Mace, Assistant in Extension Work. 
T. B. McClelland, Assistant Horticulturist. 
J. O. Carrero, Assistant Chemist. 
H. E. Thomas, Assistant Plant Pathologist. 
W. P. Snyder, Assistant in Plant Breeding. 
C. Alemar, Jr., Clerk. 
LETTER OF TRANSMITTAL. 
Porto Rico Agricultural Experiment Station, 
Mayaguez, P. R., March 20, 1917. 
Sir : I have the honor to tranmit herewith a manuscript by R. H. Van Zwalu- 
wenburg, entomologist of the station, on the Changa or West Indian Mole 
Cricket. The changa or mole cricket, by far the most destructive insect known 
to the agriculturist in Porto Rico, causes enormous losses justifying the long 
series of investigations made of its life history and methods of control. This 
bulletin, which is the second publication by the station on the changa, carries 
the "investigations much further than the first. It is not intended as final, how- 
ever, as efforts will be continued to find more effective means of control, such 
as the discovery and introduction of natural checks. 
I recommend that the manuscript be published as Bulletin No. 23 of this 
station. 
Respectfully, 
D. W. Mat, 
Agronomist in Charge. 
Dr. A. C. True, 
Director States Relations Service, 
United States Department of Agriculture, Washington, D. C, 
Recommended for publication. 
A. C. True, Director. 
Publication authorized. 
D. F. Houston, 
Secretary of Agriculture. 
1 On leave. 
(2) 
