1922] on Biological Studies in Madeira 569 



In Madeira we have established a modus vivendi with the ant ; 

 we protect our food, our stores, our bees, and we spray our fruit 

 trees, finding that the ant has no further interest in them when the 

 Aphis and Coccus, which cater for it, are destroyed, and we have the 

 satisfaction of seeing our citrus fruits returning and our coffee plants 

 reviving. A very weak solution of corrosive sublimate is an effective 

 restraint, and a narrow circle of potassium cyanide in powder at the 

 foot of an infested tree will kill every ant coming and going in a 

 short time. After treatment with the cyanide I found that 47,000 

 ants had been engaged in draining a single lemon tree of its vitality, 

 and moreover that the destruction of the pest on this scale made no 

 difference in the numbers which, in forty-eight hours, arrived to 

 replace their defunct brethren in their destructive work on the lemon 

 tree in unaffected activity. I could forgive much if the presence of 

 the Argentine ant in Madeira had made any difference in the 

 prevalence of Pulex irritans, or the common house fly, but in the 

 larval state these creatures seem unattractive to the ant and have 

 not abated, though in the adult state they are greedily pursued. I 

 can conceive no foundation for a recent Daily Mail assertion that 

 the birds of Madeira have been destroyed by the Argentine ant, for 

 our gardens abound with every species, as in time past, and are 

 melodious with the full-throated song of the wild canary, the melody 

 of the blackbird, the robin and blackcap, as before the advent of the 

 Iridomyrex interloper. 



Far the most formidable of the few enemies of the ant in Madeira 

 is the Pholcus phalangioides, a sluggish being with a cylindrical body 

 and enormously long legs, well known in this country. This spider 

 spreads an untidy, loosely-stretched snare in every corner, and is 

 never without an ant in its mouth — the vast heap of dry-sucked 

 skins beneath testifying to its restraining efficiency. Nevertheless 

 there are signs that the first wild activity of the ant is now abating 

 and that the pace of its increase is slackening. 



The queens of this species are winged. The mating more often 

 takes place in the formicary than in a nuptial flight, and after a very 

 brief honeymoon, during which the female permanently discards her 

 wings, she issues forth with the workers to found a new colonv 

 wherever the conditions of food and shelter invite, and, discarding 

 the cares of motherhood, leaves the rearing of her prolific progeny to 

 the zealous care of her neuter associates. In overcoming obstacles 

 in search of food, the ant shows an intelligence and ingenuity which 

 are truly surprising. Hundreds will voluntarily drown and create a 

 bridge for the main body of assailants if they set their minds on 

 attacking a colony of bees isolated by protecting water. So likewise, 

 if they hear the buzz of a fly which has been caught on a sticky 

 fly-paper, they will patiently bridge the sticky surface with grit or 

 anything else they can carry until they arrive on a narrow pathway 

 to seize and dismember the unfortunate captive. Occasionally you 



Yol XXIII. (Xo. 116) 2 s 



