410 Parasitic Beetles. 



the sake of its droppings, and possibly for such crumbs as fall 

 from its table. I am not aware whether the sand-martin 

 employs much (if any) dried twigs, grass, or leaves as a pad at 

 the bottom of its burrow ; if such be the case, however, it 

 would be of use in assisting to solve the question of the alliance 

 between bird and beetle, as another of the latter's genus, 

 Haploglossa praetexta, sometimes swarms in twigs, etc., at the 

 bottom of neglected hay-stacks. Another of its intimate allies, 

 Haploglossa gentilis (hereafter mentioned), is a parasite upon 

 ants; so that sycophancy seems to run in the family. H. 

 nidicola, being very small, is doubtless in some of its stages 

 unwittingly transported by the birds from one nest to another ; I 

 have never heard, however, of its being found in the nests of 

 any bird but the sand-martin, under banks perforated by which 

 it may be found in profusion. The nests of birds, on account 

 of their warmth, damp, etc., often serve as a home for beetles, 

 which in many cases may be originally introduced with the 

 substances of which they are built. A curious instance of this, 

 and somewhat entomologically akin to the accounts so often 

 to be read in provincial journals of birds building in unusual 

 or much frequented situations, is to be found in the capture 

 by Mr. E. Waterhouse of several specimens of the rare Dendro- 

 philus punctatus in sparrow's-nest rubbish stuck in a water- 

 pipe of the British Museum. Another species of Dendropliilus 

 (D. pygmcens) is a true ant-parasite, and D. punctatus has itself 

 been taken in nests of Formica rufa ; so that the parallel 

 between it and Haploglossa is, oddly enough, somewhat close. 



Drilus flavescens is constantly found in the vicinity of snails 

 (Helix nemoralis, etc.), for the simple reason that its larva feeds 

 upon those molluscs. It is, however, noteworthy on account 

 of the males only being known in this country (in certain chalky 

 parts of which, near Dover, Dartford, etc., it is not uncommon) ; 

 but the non-appearance of the other sex is not due to the same 

 cause (whatever it may be) as that which baffles us in the 

 endeavour to discover the males of certain abundant species of 

 Cynips (gall-insects). In the latter case persistent but un- 

 successful endeavours have been made (by breeding, etc.) to 

 solve the enigma ; but, as to the Drilus, failure is owing simply 

 to a want of sufficient experiment : for if any one assiduously 

 collected snails in the localities where the male occurs, the 

 female would assuredly be detected, as I have found the full- 

 grown female larva at the base of Shakespeare's Cliff, running 

 very quickly among empty snail-shells in the hot sunshine. 

 The two sexes — as in the glow-worm (Lanvpyris noclihica), to 

 which it is closely allied, and which is equally rapacious and 

 mollusc-devouring, ma I g re its poetical reputation — are very 

 dissimilar in appearance ; the male having wings and brown 



