LITERATURE 259 



appear to be a potent factor in destroying large numbers of newly 

 emerged aphides : a temperature of 16-6° is said to totally inhibit 

 oviposition by the codling moth : in North America wet periods 

 during May and June tend to bring the pale western cutworm to 

 the surface of the soil and, by thus favouring its biological control, 

 is usually followed by a decreased infestation. It will thus be 

 evident how important it is to establish such correlations. Their 

 main desideratum is the accumulation of sufficient accurate 

 quantitative and qualitative data to enable the prediction of 

 insect outbreaks to be made with a degree of certainty that 

 would warrant the preparation, in advance, of appropriate control 

 measures. 



The collection of information of this kind is possibly best 

 organised and most advanced in Germany. In a paper by 

 Schnauer (1929) a very large amount of information, systematically 

 collected, year by year, through the auspices of the German 

 Agricultural Society since 1893, is summarised and analysed. 

 The causes of the outbreaks of major pests are surveyed in con- 

 junction with data respecting the chief meteorological factors. 

 The information thus accumulated has enabled it to be possible 

 to trace the probable connection of fluctuations in the prevalence 

 of specific pests with particular weather conditions. The data is 

 now being utilised as the basis for future forecasting. 



Literature 



Aeschner, 1932. Naturwiss., XX., 50. 



1934. Parasitology, XXV., 309. 



and RiES, 1933. Zeits. Morph. Okol. Tiere, XXVI., 529. 

 Alpator and Pearl, 1929. Amer. Nat., LXIIL, 37. 

 Back and Cotton, 1925. Journ. Agric. Res., XI., 1035. 



and Pemberton, 1918. U.S. Dept. Agric, Bull. 640. 

 Bacot and Harden, 1922. Biochem. Journ., XVI., 148. 

 Barber, 1929. U.S. Dept. Agric, Circ 71. ^ 



Belehradek, 1935. " Temperature and Living Matter." Berlin. 

 Berland, 1934. Soc Biolgeog., Mem. 4, 155. 

 Berlese, 1906. Redia, III., 8. 

 Bodenheimer, 1927. Zeits. angew. Ent., XII., 89. 

 Bodine, 1925. Journ. Exp. Zool., XLIL, 91. 

 Brues, 1927. Quart. Rev. Biol., II., 181. 



and Glaser, 1921. Biol. Bull., XL., 299. 

 Buchner, 1921. " Tier und Pflanze in intrazellular Symbiose." Berlin. 



1928. " Holznahrung und Symbiose." Berlin. 



