A Fearless Fly that Defies the Driver-Ant, 



169 



Pholo b^•^ 



Worker Driver-Ants. 



[H. Baslin. 



Two of the wingless worker caste are shown on tlie same 

 scale of magnification as the male below — twice the size 

 of nature — in order to show the great disparity of size in 

 the same species, which is distinguished as the black 

 driver-ant. 



flv before them ; from the cockroach and the 

 mouse to the huge python, the elephant, the 

 gorilla, and the warlike native man, the stor}' 

 is the same. The driver-ant has got its name 

 because it is the most fitting term to use : it 

 actually drives all creatures before it, and 

 tliose that lag or fall b\- the way are consumed 

 by the ants. 



In all the records and observations of 

 naturalists and travellers in Africa there is 

 little said on the other side — of any defiance of 

 the all-conquering drivers by other creatures. 

 But quite recently Mr. W. A. Lamborn, in 

 Southern Nigeria, has recorded his observations 

 of the manner in wliich an insignificant fly, about the size of our common 

 bluebottle, openlv deprives the driver of its most jealously guarded treasure — 

 the chrysalids that should develop into mature ants. It was not an 

 accidental or isolated instance of the fly coming across a column of drivers 

 and picking up something, for all the circumstances narrated by ^Ir. Lamborn 

 show that so many of the same species of fly ^ were similarly engaged in this method 

 of obtaining food that it must be habitual with them. Having noted this strange 

 behaviour of the flies without fully understanding it, he set himself to discover what 

 business connection they could have with such powerful Insects. So recently as 

 November 8th, 1913, he wrote to Professor Poulton, saying : " I succeeded to-day 

 in solving the problem between the flies mentioned in my letter of October 12th 

 and the black driver-ants.- A column of drivers was crossing a conduit over a 

 stream, following precisely the same ant-path that I have seen them traverse 

 several times before. . . . 

 I soon saw three or 

 four of the flies flying 

 about the moving column 

 and occasionally settling 

 near it, sometimes on the 

 ground quite close to the 

 ants, sometimes on a 

 blade of grass, stone, or 

 other raised object. Such 

 as settled on the groimd 

 were extremely alert, and 

 being able to run rapidly, 

 never allowed anv ants to 

 approach anv nearer 

 to them than about a 

 quarter of an inch. When, 

 as frequently happened, 



I'liolo by] 



Winged Driver-Ant. 



[H. Bastin. 



The driverant, from its large size and ferocity, and its habit of travelling in great swarms, 

 is feared l)y all living tilings, which tlee before it. Th<- photograph shows a male, twice the 

 natural size. 



Bengal ia dcprcssa. 



Dorylus nigricans. 



