318 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



the life cycle of lanigera in United States is circumstantial evidence 

 strong enough to serve as a working hypothesis and this question will 

 doubtless be settled by European workers in due time.^ 



A BRIEF REPORT ON THE PIOJO BLANCO OF COTTON 



By Charles H. T. Townsend, Lima, Peru 



Arrival and Spread 



This scale-insect, technically known as Hemichionaspis minor, 

 has developed since 1905 into a serious pest of cotton in the Depart- 

 ment of Piura. The species is more or less tropicopolitan and its 

 country of origin is in doubt, but it seems ciuite certain now that 

 it reached Peru from the humid coast region of Ecuador where it 

 occurs on wild cotton at the present time. It evidenth' entered 

 the Piura region at the port of Paita on shipments of plants from 

 Guayaquil or Tumbes, and was thence carried in shipments by rail 

 to the towns of Sullana and Piura. At these two places it estab- 

 lished itself in the gardens and cotton patches near bj-, thus gaining 

 a foothold. 



It first attracted attention on cotton in the Piura valley near Piura 

 town, in May, 1905, but was not noted as a pest of cotton in the 

 Chira vallej' until 1907, and reached the upper cotton districts of 

 the Chira around Somate in 1908. It was not noted on cotton in 

 the southern districts of the Piura valley until 1910, having appeared 

 at Santa Clara in February of that year. During 1910 it spread 

 scatteringly southward from Santa Clara to near Sechura, thus 

 completing the invasion of the entire cotton area of Piura Depart- 

 ment in the Piura and Chira valleys. It reached the extreme upper 

 cotton districts of the Piura valley, at Solsol, Paccha and Nomala 

 in 1910; and was found by me in November, 1910, heavily infesting 

 old tree-cotton at Macara, Ecuador, and on cotton as far up the 

 Rio Macara as a point above the Hda. Limon Crossing. 



The scale has been spread through the cotton districts of the Chira 

 and Piura valleys by two agencies operating in contrary directions. 

 The strong and long-continued winds from the south have carried 



iSince this paper went to press two marked publications from Germany have been 

 received; one written by Dr. Carl Bonier {Kaiserliche Biologische Anstalt fur Land — 

 und Forstivirtschaft, August, 1909) in which he suggests the probable necessity of a 

 host plant other "than the apple for the winter egg, stem mother, and the spring gen- 

 eration of the " Blutlaus, " and the second by Dr. L. Reh, Hamburg, who, (Der 

 Praktische Ratgeher im Obsl- und Gartenbau. February 2, 1913, pp. 47-48), reviews 

 both German and American observations on the "Blutlaus" and reinforces Doctor 

 Borner's conclusions on the basis of his own fruitless searches of many years for the 

 winter eggs of this aphid on apple. 



