a4 INSECT TRANSFORMATIONS. 



indeed, the ruby-tail fly {Chrysis ignifa), on ap- 

 proaching this vigilant sentinel, fly off in all haste, 

 with evident fear of the consequences. But, as 

 Walckenaer justly remarks, should the partner of 

 its cares return from a foraging excursion, and take 

 two or three circular flights around the entrance to 

 announce its arrival, the sentinel bee immediately 

 makes way by withdrawing into the interior. Should 

 the sentinel bee be absent through any cause i'rom 

 its post, and the forager enter without announcing 

 its arrival, it is immediately driven back and punished 

 for so unpardonable a breach of etiquette*. 



Another circumstance worthy of notice in the 

 manners of these bees {Halicti) is, that they fly 

 directly into the entrance of their nests without ever 

 alighting upon any contiguous object, a circum- 

 stance which is attributed by Walckenaer to their 

 fear of enemies, numbers of which are always lurk- 

 ing about with evil intent. More than one species 

 of spider and several sorts of wasps lie in wait to 

 make prey of them, besides those we have men- 

 tioned as being on the alert to introduce their eggs 

 into their nest. But their most formidable enemy 

 is a solitary wasp (^Cerceris ornata), numbers of 

 which make their nes's in the very midst of their 

 colonies. The wasps surround the interior margin 

 of their holes with a ramjjart of sand, agglutinated 

 with a whitish mortar, and well polished. The gal- 

 lery is five inches deep, somewhat in the form of an S, 

 in which the female lays her eggs, with a store of 

 provisions for her future young, consisting of the 

 living bodies of her bee neighbours, the ^oov Halicti. 

 It is only on fine days, between eleven and four 

 o'clock, that the mother wasp engages in the chase 

 of the bees, and may be seen flying with the most 

 lively ardour around their nests. When an unfortu- 

 * VValck. Mem. dcs AbciUes Sulit. Paris, 1817. 



