SOUTH AFRICAN BAGWORMS. 639^ 



District of the Northern Transvaal, and its occurrence in 

 South Africa is probably co-extensive Avith that of its original 

 food-plants, the native thorn-bushes, consisting of various 

 species of Acacia and Mimosa. In Natal it is the Bag- 

 worm par excellence, and it has become notorious during 

 the last decade as one of the worst pests of the Black Wattle 

 plantations. What was merely an " entomological curiosity " 

 some fifteen years ago has evolved into a pest of prime 

 economic importance within the last few years, seriously 

 threatening the Black Wattle industry in Natal. So extensive 

 became its spread, and so serious its injury to the wattles^ 

 that it was realised necessary to make this insect (with other 

 wattle pests) the subject of a special investigation by the 

 Department of Agriculture. Our work on this and the 

 numerous other species of insects injurious to the Black 

 Wattle (Acacia mollissima Wild.) has now been in pro- 

 gress for about three years, and, while studj'ing the Wattle 

 Bagworm primarily from an economic standpoint, many other 

 matters of interest concerning the biology of the species have 

 been observed, which appear not to have been recorded 

 before. 



(1) Literature. 



The insect has been known in the wattle plantations for a 

 great many years, and as early as 1889 it was noticed by the 

 then Natal Entomologist, Claude Fuller ; but, though wide- 

 spread, it did not appear to cause any appreciable injury and 

 was not considered of economic importance. 



In 1899 Claude Fuller published the first more or less 

 detailed account of the life-history of this insect in his Annual 

 Report for that year, where we find three pages devoted to it. 

 In 1909 the same author published an account of this bag- 

 worm and some half-dozen others as Bulletin No. XVI of the 

 Natal Department of Agriculture, in Avhich he devoted some- 

 seven pages to the life-history of the Wattle Bagworm. 

 Owing to the outbreak of 1911-12 in the New Hanover area,, 

 another, more detailed investigation of the Wattle Bagworm 



