418 Parasitic Beetles. 



The first of these, F. rufa, commonly known as the wood-, 

 hill-, or horse-ant, is of large size and red colour, with darker 

 abdomen ; it builds heaped up nests of a conical shape, com- 

 posed of twigs or any light rubbish not too bulky for transpor- 

 tation. Sometimes these nests, when undisturbed, are quite 

 two feet high ; and they are often constructed inside the trunks 

 of hollow trees or piled up against the outsides. The cells 

 appear to be formed in the ground, and the heap acts merely 

 as a shelter. 



Associated with this ant — which is a most pertinacious, 

 pungent, and pugnacious creature, holding on by its mandibles, 

 and allowing its body to be torn away, leaving the head and 

 jaws attached, rather than relinquish its bite ; and which, more- 

 over, has a pleasing habit of bringing its abdomen forward 

 between its hind-legs, and therefrom projecting an acrid juice 

 to some distance — are found some twenty species of beetles in 

 this country, the majority belonging to the Brachelytra. Of 

 these, perhaps, the most typical is Myrmedonia humeralis, 

 belonging to the genus of myrmecophilous beetles par excellence, 

 as all its members are either positively or by reputation ant- 

 parasites, one of them, indeed, M.canaliculata, being found with 

 nearly all ants, though also in other situations. The two 

 exceptions are M. Haworthi and H. collaiis, both considered 

 myrmecophilous, but I think erroneously ; the former is so 

 rare both here and abroad that there is no sufficient evidence 

 of its true habitat, all that have been found having occurred in 

 sandpits or among dead leaves ; and the latter is certainly a 

 wet-moss insect, occurring in the Norfolk Fens and on Wim- 

 bledon Common in Sphagnum. Our countryman, J. F. Stephens, 

 who first described the former of them, separated them both 

 from Myrmedonia, and formed two separate genera (not now 

 recognized) on their behalf. It is somewhat amusing to notice 

 the revolutions that take place in a few years both in nomen- 

 clature and collections. At the time of publication of that 

 author's manual, the secret of ant's nest hunting was either not 

 known or not appreciated in England; the result being that 

 the claim of divers species (now in every novice's cabinet) to a 

 place in our lists depended upon single specimens, found 

 "under a stone," or "flying," or under similar accidental 

 circumstances. 



In the nests of F. rufa are also found the following Brarfie- 

 lytra: — ThiasopliUa angulaia (and sometimes J 7 , inquilina), 

 JJinarda Mcerkelii (a small form of which occurs also "with /-'. 

 sanguinea) , the exceedingly rare Lomechusa strumosa, Oxypoda 

 formiceticola and 0. haemorrhoa, Homalota tmceps mid H.jlavipes, 

 Quedius brevis (some of whose congeners are above-mentioned 

 as either direct or indirect parasites on other insects), Lepta- 



