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MYRMECOPHILOUS NOTES FOR 1920. 21 



Myrmecophilous Notes for 1920. 



By HORACE DONISTHORPE, F.Z.S., F.E.S., etc. 

 In 1920 more time was devoted to Coleoptera than to Ants, never- 

 theless a certain number of observations and discoveries were made, 

 which are recorded here. 



FORMICIDAE. 



Myrmecina yrdnrinicola, Latr. — The colony of this species which I 

 obtained on May 1st, 1910 (see British A?its, p. 81, etc.) is still under 

 observation, and in a nourishing condition. For the first time for 

 four years no winged females have been reared, though $ $ have been 

 plentiful as usual. A. little fighting again took place in March ; but 

 did not last long. I have not recorded before that in August, 1919, 

 very serious fighting occurred in this nest, indiscriminately between 

 $ £ and del. ? 5 . One' £ might be attacked by two others, or by 

 two 2 ? , or by a $ and $ , or by one $ alone, or one 2 ; and the 

 same with one 5 . This lasted for nearly two months, and I was 

 much afraid I should lose the whole colony, as over 70, and perhaps 

 100, ants were killed off in this way. I cannot explain it, as the 

 colony had plenty of food, and a large brood to attend to. I put a 

 stop to it in the end by punishing any ant or ants who were fighting. 

 They were knocked off their legs with a paint brush, pushed about, 

 rolled over, and shaken up until they appeared to be thoroughly cowed ! 

 It is possible that this fighting may have been the cause why no females 

 were reared in 1920, and it will be of interest to see if such ? 2 will 

 be produced this year (1921), as no fighting to speak of, no ants being 

 killed, occurred last year. 



Acauthomyo/i.s (Donisthurpea) niger, L. — On March 4th, workers in 

 some numbers from a colony of this ant, nesting at the foot of a gate- 

 post at Putney,' were running about in the sun carrying bits of 

 earth, etc. 



On July 7th, at Mother Ivy's Bay, N. Cornwall, a fine colony of A. 

 (D.) niger, situated under a large flat stone near a stream running from 

 a marsh into tbe sea, was found to contain very many mermithogynes. 

 These short winged females from this nest (which also contained 

 numerous normal winged 9 5 and many 2 and £ cocoons, but no 

 $ $ ) are peculiar in themselves, in the fact that nearly every one of 

 them possesses a large oval hole in the mesonotum, about •7mm long 

 and -25mm. broad, the object of which I am quite unable to explain. 

 The gasters of such specimens as were dissected were found to con- 

 tain one, or two, worms in each. Most of the ants and brood of this 

 colony were taken, and as I knew my colleague Mr. Crawley was 

 working on a paper on mermithogynes, I handed them over to him 

 for investigation and experiment. The only other myrmecophiles 

 present in the nest were Platyarthrus hoftmanseggi, Brndt., and Cypho- 

 deints ( = Beckia) albinos, Nic. 



On August 28th marriage flights of niger (and also of A. (O.) flavus 

 and Myrmica ruginodis) took place in the afternoon and evening all 

 over Putney. 



Acanthomyops (Chthonolasius) mixtus, Nyl. — On August 11th very 



many dealated $ J were seen all over the heath at Weybridge ; and 



one winged individual was rescued from the clutches of a F. san- 



guinea $ . One example was observed entering a hole in the sand 



February, 1921. 



