224 JouiiKAL OF THE jDei'artmejv'i oe AuKicuLTUKE. — Sept., 1922. 



more assistance if the rains had come earlier. In some districts, by 

 the time good rains fell and the voetgang-ers had hatched out the 

 birds had gone north again. 



Flies. — The large grey fly (Wohlfahrtia brunispalpis) , which 

 deposits its maggot on the back of the locust, was prevalent during 

 last season amongst the locusts, especially in the western Karroo, 

 Bushmanland, Kenhardt, Prieska, Calvinia, Carnarvon, and Fraser- 

 burg Districts, where it attacked and destroyed large swarms of flying 

 locusts, also voetgaDgers in the last stage. In Bushmanland, on the 

 border of Kenhardt-Calvinia and Namaqualand, this fly was in such 

 numbers that it became a nuisance to the population. In Bechuana- 

 land single specimens were noticed in April, and it is hoped that 



Flying Swarm. 



these will increase in number during next suninier and help to eradi- 

 cate the locusts. 



Recently a small black fly (at present unnamed) has been observed 

 depositing its eggs on the egg-pockets of locusts. Near Graaff-Reinet 

 this fly was seen walking amongst a swarm of locusts which were 

 busy digging holes in the ground in which to deposit their eggs. This 

 fly is quite tame and can easily be caught, probably because it becomes 

 accustomed to the commotion caused by the locusts fluttering their 

 wings when they are laying eggs. Immediately the female locust 

 extracts its body from the hole in the ground, i.e. before the spume 

 which nature provides for sealing up the egg-pocket, has had time to 

 harden, this fly creeps into the cavity. After satisfying itself that 

 eggs have been deposited it emerges and goes in again backwards, 



