FORMICA. 261 



ton College the day before, into the last compartment of the nest, 

 the fusca colony being in the second compartment. The next morn- 

 ing, April 18th, the rufa female was in the first compartment with 

 three fusca workers ; she was not being attacked and must have 

 passed through the compartment containing the fusca during the 

 night. During the day she was attacked by three other workers 

 who entered her compartment, but she was not at all aggressive, 

 and tried to conciliate them by stroking them with her antennae. 

 Finally a worker dragged her by the jaws into the second compart- 

 ment, where she was accepted by the fusca colony, and always 

 remained with them. On June 1st one of the fusca females was 

 found bitten in two, and though this action was not actually 

 witnessed, there is little doubt that it was the work of the rufa 

 female, as she often rested with her head over one or the other of 

 the three fusca females. Later there were eggs in the nest, but it 

 was impossible to say whether the rufa female had laid any of 

 them, and on June 20th she died, but not from violence. Up to 

 November 26th the gaster of the dead rufa female was carried 

 about by one of the fusca workers 82 . 



This experiment also shows that for a time, at any rate, F. rufa 

 and F. fusca females may live amicably together. 



I have also made a number of other experiments in which rufa 

 females have been accepted into strange rufa and rufo-pratensis 

 colonies, as well as fusca colonies, but the above will be sufficient to 

 show the methods adopted by rufa queens under these circum- 

 stances. 



The following myrmecophiles have been found with Formica rufa 

 in Britain : 



Coleoptera : Aleochara ruficornis Gr., Microglossa pulla Gyll., 

 Oxypoda formiceticola Mark., 0. recondita Kr., 0. haemorrhoa Sahl., 

 Thiasophila angulata Er., Dinar da markeli Kies., Myrmedonia 

 humeralis Gr., Drusilla canaliculata F., Notothecta flavipes Gr., N. 

 confusa Mark., N. anceps Er., Homalota analis Gr., H. parallela 

 Man., Heterothops sp ? (nigra Kr ?), Quedius brevis Er., Stapliylinus 

 stercorarius 01., Xantholinus atratus Gr., Leptacinus formicetorum 

 Mark., Othius myrmecophilus Kies., Scydmaenus godarti Latr., 

 Batrisodes venustus Reich., Trichopteryx montandoni AIL, Ptilium 

 myrmecophilum All., Ptenidium myrmecophilum Mots., P. kraatzi 

 Mat., Coccinella distincta Fald., Hetaerius ferrugineus 01., Den- 

 drophilus punctatus Hbst., D. pygmaeus L., Myrmetes piceus Pk., 

 Monotoma conicicollis Aub., M. formicetorum Th., Cetonia aurata 

 L. (larvae and pupae), C. floricola Hbst. (larvae and pupae), and 

 Clythra quadripunctata L. (larvae and pupae). 



Formicidae : Formicoxenus nitidulus Nyl., Stenamma westwoodi 

 West., and Leptothorax acervorum F. 



Ichneumonidae : Microcryptus micropterus Gr., and Pezomachus 

 vulpinus Gr. 



