70 PKESIDEXTIAL ADDRESS SECTION ]). 



acid for the destiiiction ot lice and bedbug's. The State owes 

 it to itself as well as to the poor people concerned to see that 

 such an easy means of control is adopted. 



AuiniaJ Diseases: . 



Animal diseases such as East Coast Fever, nagana and 

 horse sickness — especially tlie latter, wliich for over a quarter 

 of a century has baffled every effort to determine its natural 

 transmission — serve to illustrate the need for research alono- 

 that line. 



Ageicultural Pests. 

 Maize Insects. 



While reviewing- the subject of maize insects recently, 

 I was impressed with the fact that prior to 1900 comparatively 

 little interest was taken in the pests that attack maize. The 

 only explanation that I can sugg-est is that maize did not always 

 hold its present important position in South Africa. 



Twenty-five years ago, for example, there was no export 

 trade in maize, and hence the supply no doubt often exceeded 

 the demand. TTnder those circumstances insect injury would 

 be passed over as of little consequence. The live stock 

 industry, which now makes heavy demands on the maize 

 crop, was languishing- under tlie burden of rinderpest, lung- 

 sickness, horse sickness, sheep scab and tick-borne diseases— 

 redwater, heartwater, East Coast Fever. Locusts made 

 periodic inroads, and on account of their spectacular nature 

 attracted i)()pular attention everywhere. In fruit-growing 

 districts and in the towns the Australian bug (Iceri/a 2nirchasi) 

 caused a great outcry, and the grape Phylloxera even brought 

 about a change of Government. In the midst of plagues that 

 caused such violent political as well as economic upheavals, 

 the insect pests of maize must have seemed such modest 

 creatures that they were passed by as not worth notice. 



Vahie of Maize in S^outli Africa. — Some idea of tlie value 

 of the maize crop in South Africa can be gained from tlie 

 following' official Crop Report Estimates : — 



The total vield for the nine (9) years was 



therefore \ 81,898.716 muids. 



ond the total value, at 9s. ])er niuid, was £86,854,422. 



The average annual vield was 9.099,857 muids. Avliicli, 

 at 9s. permuid, amounted to £4,094,935. 



