THE SOCIAL INSECTS 



PARASITIC ANTS 



The story of the development of cuckoo habits in ants is 

 more complicated. It has happened in a much bigger range 

 of species, and may have arisen in more than one way. 

 Moreover,' all sorts of stages in the development of such 

 behaviour are known, ending up in workerless, degenerate 

 parasites. 



One manifestation of such behaviour is the temporary 

 social parasitism of such species as the wood ant, Formica 

 rufa, mentioned in the previous chapter. A rather different 

 example is seen in the North African ant, Bothriomyrmex 

 decapitans. The queen of this species, after her marriage 

 flight, enters the nest of another ant, Tapinoma nigerrimum. 

 She does this by alighting near the nest and allowing herself 

 to be dragged in by the workers. She is subjected to some 

 rough treatment, but once inside the nest, she takes refuge 

 on either the head or the back of the much larger Tapinoma 

 queen. In either of these positions she seems to be safe from 

 the workers. After a time, she bites off the head of the 

 Tapinoma queen, but since by that time she has (presumably) 

 acquired the characteristic odour of the nest, she is readily 

 adopted as the new queen and her brood is reared. Gradually, 

 all the Tapinoma workers die off, and a pure colony of the 

 Bothriomyrmex remains. 



Similar and, from a human point of view, even less pleasant 

 behaviour has been observed by Bruch in an Argentinian ant, 

 Labauchena. Several of the very small queens of this species 

 invade a nest of the fire ant, Solenopsis, and climb onto the 

 back of the much bigger queen. There they co-operate in 

 gnawing off her head, an act which may take them many 

 days. 



Such methods of colony foundation are appropriate to 



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