294 SCIENCE IN AFRICA 



under the Tobacco Pests Suppression Act, 1933, and a whole- 

 time inspector is employed for this purpose. 



In Southern Rhodesia, also, maize is subject to serious attack 

 by the rice-weevil [Calandra oryzae L.) which appears to find both 

 the climate of the colony and the flat white type of maize grown 

 particularly favourable to its development. An entomologist has 

 been detailed to carry out research of a fundamental type on the 

 ecology of this pest and its relation to present methods of handling, 

 storage, and exporting (Jack 1935b). 



With reference to quite a diflferent class of products, hides and 

 skins, when stored in warm climates even for short periods, are very 

 liable to attack from the skin beetle, Dermestes vulpinus. This pest 

 was the cause of such loss, particularly in South Africa, that a 

 special investigation was carried out by Smit (1934a) at Port 

 Elizabeth into the means of protection. His conclusions show that 

 salt and arsenite of soda, when properly applied, give complete 

 protection, so that control of the pest is largely a matter of ade- 

 quate attention in preparing the skins. 



In all control of insects by fumigation and similar means, recent 

 work on insect diapause (i.e. the period of life history when activity 

 is temporarily suspended) is of the utmost importance, since 

 insects are much more resistant to poisons at that time. Apart 

 from the obvious diapause of pupation in the higher insects, it is 

 now recognized that other less noticeable periods occur at various 

 stages in the life history for reasons which are often obscure. This 

 may necessitate much long-range research before control can be 

 effective. 



INSECTS AND TICKS IN RELATION TO DISEASE 



The difficulties of medical and agricultural entomologists are 

 essentially the same in so far as they depend on the circumstances 

 and the people with which they have to deal. Most of the larger 

 territories have entomologists attached to the medical depart- 

 ments, and some have also veterinary entomologists as well, but in 

 others the same entomologists are responsible for agricultural, 

 medical, and veterinary work. 



The following brief account does not include references to the 

 fundamental research which has revealed the causes of principal 



