BEES ANDRENIDES 23 



occasions on which this bee has been found in Britain it was in 

 circumstances that left little doubt as to its being a parasite of 

 Andrena nigroaenea. Marchal ^ has seen S. st/hquadratus fight 

 with ITcdiefus malachurus, 



and kill it previous to taking r-^->.. ^*'^C^<i7#fe/*'*>*^ ..^^C^ 

 possession of its burrows ; \ ^$^^:5. ^W^?^// 

 and similar observations T^^^^^^^^^^^^^^^^^^-7 



have been made by Ferton. ^ ^^^^P^'^^^r^i^^^^^^^^ 



As the older observations of I ^^^'^'^^t^^'^^^^. 



Smith, Sichel, and Friese / /f^h^^^k\ \ 



leave little doubt that Sphe- [ M i__| ^ 



codes are sometimes indus- f S^^ \ 



trial bees, it is highly prob- ^ IjpP \ 



able that we have in this „ ,, ^ , , ,,, „ „ ., . 



Fig. 11. — Sphecodes gibhus $. Britain, 



genus the interesting con- 

 dition of bees that are sometimes parasitic, at other times 

 not ; but so much obscurity still prevails as to the habits of 

 Sphecodes that we should do well to delay accepting the theories 

 that have been already based on this strange state of matters.^ 

 Friese states that in Sphecodes the first traces of collecting 

 apparatus exist ; and, accepting the condition of affairs as being 

 that mentioned above, it is by no means clear whether we have 

 in Sphecodes bees that are abandoning the parasitic habit or com- 

 mencing it ; or, indeed, whether the condition of uncertainty 

 may not be a permanent one. It is difiicult to decide as to 

 what forms are species in Sphecodes owing to the great variation. 

 The Hymenopterist Forster considered that 600 specimens sub- 

 mitted to him by Sichel represented no less than 140 species, 

 though Sichel was convinced that nearly the whole of them 

 w^ere one species, S. gibhus. It has recently been found that the 

 male sexual organs afford a satisfactory criterion. The position 

 of Sphecodes in classification is doubtful. 



The great majority of the species of short-tongued bees found in 

 Britain belong to the genera Andrena and Halictus, and with some 

 others constitute the Andeenides of many writers. Hcdictus 

 includes our smallest British bees. Their economy escaped the 

 earlier observers, but has recently been to some extent unravelled 

 by Smith, Fabre, Nicolas, Verhoeff, and others, and proves to be 



^ Bull. Soc. ent. France, 1894, p. cxv. 

 - Marchal, Ecv. Sci. 15th February 1890, and Ferton, t.c. 19th April. 



