218 



The chief pests of maize in South Africa are cutworms, Heliothis 

 {Chloridea) obsolcta (ear worm), Heteronychus arator (black beetle), 

 StropJiosomns amplicollis (snout beetle) and Busseola fusca, the last- 

 named being undoubtedly the most serious of these. 



The results of field observations show that B. fusca is neither two 

 nor three brooded, but a combination of both ; should the moths 

 emerge early in the spring, three generations may occur, but the moths 

 of the third brood will in consequence appear later in the following spring 

 and thus only two broods will occur in that year. Oviposition occurs 

 from the end of October to the end of December according to conditions 

 and locality. The eggs hatch in from 8 to 10 days, and the larval period 

 varies from 30 to 50 days. Pupae of the first spring brood occur from 

 the end of December to January, and adults emerging from them 

 oviposit from the end of January to the first week in February on 

 maturing plants. The larvae reach maturity during March and 

 April. Some of these pupate and emerge as moths, giving rise to a 

 partial third generation. The larvae of these and the remainder of 

 the second brood hibernate in the remains of the plant. 



The natural enemies include the pupal parasite, Exephanes nigro- 

 maculatus, Cam., which is probably widely distributed in South Africa, 

 but does not control the insect ; the larval parasites, Br aeon sesamiae. 

 Cam., and Stenopleura { Apanteles) sesamiae. Cam.; and the ants, 

 Iridomyrmex humilis and Dorylus helvolus. Diopsis apicalis, Dalm., 

 has been associated with B. fusca, but this fly is probably attracted to 

 maize stalks by the decay induced by the borer. 



No methods are known whereby any of the natural enemies can be 

 utilised effectively, the only reliable remedial measures being cultural 

 and other operations that directly destro}^ the insect or deprive it of 

 food and shelter. The most suitable line of action must be decided 

 according to local conditions [loc. cit.]. 



McCarthy (T.). Insects attacking Nut Kernels. — Agric. Gaz. N.S.W., 

 Sydney, xxxii, no. 1, 3rd January 1921, p. 9. 



Plodia inter punctella (Indian meal moth), Tribolium castaneum 

 {ferruginemn) (rust-red flour beetle), Silvanus surinamensis (saw-toothed 

 grain beetle) and Trogosita mauritanicus (cadelle beetle), are the most 

 common species attacking various kinds of nuts, especially when un- 

 shelled. Infestation occurs most frequently in storage in the country of 

 origin, but may also occur as the result of contact with other infested 

 foodstuffs during transit. 



Froggatt (W. W.). " Khapra," an Indian Wheat Pest. — Agric. Gaz. 

 N.S.W., Sydney, xxxii, no. 1, 3rd January 1921, pp. 21-23. 



The opinions of previous authors as to the economic importance of 

 the Dermestid, Trogoderma khapra, are briefly reviewed [R.A.E., 

 A, V, 126, 359]. This beetle is most injurious to wheat in India during 

 the hottest and driest part of the summer. Owing to the different 

 climatic conditions in Australia, it is thought that the damage caused by 

 T. khapra would be less than that caused by weevils in the event of it 

 being accidentally introduced. 



