4 BEES AND WASPS [OH. 



since in some male bees (Andrena) the enlargement 

 of the metatarsus is indistinct, we are constrained to 

 fall back on the habits of the insects in an endeavour 

 to discriminate between them. The technical name for 

 the "bees" is Anthophila (flower-lovers), and though 

 many of the "wasps" frequent flowers and nourish 

 themselves upon the nectar secreted by them, yet it 

 is the fact that none but the bees provision their 

 nests with the pollen of flowers, honey, etc. for the 

 benefit of their offspring. All the " wasps," notwith- 

 standing that when adult they feed upon plant pro- 

 ducts, supply their young with animal food, such as 

 spiders, caterpillars, or the flesh of larger carcases. 

 Here then we find a sure, though granted not an easy 

 means of distinguishing between "bee" and "wasp": 

 the bee grub is nourished upon vegetable products 

 collected by its mother or some other bee, the wasp 

 grub is carnivorous. 



The term "wasp" as here employed includes many 

 species of insects other than the familiar yellow and 

 black wasps that form large and often troublesome 

 societies in late summer and early autumn. For 

 convenience I use it to embrace the sand-wasps or 

 digger-wasps (Fossores) of every description, as well 

 as the solitary mud-wasps (Odynerus) and the social- 

 wasps known to everybody. Members of these two 

 last-named groups are easily recognisable by their 

 habit of folding their fore-wing along its entire 



