188 



THE ENTOMOLOGIST S RECORD. 



attacks of the young first brood ^ ^ , kill the queen (t/. Exp. 14), and 

 be established in hci- place. If she happened on a queenless colony of 

 ni()er, even a populous one, she might, as I have shown elsewhere 

 {Science Gossip, May 1900, N.S., vol. vi., no. 72, p. 365, " Alien Queen 

 Ant; " Knt. Mo. M(ui., 2nd ser., vol xx., p. 94, 1909 ; Trans. Knt. Soc. 

 Loud., Parts iii. and iv., p. 657, 1909 ; etc.), readily be adopted by 

 the ^ ^ . 



I also made the following three experiments with colonies of L. 

 uinbratns and L. flams. 



Exp. 18. September 17th, 1912. — I isolated a young fertile 

 iiinbratiis $ and gradually introduced Kuihratns ^ ^ from an old mixed 

 colony of /(///f^ and iniibratiis, with queen and brood of the latter 

 species, dating from 1908 (nest 11). The ^ ^ were excited and some 

 attacked her. She was attacked from day to day and finally killed. 



Exp. 14. September 17th, 1912. — A young fertile nnibratiis J 

 was placed at the entrance to a nest of L. innbratus with two L. 

 fidif/inosHs queens and fnlii/inosits brood (nest 83, dating from 1910). 

 She entered the nest, but was attacked by the first ^ ^ that met her. 

 She walked on with her assailants hanging to her legs until she 

 reached one of the queens. She immediately sprang on the back of 

 the queen and seized her by the pedicel, the favourite point of attack. 

 Being hauipered by the ^ ^ , she was unable to hold the queen, who 

 escaped. Later in the day the intruder was killed. 



Exp. 15. September 17th, 1912. — Another young fertile iimbratiis 

 $ was put into a nest of /.. ti(iviis with queen. She was attacked and 

 killed. 



Experiment 14 is an ad)nirable illustration of what I take to be 

 the mode of attack when the intruder meets the rightful queen of the 

 nest. In Experiment 5, however, the innbratus $ made no attempt 

 to attack the queen, who was persistently friendly to her. 



Note on Antennophorus tjhlmanni. — The following occurrence 

 shows that ants, though unable to injure the hard bodies of these 

 semi-parasites with their mandibles, yet can easily kill them with 

 forniic acid. Ants of most species, however, have a great reluctance 

 to making use of their poison in the recesses of the nest, as in a 

 confined space the acid is fatal to the users themselves. In December, 

 1911, I removed an AntfinmijtJiorus from a ^ of L. iimbratiis and 

 placed it on its back on a slide. It vainly attempted to right itself by 

 using its long forelegs as levers. I then held an ant close to the 

 Antennophorus, which seized the ant's foreleg and ran with incredible 

 rapidity along the ant's body, finally returning to the underside of the 

 head, the usual position. I then again attempted to remove the 

 Antennophorus, but the ant, held by my forceps, began to struggle, and 

 a drop of formic acid appeared at the tip of its abdomen. The 

 AntennojihorHs came into contact Avith the acid, dropped off the ant, 

 and expired instantly. 



Though the ants sometimes feed these commensals, an ant will 

 always struggle violently for some time after one has fixed itself on 

 her, and an ant which bears an A)itennuphurns never seems to leave 

 the inner chambers of the nest. It seems fairly clear that the ants 

 only tolerate these tenacious Acari because their mandibles are not 

 powerful enough to remove them, and they are not sufliciently 

 intelligent to employ their formic acid to rid themselves of their 

 embarrassing burdens. 



