360 INSECTS AT HO]\rE. 



supplies organs unless they have their work to do, and, as the 

 Bee is a parasitic one, there is no reason why it should take the 

 trouble of gathering pollen. Tlie name of CuculiuK, or Cuckoo- 

 bees, is given to them in consequence of their parasitic habits. 



In this genus the antennas are elbowed, and are nearly as long 

 as the thorax. The upper wings have one marginal and three 

 submarginal cells. The last segment of the abdomen is blunt 

 in the females and sliarp in the males. 



This is a most variable insect in point of colour, but it may 

 be generally described as rust-red, with three black longitudinal 

 lines in the thorax, and with yellow spots and bands on the 

 abdomen. There is but little difference in the dimensions of 

 the sexes. 



That these Bees are parasitic is well known, but the par- 

 ticular mode of parasitism is scarcely ascertained. 



They enter the burrows of certain Solitary Bees, and in those 

 burrows the young Nomadae are matured. It is supposed that 

 when the Solitary Bee has laid in its stock of pollen, the Cuckoo- 

 bee enters the burrow, deposits an egg, and goes off to repeat 

 the process elsewhere. When the real owner of the burrow 

 returns, she finds an egg already laid, takes it for her own, and 

 so goes away and makes afresh burrow. This, however, is only 

 conjectured, as is the theory that the parasite not only lays an 

 egg, but closes the burrow herself. 



One of the most curious points connected with these insects 

 is the fact that the Solitary Bee never interferes with the 

 parasite. Mr. F. Smith has the following remarks on this sub- 

 ject: 'I have on several occasions watched with much enjoy- 

 ment a large colony of Eucera longicornis ' (this will be pre- 

 sently described); 'the males occasionally darting forwards 

 with great velocity, then turning sharply round, and as it were 

 swimming in circles close to the ground ; then darting off again 

 and again in an unceasing round of sportive enjoyment. Their 

 industrious partners, whose whole existence appears to be bound 

 up in one unceasing round of labour, would occasionally return 

 home laden with food for their young progeny. 



' Sometimes it would happen that a Nomada had previously 

 entered her nest. When such proved to be the case, she 

 would issue from it, and, flying off to a short distance, wait 

 patiently until the parasite came forth, when she would 



