210 C. B. HARDENBERG. 



these two natural agencies are entirely sufficient to check 

 any undue increase of the species. 



This bagworm seems to be extremely local in its distribution. 

 While one tree may be heavily infested^ other trees in the 

 neighbourhood may entirely escape. It seems that the young, 

 upon hatching, do not travel far. We first found this bag- 

 worm on a single tree adjacent to the Natal Museum, while 

 the other neighbouring trees were free. When returning to 

 Pietermaritzburg the next season I found that the tree had 

 been cut down, and, to my surprise, I was not able to find the 

 insect on any other tree, although oaks are fairly common in 

 the town. At last I was fortunate enough to find a number 

 of specimens on a single small tree, while other oaks sur- 

 rounding the infested one were quite free from them. 



The method by which this species is distributed has not 

 been ascertained, but from the peculiarities of its distribution, 

 as noted above, we may assume that the wind-dispersal of 

 the young does not play such an important part as in the case 

 of the Wattle Bagworm, although it may assist to some 

 extent. The three methods which might be conceived to 

 bring about this distribution are : 



(a) Distribution of the Young Bag worms by the 

 Wind. — We have observed no pronounced phototropism in 

 a brood of newly-hatched young of this species like that seen 

 in A. junodi, and accordingly the young would not travel to 

 the top of the tree so as to be taken up by the wind. This 

 method is also not very probable, since we have invariably 

 found that the lower branches of the tree are most heavily 

 infested, which would suggest that the infestation starts from 

 below. 



It must be mentioned that both trees on which the bag- 

 worms were found were not in vigorous health, and perhaps 

 the physiological condition of the trees may have an important 

 influence on the distribution of the insect. 



(b) Distribution of the Mature Bags by the Wind. 

 — As the bags for pupation are attached to the midrib of the 

 leaf, they will di*op to the ground and be blown about by the 



