256 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



Antonio de UUoa to Piura in the year 1740, mentioning the cultivation 

 of cotton in the small fields here at that time. This shows that cotton 

 has been cultivated more or less in the Department of Piura for cen- 

 turies, but only on a small scale until 1864. Thus there is no telling 

 how long ago the weevil found its way from the humid Ecuadorian 

 coast region into the semi-arid districts of Piura and the coast strip 

 of Peru farther south. 



THE WORK IN PERU AGAINST THE WHITE SCALE OF 



COTTON 



By Charles H. T. Townsend, Piura, Peru 



Hemichionas'pis minor, commonly known in Peru as the piojo 

 bianco, has within a few years past developed into a serious pest of 

 cotton in the Department of Piura in northwestern Peru. This insect, 

 if we include its close allies, is nearly tropicopolitan and its country 

 of origin is a matter of much doubt. Whatever country may have 

 been its original home, it is now quite certain that, like the square- 

 weevil, it reached Peru from the humid coast region of Ecuador, 

 where it occurs on wild cotton at the present time. 



It was first noted in Peru in May, 1905, on cotton in the valley of 

 the Rio Piura for a couple of miles along the river in the immediate 

 neighborhood of the town of Piura, notably at Coscomba and Mira- 

 flores. It was not noted in the Rio Chira valley to the north of Piura 

 until the second year following, in 1907, and did not reach Somate 

 in the upper limits of the large cotton districts of the Chira until 1908. 



At the time of my arrival in Peru, in November, 1909, it was well 

 distributed throughout the large cotton haciendas of the Rio Chira, 

 and those of the upper half of the Rio Piura, but had not spread farther 

 south in the latter than the vicinity of Casa Grande. In February, 

 1910, it was first noted at Santa Clara just to the south of the last- 

 named point, and during that year it appeared scatteringly throughout 

 the lower Piura valley, reaching the vicinity of Sechura which is near 

 the sea. The present year it has appeared quite uniformly through- 

 out this newly invaded district, and thus now holds the entire cotton 

 region of Piura Department in force. It is yet unknown in the cotton 

 districts farther south in Peru. 



In this part of Peru, namely the northern coast region, the wind 

 blows always from the south and is usually strong and long-continued. 

 The scale has been spread through the Chira and Piura districts by 

 two agencies acting in contrary directions. The winds have carried 

 it northward up the -rivers. The waters of the two rivers, flowing 



