HYMENOPTERA-ACULEATA. 415 



recorded in our neighbourhood. The inquiline 

 Ccelioxys is said to attack it. 



Leaving the above solitary genera, with male and female 

 only, we now come to bees which, with the exception of 

 the inquiline Psithyri, are social species. They live in 

 large communities, comprising males, females and 

 workers, all dwelling together in one nest. 

 Bombus, Latr. — A genus consisting of the well-known 

 Humble Bees. The females, aided by the 

 workers, construct nests of moss, grass, &c, in 

 which numbers, small or large according to the 

 species, are reared and live. Some kinds, such 

 as B. terrestris, lapidarius and hortorum, make 

 use of ready-made cavities more or less under- 

 ground ; while others, as B. venustus, agrorum, 

 sylvarum and pratorum, either build elaborate 

 nests of moss, grass, &c, above the surface, or 

 else adapt the old nests of ground-building birds 

 to their use. Those species that make their nests 

 in the ground often store up honey in con- 

 siderable quantities in the waxen cells which they 

 construct ; so much so, that many small animals, 

 such as mice, seek out the nests for purposes of 

 plunder, and in some rural districts, especially 

 in Scotland, the search for the nests of the red- 

 tailed " Bumble Bee," with its sweet-tasting con- 

 tents, is a recognised holiday pursuit of the 

 village schoolboy. 



Few Aculeates have more enemies than the 

 Bombi. Chief among these are the allied inqui- 

 line bees of the genus Psithyrus ; by appropri- 

 ating their nests, provisions and even workers, the 

 inquilines sometimes decimate the numbers of 



