288 ECONOMIC ENTOMOLOGY IN MOCAMbIqUE. 



the State tens of thousands of pounds to control, besides endan- 

 gering the cotton industry of the whole of South Africa. Its 

 mtcrception was the more fortunate because, in a recent trip 

 through the cotton fields of the northern disti-icts, no indications 

 were found of the presence of the pink boll worm, so that there 

 is a great probability that this Province, besides the Union of 

 South Africa, is one of the few countries in which this scourge 

 has not yet become established. 



Entomologic-^l Problems of this Province. 



Having thus secured ourselves against introduction of agricul- 

 tural pests from outside, a start can be made with the study of 

 the insects, injurious and beneficial, of this country. We find 

 that, entomo logically, this Province is practically terra incognita. 

 I do not mean only from a collector's point of view, in regard to 

 which this would be an extremely interesting field, but also from 

 the point of the economic entomologist, the insects either actually 

 injurious or potentially so are very varied and different from those 

 met with in other parts of South Africa. As an illustration I may 

 mention that, while in the cotton fields of the Union the greatest 

 enemies of the cotton plant appear to be various leaf -eating larvae 

 of Noctuidae, we find here in our northern Provinces, although 

 these just-mentioned pests are present in considerable numbers, 

 the greatest amount of damage is inflicted by three small stem- 

 boring beetles of the family Curculionidae, namely, Apion con- 

 strictiim (Hartmann), A])ion consimilc (Wagner), and Apion 

 considerandinn (Fhs). Similar species have been reported from 

 Tanganyika territory, but, from the accounts given, were not 

 sufficiently numerous to cause apprehension. In our northern 

 districts, however, we have seen stretches of a hundred hectares 

 and more totally ruined by these insects. Again, while the cotton 

 stainers of the genus Dysdercus are present, as elsewhere, we 

 found that in some localities their place was taken by an entirel}' 

 different species, CaJUdea drcgci, and in those places the 

 Dysdercus were conspicuously absent. 



In the sugar plantations we have found the adults of a certain 

 root-feeding Scarabaeid, as yet imdetermined, present in 

 enormous numbers. Although we have not yet had time or 

 opportunity to make a study of this insect, the experience in 

 other sugar-growing countries with insects of the same group — I 

 only need refer to the fight against Phytahis smithi in ^Mauritius 

 and the efforts made in tlie West Indies to control the various 

 species of " hard backs " — is sufficient to cause ue great appre- 

 hension in regard to the injury which may be caused by this 

 species here. Again, the presence of enormous numbers of 

 various species of Bostrychidae. for the greater part not previously 

 reported from this locality, and of Platypodidae, which were 

 nearly all new to science, was an unwelcome sign of potential 

 future injm-y. Considering that these small species are all wood 

 ])orers, and that some have been known to attack standing cane, 

 it is evident that this matter calls for thorough investigation at 

 the earliest possible date. 



