1919] ECONOMIC ZOOLOGY — ENTOMOLOGY. 549 



tory disturbances common in all three diseases. A comparison of the toxemia 

 observed in the Influenza epidemic with the toxemia observed In severe typhus 

 Indicates that influenza, like typhus, is essentially a blood Infection and not 



a primary respiratory infection. The toxemia observed in the last Influenza 

 epidemic was so severe that in many cases it caused death on the second or 

 third day after the onset. Attention is called to the fact that there are 

 localities in certain countries where influenza is endemic, as was found to be 

 the case in Russia in 1890 when investigated by the French Minister of Public- 

 Instruction. 



It is pointed out that the bedbug is quite universally distributed, and that 

 influenza may be transmitted by it is contended by the author. 



A list of 20 references to the literature is append* d. 



The periodical cicada or seventeen year locust, E. N. Cory (.lfrf. Col. AffT. 

 Ext. Serv. Bui. ll t (1918), pp. 11, figs. 10). — A brief popular account of the 

 periodical cicada which calls attention to the fact that it is due to occur in 

 the spring of 1919. 



Late dormant v. delayed dormant or green tip treatment for the control 

 of apple aphids, W. S. Regan (Massachusetts Bta. Hal. 18.' f (1918), pp. -$7-57).— 

 The results of comparative tests by the author, here reported, have been 

 summarized as follows : 



"The delayed dormant period is usually indicative of the complete hatching 

 of apple aphid eggs. At this time the buds have expanded from 0.25 to 0.5 in. 



" Lime-sulphur solution at full dormant season strength is less than 10 per 

 cent effective against the living aphids when applied at the delayed dormant 

 period. Lime-sulphur applied at the late dormant period, before the buds split 

 open and just before the hatching of the aphid eggs, appears to be highly 

 effective, under favorable conditions, in destroying the eggs, but the elements 

 of thoroughness of application and unfavorable meteorological conditions 

 present such uncertainty as to results that this treatment can hardly be recom- 

 mended as an effective control. If lime-sulphur is to be used as a control for 

 San Jos£ scale and no special treatment for apple aphids is to be made later, 

 best results against aphids, if present, are likely to be obtained by a late 

 dormant-season application just before the eggs hatch. Treatment at this 

 time should also be thoroughly effective against the scale. 



"The application of the lime-sulphur (1:6) and nicotin sulphate (1:800) 

 combination applied at the delayed dormant period gives practically a perfect 

 control for apple aphids, and makes unnecessary a separate earlier application 

 of lime-sulphur for San Jos6 scale. The percentage of efficiency will depend 

 mainly upon thoroughness of application. The ordinary dormant-season treat- 

 ment of apple orchards with miscible oil against San Jose scale, if applied 

 thoroughly at the delayed dormant period, should result in practically a per- 

 fect control of apple aphids also. 



"Delayed dormant applications of full dormant-season strength lime-sulphur, 

 lime-sulphur and nicotin sulphate combined, and miscible oils, if perfect, can 

 be made without material injury to apple foliage. Even when the foliage is 

 considerably more advanced, little severe injury usually results. This fact, if 

 taken into account, might make unnecessary separate applications for early 

 and late budding varieties. As the foliage becomes more advanced, however, 

 the success of the treatment involves greater difficulty, since the aphids are 

 very difficult to reach wheu they have the spreading leaves for protection. 



"The action of lime-sulphur in destroying both the aphid eggs and living 

 insects appears to be mainly mechanical, by sticking them to the twigs. The 

 action of nicotin sulphate in killing the living aphids is slow, requiring from 

 about half an hour to 24 hours or more for different individuals. Death 



