45° MAIZE 



CHAP, larvae would be injured, and thus destroyed. If the ground 

 could be kept under constant cultivation, by adopting a system 

 of rotation and the ploughing-in of green manure, so as to pre- 

 serve its fertility, in place of exhausting it by constant cropping 

 for a term of years and then letting it lie fallow for a time to 

 recuperate — as is done in the present system — I believe injury 

 from this pest would be almost entirely avoided. Cultivated 

 lands apparently do not attract the beetles, and they therefore 

 take to the native veld to deposit their eggs. But before we 

 can hope to induce the farmers to go in for a system of rota- 

 tion in place of the present practice of long fallowing, it will 

 be necessary to show by means of demonstration farms that 

 the intensive cultivation necessary to make rotation answer 

 will pay them better than the present system of extensive 

 cultivation. I am satisfied myself that an intensive rotation 

 would be much more profitable than the present system, and 

 would combine numerous other advantages — not the least of 

 which will be the fact that it will open the way for a much 

 larger farming population." 



418. Plant-lice {Aphides). — Aphis or green-fly is commonly 

 found on the maize tassels in some seasons, but does not ap- 

 pear to cause serious damage. A common opinion is that 

 prevalence of green-fly coincides with drought ; the writer has 

 noticed, however, that in some seasons (e.g. February, 191 3) 

 it was abundant during a time of plentiful rains. 



419. Rose-cliafers. — Some species of Rose-chafer, notably 

 Porphyronota hebrce and Plcesiorhina plana? feed on the male 

 flowers of the maize plant, probably on account of the pollen. 

 These two chafers are particularly troublesome in eating holes 

 in paper bags used for the collection of pollen in maize-breeding, 

 the pollen escaping through these holes ; from three to a dozen 

 chafers will be found in one bag. They do not appear to 

 injure the maize plant. 



The common hive bee, Apis mellifera, also visits the tassels 

 of the maize plant for the purpose of collecting pollen ; on this 

 account it is popularly supposed to effect cross-pollination, but 

 during an extended series of observations the writer has never 

 seen a bee carry pollen to, or even visit, the maize-silks, so that 

 it is not at all probable that it is a factor in cross-pollination. 



Weevils and grain-moths are dealt with in chapter XI. 



1 Both kindly identified by Dr. L. Peringuey, Director of the South African 

 Museum, Cape Town. 



