244 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



The destruction of the hibernating "flies" is an important measure 

 for the protection of pear orchards from psylla attacks. Careful 

 spraying in the spring greatly reduces the numbers of the individuals 

 and in some instances has completely freed plantings from the insects. 

 The activity of the adults at that time has, however, prevented some 

 growers from obtaining full control of this pest. It appears from the 

 work that we have done that, on account of the difference in the be- 

 havior of the "flies" to gradually lessening temperatures, more favora- 

 ble conditions exist in the late autumn for effective spraying. 



During 1911 unprecedented num^bers of psyllas entered hibernation, 

 which afforded an excellent opportunity for demonstrating the value 

 of fall treatments for the "flies." The experiments commenced on 

 December 6 and continued until December 18, during which period 

 thousands of the insects were clustered on the branches of the trees. 

 The sprays applied were nicotine, fish-oil soap and lime-sulphur solu- 

 tion, used either separately or in combination. Nicotine preparations 

 and soapy solutions were ver^- effective. The lime-sulphur solution at 

 dormant strength did not cause a marked reduction in the numbers 

 of the psyllas, but with the addition of nicotine, the results from the 

 combination compared favorably with the soapy sprays. Less than 

 five per cent of the original infestation remained in the orchard at the 

 completion of the work and in the following spring only scattering 

 " flies " appeared upon the trees. In 1912 orchardists who were usually 

 unable to control them by spring treatments found little difficulty in 

 ridding their orchard of the insects through late fall applications of 

 these sprays. 



The success attending the fall spraying of pear orchards for the psylla 

 is dependent upon, — (1) an understanding of weather influences upon 

 the activities of the hibernating adults; (2) the complete wetting of 

 each tree as the work proceeds; (3) thorough work in spraying. 



THE 1912 OUTBREAK OF ALABAMA ARGILLACEA IN PERU 



By Charles H. T. Townsend, Lima, Peru 



During the first few months of 1912 the cotton leaf-caterpillar 

 multiplied in extraordinary numbers in the cotton districts of the 

 Peruvian coast region from about 9° to nearly 12° south latitude, and 

 more or less unusually and generally to the northward as far as Piura 

 Department. Complete defoliation occurred over the greater part of 

 the districts from Chancay to Casma, reaching the latter valley on 

 March 5. Much interest attaches to this outbreak from the fact that 

 the meteorological conditions of the warm season of 1911-1912 in the 

 coast region of Peru were very unusual. 



