416 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



their hosts, as in the case of P. vestalis where it 

 attacks B. terrestris. The carnivorous grubs of 

 the bee-mimicking Diptera of the genus Volucella 

 prey largely upon the larvae of some of the Bombi, 

 but the grubs of Homalomyia found in their 

 colonies possibly act as scavengers there. Some of 

 the solitary ants, Mutillidce, live in the nests of 

 humble bees, but whether as enemies or friends is 

 not yet known ; other ants of various species often 

 pillage them for the sake of the honey. Many Cole- 

 optera, chiefly Stapliylinidm and Homolota, are 

 also found in the nests of this genus, some few 

 breeding there ;but the majority would appear to 

 be plunderers or casual visitors. Under the same 

 categories certain Hemiptera may be included. 

 The larva of a Lepidopteron, Aphomia sociella, 

 sometimes does great damage to the nest by 

 devouring the waxen cells. The humble bees 

 themselves are largely infested by an Acarid of 

 the family Gamasidce, P ceciloechirus fucorum, 

 Berk, in its nymphal form, whose larvae also 

 probably feed upon the wax in the nests of their 

 hosts ; they sometimes moreover become a prey to 

 the Dipteron Conops, whose grubs live within 

 their bodies and devour their viscera. 



B. venustus, Sm. — cognatus, Saund, nee, Steph. — senilis, 

 Sm. — variabilis, Schmied. — Fairly distributed, 

 but nowhere abundant. Specially noted West 

 Kirby, Bidston, Barnston ; Higher Bebington, 

 J.T.G. ; Hooton, R.N. ; Warrington, B.C.; 

 Wallasey, E.C.T. 



B. agrorum, Fab., Kirb., Smith, Schmied, Thorns. — 

 muscorum, Smith, Saund. — Widely distributed 

 and abundant. A colony in a willow-wren's 



